Nutrition and Eating Disorders

Nutrition and Eating Disorders Second Edition HE Eating Disorders.indd 1 8/23/10 3:57 PM HealtHy eating: a guide to...

Author: Lori A. Smolin | Mary B. Grosvenor

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Nutrition and Eating Disorders Second Edition

HE Eating Disorders.indd 1

8/23/10 3:57 PM

HealtHy eating: a guide to nutrition Basic Nutrition, Second Edition Nutrition and Disease Prevention Nutrition and Eating Disorders, Second Edition Nutrition and Food Safety Nutrition and Weight Management, Second Edition Nutrition for Sports and Exercise, Second Edition


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Nutrition and Eating Disorders Second Edition Lori A. Smolin, Ph.D., and Mary B. Grosvenor, M.S., R.D.


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Nutrition and Eating Disorders, Second Edition Copyright ©2011 by Infobase Publishing All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval systems, without permission in writing from the publisher. For information, contact: Chelsea House An imprint of Infobase Publishing 132 West 31st Street New York, NY 10001 Library of Congress Cataloging-in-Publication Data Smolin, Lori A. Nutrition and eating disorders / Lori A. Smolin and Mary B. Grosvenor. p. cm. — (Healthy eating: A guide to nutrition) Includes bibliographical references and index. ISBN 978-1-60413-802-3 (hardcover) ISBN 978-1-4381-3503-8 (e-book) 1. Nutrition–Juvenile literature. 2. Eating disorders–Juvenile literature. I. Grosvenor, Mary B. II. Title. III. Series. RA784.S5978 2010 616.85’26–dc22 2010005693 Chelsea House books are available at special discounts when purchased in bulk quantities for businesses, associations, institutions, or sales promotions. Please call our Special Sales Department in New York at (212) 967-8800 or (800) 322-8755. You can find Chelsea House on the World Wide Web at http://www.chelseahouse.com Text design by Annie O’Donnell Cover design by Alicia Post Composition by Infobase Publishing Illustrations by Sholto Ainslie for Infobase Publishing Cover printed by Bang Printing, Brainerd, Minn. Book printed and bound by Bang Printing, Brainerd, Minn. Date printed: November 2010 Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 This book is printed on acid-free paper. All links and Web addresses were checked and verified to be correct at the time of publication. Because of the dynamic nature of the Web, some addresses and links may have changed since publication and may no longer be valid.

Contents

Introduction

1 The Meaning of Food 2 How Food Nourishes You Y 3 Normal and Abnormal Eating 4 Eating Disorders: Who Is Affected and Why?

5 Body Image 6 A Healthy Body Weight 7 Anorexia Nervosa 8 Bulimia Nervosa 9 Binge Eating and Other Eating Disorders

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y Lori A. Smolin, Ph.D., and b Mary B. Grosvenor, M.S., R.D.

9 20 41 54 67 82 103 123 137

Appendix Dietary Reference Intakes

155

Healthy Body Weights

162

BMI-for-Age Growth Charts

164

Blood Values of Nutritional Relevance

166

USDA’s MyPyramid

167

Glossary

168

Bibliograhy

175

Further Resources

180

Picture Credits

182

Index

183

About the Authors

190

introduCtion

A

hundred years ago, people received nutritional guidance from mothers and grandmothers: Eat your carrots because they’re good for your eyes; don’t eat too many potatoes because they’ll make you fat; be sure to get plenty of roughage so you can more easily move your bowels. Today, everyone seems to offer more advice: Take a vitamin supplement to optimize your health; don’t eat fish with cabbage because you won’t be able to digest them together; you can’t stay healthy on a vegetarian diet. Nutrition is one of those topics about which all people seem to think they know something, or at least have an opinion. Whether it is the clerk in your local health food store recommending that you buy supplements or the woman behind you in line at the grocery store raving about the latest low-carbohydrate diet, everyone is ready to offer you nutritional advice. How do you know what to believe or, more importantly, what to do? The purpose of these books is to help you answer these questions. Even if you don’t love learning about science, at the very least you probably enjoy certain foods and want to stay healthy—

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NuTRITIONANDEATINGDISORDERS or become healthier. In response to this, these books are designed to make the science you need to understand as palatable as the foods you love. Once you understand the basics, you can apply this simple health knowledge to your everyday decisions about nutrition and health. The Healthy Eating set includes one book with all of the basic nutrition information you need to choose a healthy diet, as well as five others that cover topics of special concern to many: weight management, exercise, disease prevention, food safety, and eating disorders. Our goal is not to tell you to stop eating potato chips and candy bars, give up fast food, or always eat your vegetables. Instead, it is to provide you with the information you need to make informed choices about your diet. We hope you will recognize that potato chips and candy are not poison, but they should only be eaten as occasional treats. We hope you will decide for yourself that fast food is something you can indulge in every now and then, but is not a good choice every day. We encourage you to recognize that although you should eat your vegetables, not everyone always does, so you should do your best to try new vegetables and fruits and eat them as often as possible. These books take the science of nutrition out of the classroom and allow you to apply this information to the choices you make about foods, exercise, dietary supplements, and other lifestyle decisions that are important to your health. This knowledge should help you choose a healthy diet while allowing you to enjoy the diversity of flavors, textures, and tastes that food provides, and also encouraging you to explore the meanings food holds in our society. When you eat a healthy diet, you will feel good in the short term and enjoy health benefits in the long term. We can’t personally evaluate each meal you consume, but we believe these books will give you the tools to make your own nutritious choices. Lori A. Smolin, Ph.D., and Mary B. Grosvenor, M.S., R.D.

1 the Meaning of food

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ood provides the energy and raw materials we need to live, grow, and reproduce. But food does more than meet our physiological needs. From the time we are born, food is part of our interpersonal and emotional experience. A loving bond develops between young children and the caregivers who feed and nurture them. As children grow and become able to feed themselves, food continues to be a focus of social interactions and family traditions. Throughout life, our eating patterns are affected by the society in which we live. What we have available and what we view as acceptable, both personally and culturally, affect which foods we choose to eat. In addition, each person’s psychological and emotional states influence what and how much is eaten, and when it is eaten. Sometimes it is difficult to separate food’s physiological function from its psychological effects. When food takes on too much importance for reasons other than nutrition, eating behavior may become abnormal and an eating disorder may result. Although

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Nutrition and eating disorders eating disorders occur in both men and women, young women are most likely to develop eating disorders; in the United States, 3.2% of women between the ages of 18 and 30 are affected. The causes of these disorders are complex and multifaceted, but the emotional and sociocultural meaning that we place on food certainly plays a role.

Food and Emotions From birth, food is linked with affection. Infants suckling while cradled in their mothers’ arms experience physical and emotional satisfaction. This is a time when we are comforted by physical contact and the assurance that we are loved and all our basic needs are being met. During childhood, the associations among food, affection, and comfort are reinforced. When a child is sick, “comfort foods,” such as hot tea and chicken soup, help him or her feel better. Sometimes these comfort foods may be sweet or fattening treats that, at least momentarily, make us feel happy (Figure 1.1). As adults, the foods that comfort us in times of sadness and emotional distress often are the same foods that brought us comfort as children. Throughout life, providing food is considered an expression of love and friendship. People serve lemonade or coffee when friends visit. Grandparents offer cookies and other treats when grandchildren visit. Conversely, refusing food can be interpreted as rejection of the person who offers it. We also use food to express or moderate moods and emotional states. When people are sad, they may eat a chocolate bar or a bowl of ice cream. People choose foods that they associate with comfort, love, and security. Some foods are associated not only with love, but also with sexuality. For example, chocolate is a sensual treat that is a traditional Valentine’s Day gift. Food triggers our memories and the emotions that go along with them. Eating the same food today that you ate at a time earlier in your life can remind you of that time or experience. For example, eating a food your mother often served may give you the same


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Figure 1.1 “Comfort foods,” such as tea, chocolate, ice cream, and even soup, help us feel better when we are not feeling physically well or happy.

sense of comfort and security you felt at home as a child. Eating a meal you once shared with a loved one on a special occasion may bring back the intense emotions you felt at that earlier time. In the same vein, a bad experience with food may create negative associations with certain foods. For instance, if you once became ill after eating a food, you may avoid that food for the rest of your life.

Food Defines Who You Are Food is a part of our personal, socioeconomic, cultural, and religious identity. Sometimes, these identity messages are based on stereotypes. For example, the upper class may be associated with meals presented on fine china and served with a degree of ceremony. Some people may imagine sophisticated people eating rare, expensive foods, such as caviar and truffles. In contrast,


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Nutrition and eating disorders

For Love or Chocolate Few foods are as universally desired as chocolate. It is offered as a reward, a treat, and an expression of affection. It is eaten for comfort and loved for its smooth texture, sweet taste, and sensual appeal. When it was first introduced to Europe in the fifteenth century, it was the food of royalty. Through the centuries, it has been hailed as everything from an antidepressant to an aphrodisiac. What makes it so irresistible? It turns out that some people’s love of chocolate is not only due to its taste, but also to the effect it has on the brain. Eating chocolate leads the brain to produce compounds that dull pain and increase feelings of well-being. Chocolate also contains compounds that mimic the effect of marijuana. Dark chocolate contains more of these compounds than milk chocolate does, but scientists doubt that the amounts are great enough to have much effect. Even if we don’t get a “chocolate high,” chocolate may quicken the heart rate and make people feel alert and content because of the chemical stimulants it contains. Phenylethylamine is a stimulant in chocolate that raises blood pressure and blood sugar levels, making us feel alert and happy. Chocolate also provides caffeine and caffeine-related compounds, which act as stimulants. So, there seems to be a physiological as well as a sensual basis for the “chocoholic” in most of us. No wonder Americans buy $5 billion of chocolate every year.

some associate the lower social classes with frozen dinners in front of the television. We may assume that vegetarians are concerned about ecology and the environment, and that people who eat thick, rare steaks are macho. People sometimes choose certain foods to convey a particular image. Food also can be used as a reward or a punishment. A wellbehaved child is given a cookie, whereas a “bad” child is sent to bed without dinner. For some of us, this association continues into adulthood. We consider ourselves “good” when we eat healthy foods and “bad” when we overindulge in greasy fast food.


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Food also is used to define relationships within a family or culture. Within most cultures, powerful individuals eat well. The head of the family (usually the father) gets first choice of foods. In some cultures, this tradition is even more extreme: The men get their fill before the women are allowed to eat. Food is an integral part of our ethnic and religious identity. People in Asian cultures eat rice at every meal, and Italians grow up on pasta. Indian cuisine is recognized by curries, and Mexican food by refried beans and tortillas. Food patterns and ceremonies are among the most ingrained of all cultural traditions. Almost every religion has dietary rules or restrictions. Seventh-Day Adventists are vegetarians. Jews and Muslims do not eat pork. Sikhs and Hindus do not eat beef. Devout Jews follow kosher dietary laws. Catholics do not eat meat on Fridays during the season of Lent. Many religions have special foods to commemorate religious events or holidays. Muslims do not eat before sundown during the month of Ramadan in order to recognize the first revelation of the Qur’an (Koran). Jews eat the unleavened bread matzo during Passover to remember their ancestors’ flight from slavery in Egypt, which was too hasty to give them time to wait for bread to rise. Christians eat bread and drink wine during church services to commemorate Jesus’s Last Supper before his crucifixion.

Food and Social Interactions Food is a focus of social interaction. At special events, it is symbolic and commemorative. We reward life’s accomplishments and celebrate marriages and anniversaries with food, and even mourn our dead with feasts. A professional success, a new job, or a graduation may be celebrated with a special dinner. And what would a birthday be without a cake? Specific foods define certain holidays, both religious and nonreligious. We eat turkey on Thanksgiving to remember a meal the Pilgrims shared with Native Americans. Each of us associates holidays—such as Christmas, Easter, Passover,


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Fly Soup? How would you feel if you found a fly in your soup? Most of us would not be too happy; in our culture, we think of insects as contaminants, not food. This is not the case in many places around the world, however. Some societies rely on insects as a major source of dietary protein. Grasshoppers are eaten in Africa and are becoming popular in South Korea. Termites, which contain more protein per ounce than beef, are a common protein source in parts of Africa and Australia. Caterpillars and other insect larvae also are popular in parts of the world. In Mexico, caterpillars of the Giant Skipper butterfly are a delicacy, and in Africa, the larva of the Goliath beetle is collected from among the roots of the banana tree. Despite our aversion to eating insects, survival manuals point out that insects are a perfect choice when other food sources are not available. In 1995, when American fighter pilot Captain Scott O’Grady was shot down while flying over Bosnia, he survived in the forest by eating ants.

New Year’s, and Kwanzaa—with specific foods that are traditional within our families and culture. Food also is the centerpiece of everyday social interactions. We get together with friends for meals. The dinner table is often the center for communication within a family—a place where the experiences of the day are shared. Summer outings often center on a picnic or barbecue. This eating is not just for sustenance, but is social as well.

Why Do We Choose Certain Foods? There are many reasons we choose to eat the foods we do. Sometimes, we eat a food simply because it is put in front of us. However,


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our choices also depend on our personal or cultural preferences, on what foods we heave been exposed to, what is socially acceptable, as well as which foods we consider healthy.

What Is Available Availability is a major factor in determining what foods we eat. The foods available to a person or a population are affected by geography, socioeconomic factors, and health status. In underdeveloped areas, food choices may be limited to what is produced locally. In more developed locations, a greater variety is available due to the ability to store, transport, and process food that is grown and produced at distant locations. Even when foods are available in stores, they are not necessarily available to everyone in the population. Socioeconomic factors—such as income, education, and the availability of cooking facilities and transportation—affect the types of foods that people can choose. People with low incomes must limit the amount of money they spend on food; choice is often based on what is on sale. If people do not know how to prepare a food, they are not likely to buy it. People who do not have a stove or microwave cannot cook some foods at home, so they are restricted to eating precooked or cold meals. A college student who does not have a refrigerator cannot store perishable foods. Someone without a car can purchase only what he or she can carry home on foot or while riding on a bus or subway (Figure 1.2). Availability can be affected by lifestyle. Busy lives often leave little time to buy food and prepare meals. This may be a particular problem in single-parent families and in families in which both parents work. As a result, prepared foods, fast food, and restaurant meals have become a larger part of our overall diet. Health status also can affect the availability of food. People with food allergies, digestive disorders, and dental problems have limited food choices. People with diseases who require special diets are limited to foods that meet their dietary prescriptions.


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Figure 1.2â•‡ Sometimes our food choices are limited by what is available to us. Busy people will often choose to eat things that are easily available, quick to eat, and cheap, such as potato chips from a vending machine.

What You Prefer Availability affects what foods we have to choose from, but individual tastes and cultural, religious, and personal beliefs determine what we eat. A person’s preferences for taste, smell, appearance, and texture affect which foods are chosen and which are passed over. Personal beliefs also influence food choices; a vegetarian will not choose a meal that includes meat, and an environmentalist may not choose a food packaged in a nonrecyclable container.

Creatures of Habit Your habits also are important factors in determining which foods you choose. The foods and meal patterns you are exposed to as a child influence which foods you buy and cook as an adult.


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For example, you most likely eat three meals a day and have specific types of foods at these three meals. For most of us, breakfast might include cereal, toast, or eggs, while lunch is made up of soup or sandwiches. Would it seem strange to you to have a peanut butter sandwich for breakfast or a bowl of cereal for dinner?

What Society Teaches Us As children, we learn which foods are appropriate to consume under particular social circumstances. As we grow, peer pressure influences our food choices. A child may decide to try a new food because a friend eats it. A teen may change his or her diet to fit in with peers. The amount of food we eat also is affected by social settings. In some cases, we eat more because we are with

Fast Food Culture American culture has become a culture of speed and efficiency. Whether Americans are paying bills, putting gas in their cars, or eating meals, many focus on speed and efficiency. Gone are the days when the woman of the house spent hours shopping for and preparing a home-cooked meal that would be enjoyed by the whole family around the dinner table. Today, the “woman of the house” often holds down a full-time job, and spends her evening and weekend hours shuttling kids to soccer or violin practice. The modern American lifestyle, with its working parents, single-parent households, and multiple after-school events, leaves little time for home-cooked meals. As a result, many Americans have come to rely on frozen meals, fast food, takeout, and dining out to get them through the week. Currently, about 41% of adults eat some type of commercially prepared meals three times a week. Fast food is the most popular choice; 25% of adults and 30% of children (4 to 19 years old) eat fast food every day. In 1970, the purchase of foods prepared away from home accounted for about 26% of Americans’ annual food budget; today, it accounts for 46%.


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Nutrition and eating disorders friends, in other cases less. To impress a dining companion, we may choose foods different than those we normally would choose. Out of politeness, we also might eat foods that we typically avoid.

What Advertisers Sell Us The products we see advertised on television and in magazines can influence the foods we choose. Often, the sales of food products are proportional to the money that companies spend advertising them. Unfortunately, many products that are the focus of advertising campaigns are high in fat, sugar, or both. A review of commercials during children’s television shows found that most were for foods high in sugar, fat, or salt.

What We Think Is Good for Us Our ideas about a healthy diet affect our food choices. We may choose specific types of foods to try to lose weight. We may limit red meat intake to reduce our risk of heart disease, or purchase organic foods because we believe that pesticide exposure is harmful. Health concerns also sell products. Foods marketed to reduce the risk of cancer, lower cholesterol, or improve bone health sell well. For example, a campaign advertising the cholesterollowering properties of oats increased the sale of breakfast cereals by $1.5 billion in just two years.

Review We eat food to meet our physiological needs, but food is much more. Food also is psychologically nurturing. It is part of our personal, social, cultural, and religious identity. It is an essential component of our social interactions. There are many reasons we choose to eat specific foods. Often, it is because certain foods are more available to us in light of geographic or economic factors. What is available, however, also depends on living conditions, lifestyle, and health status. The foods we choose are influenced by


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our personal preferences for taste, smell, texture, and appearance. We also may have preferences based on our culture and personal convictions. Habits, social factors, exposure to advertising, and our beliefs about nutrition and health also affect food choice.


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2 hoW food nourishes You

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ood nourishes us emotionally and physically. People with eating disorders have poor diets because the psychological aspects of food become more important than the physiological factors. To understand the physiological and nutritional problems caused by disordered eating, and the importance of diet and nutrition in treatment, it is essential to have a basic understanding of nutrition. Nutrition encompasses all of the interactions that occur between people and food. Nutrition involves understanding which nutrients we need, where to find them in food, how they are used by our bodies, and the impacts they have on our health. Nutrition also considers society, culture, economics, technology, psychology, and emotions, which all play roles in food choice.

We get nutrients froM food We don’t eat individual nutrients; we eat food. Food provides the body with energy and nutrients. It also contains other substances,

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HowFoodNourishesYou such as chemicals found in plants called phytochemicals, which have not been defined as nutrients but which have health-promoting properties. When we choose the right combinations of foods, our diet provides the nutrients and other substances we need to stay healthy. If we choose poor combinations of foods, we may be missing out on some nutrients and consuming too much of others. There are more than 40 nutrients that are essential to human life. We need to consume these essential nutrients in our diets because our bodies either cannot make them at all, or cannot make them in large enough amounts to optimize health. Different foods contain different nutrients in varying amounts and combinations. For example, beef, chicken, and fish provide protein, vitamin B6, and iron. Bread, rice, and pastas provide carbohydrate, folic acid, and niacin. Fruits and vegetables provide carbohydrate, fiber, vitamin A, and vitamin C. Vegetable oils provide fat and vitamin E. Choosing a diet that provides enough of all the essential nutrients without excesses of calories or nutrients can be challenging. In addition to the nutrients found naturally in foods, many foods have nutrients added to them through fortification. Fortification can replace nutrients lost during processing or add particular nutrients to foods, for instance orange juice fortified with calcium. Dietary supplements also are a source of nutrients. Although most people can meet their nutrient needs without them, supplements can be useful for maintaining health and preventing deficiencies.

What do nutrients do? Nutrients provide three basic functions in the body. Some nutrients provide energy. Some provide structure. Some help to regulate the processes that keep us alive. Each nutrient performs one or more of these functions, and all nutrients together are needed for growth, to maintain and repair the body, and to allow us to reproduce.

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Energy Nutrients provide the body with the energy or fuel it needs to stay alive, to move, and to grow. This energy keeps your heart pumping, your lungs respiring, and your body warm. It also is used to keep your stomach churning and your muscles working. Carbohydrates, lipids, and proteins are the only nutrients that provide energy to the body. They are referred to as the energy-yielding nutrients. The energy used by the body is measured in calories or kilocalories (abbreviated as “kcalories” or “kcals”). In some other countries, food energy is measured in joules or kilojoules (abbreviated as “kjoules” or “kJs”). Each gram of carbohydrate we eat provides the body with 4 calories. A gram of protein also provides 4 calories. A gram of fat provides 9 calories, more than twice the calories of a gram of carbohydrate or protein. For this reason, foods that are high in fat are high in calories. Alcohol provides 7 calories per gram, but alcohol is not considered a nutrient because the body does not need it to survive. The more calories you use, the more calories you need to eat in order to maintain your weight. If you increase the amount

Is a Calorie a Kilocalorie? There are 16 calories in a teaspoon of sugar. Yet, if in your chemistry class you measured the amount of energy in a teaspoon of sugar, the result would be about 16,000 calories, or 16 kilocalories. This is because the “calories” we use in nutrition to refer to the energy content of food are really kilocalories. A kilocalorie is 1,000 calories. Sometimes, as is the case on food labels, calorie is spelled with a capital “C” to indicate that it is referring to kilocalories. In the popular press, however, the term calorie with a lower case “c” is typically used to express the kilocalorie content of a food or of a diet. Therefore, when you eat a cookie that has 50 calories, keep in mind that it really has 50 kilocalories, or 50,000 calories.


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of exercise you get without increasing the amount of food you eat, you will lose weight. If you eat more but do not increase the amount of exercise you get, your body will store the extra energy (mostly as fat) and you will gain weight. When you consume the same number of calories as you use, your body weight remains the same—this means you are in energy balance.

Structure There is truth to the saying, “You are what you eat.” All of the structures in our bodies must be formed from the nutrients in our diet. By weight, our bodies are about 60% water, 16% protein, 16% fat, and 6% minerals. Water is a structural nutrient because it plumps up our cells, giving them shape. Protein forms the structure of our tendons, ligaments, and muscles. Lipids are the major component of body fat. Muscles and fat help give the body its shape. The minerals calcium and phosphorus harden bones, which provide the structural frame of the human body and determine height and the length of arms and legs.

Regulation Nutrients also are important regulators of body functions. For the body to function normally, all of the processes that occur in our bodies—from the breakdown of carbohydrate and fat to provide energy to the building of bone and muscle to form body structures—must be regulated. For example, the physiological processes that maintain body temperature must be regulated to prevent it from rising above or falling below the healthy range. This constant internal body environment is called homeostasis. Maintaining homeostasis requires many different nutrients. Carbohydrates help to label proteins that must be removed from the blood. Water helps to regulate body temperature. Lipids and proteins are needed to make regulatory molecules called hormones, and certain protein molecules, vitamins, and minerals help to regulate the rate of chemical reactions within the body.


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Getting Nutrients to Your Cells To get nutrients to the cells where they are needed, food must be digested and the nutrients absorbed. Digestion breaks food into small molecules and absorption brings these substances into the body, where they are transported to cells. The digestive system is responsible for the digestion and absorption of food (Figure 2.1). The main part of this system is the gastrointestinal tract, also called the GI tract. This hollow tube starts at the mouth. From there, food passes down the esophagus into the stomach and then on to the small intestine. Rhythmic contractions of the smooth muscles lining the GI tract help mix food and propel it along. Substances, such as mucus and enzymes, are secreted into the GI tract to help with the movement and digestion of food. The digestive system also secretes hormones into the blood that help regulate GI activity. Most of the digestion and absorption of nutrients occurs in the small intestine. Once absorbed, nutrients are transported in the blood to the cells. Anything that is not absorbed passes into the large intestine. Here, water and small amounts of some other nutrients can be absorbed. The remaining wastes are excreted in the feces.

How the Body Uses Nutrients Once inside body cells, carbohydrates, lipids, and proteins are involved in chemical reactions. The sum of these chemical reactions is called metabolism. The chemical reactions of metabolism synthesize the molecules needed to form body structures, such as muscles, nerves, and bones. The reactions of metabolism also break down carbohydrates, lipids, and proteins to yield energy in the form of ATP (adenosine triphosphate). ATP is a molecule used by cells as an energy source to do work, such as to pump blood, contract muscles, or synthesize new body tissue.


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HowFoodNourishesYou

figure 2.1 The digestive system consists of the gastrointestinal tract (mouth, esophagus, stomach, small intestine, and large intestine) and accessory organs that secrete substances that aid digestion and absorption (salivary ( glands, liver, and pancreas). Beginning with the first bite, the digestive system starts the process of breaking down food so the body can absorb its nutrients and use them to provide energy, structure, and regulations.

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The Six Classes of Nutrients The nutrients we need come from six classes: carbohydrates, lipids, proteins, water, vitamins, and minerals. Each class, with the exception of water, includes a variety of molecules used by the body in different ways (Table 2.1). Some classes of nutrients are needed in relatively large amounts, whereas others meet needs when

Bacteria in Your Intestine Did you know that your large intestine is home to several hundred species of bacteria? You provide them with a nice warm home with lots of food, and they do you some favors in return—if they are the right kind. The right intestinal bacteria improve the digestion and absorption of essential nutrients, make some vitamins, and break down harmful substances, such as ammonia. They are important for intestinal immune function, proper growth of cells in the large intestine, and optimal movement through the GI tract. A healthy population of intestinal bacteria may also help prevent constipation, gas, and excess stomach acid. However, if the wrong bacteria take over, the result could be diarrhea, infections, and perhaps an increased risk of cancer. How can you make sure the right bacteria are in your gut? One way is to eat them. This is referred to as probiotic therapy. Live bacteria are found in some foods, such as yogurt and acidophilus milk. They also can be purchased as bottled suspensions or tablets. One problem with probiotic therapy is that the bacteria are washed out of the colon if you stop eating them. A second approach that can modify the bacteria in your gut is to consume foods or other substances that encourage the growth of particular types of bacteria. Substances that pass into the large intestine and serve as food for the healthy bacteria are called prebiotics. Prebiotics are sold as dietary supplements, but don’t run to the store just yet. For most of us, eating a healthy diet supports a healthy population of intestinal bacteria.


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Table 2.1 Categories of Nutrients Nutrient Category

Nutrients included

Macronutrients Carbohydrates

Sugar, starch, and fiber

Protein

Proteins and amino acids

Lipids

Triglycerides, fatty acids, phospholipids, and sterols (including cholesterol)

Water

Water

Micronutrients Vitamins

Fat-soluble vitamins: Vitamins A, D, E, and K Water-soluble vitamins: Vitamins C, B6, B12, thiamin, riboflavin, folate, niacin, pantothenic acid, and biotin

Minerals

Major minerals: Sodium, potassium, chloride, calcium, phosphorus, magnesium, and sulfur Trace minerals: Iron, copper, zinc, manganese, selenium, iodine, fluoride, chromium, and molybdenum

tiny amounts are consumed. Carbohydrates, lipids, proteins, and water often are referred to as macronutrients, because they are required in the diet in relatively large amounts. Vitamins and minerals are referred to as micronutrients, because they are needed only in small amounts.

Carbohydrates Carbohydrates include sugars, starches, and fiber. Sugars are the simplest form of carbohydrate. They are made up of one or two sugar units. They taste sweet and are found in fruit, milk,


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Nutrition and eating disorders and sweeteners, such as honey and table sugar. Starches are made of many sugar units linked together. They do not taste sweet. Starches are found in cereals, grains, and starchy vegetables, such as potatoes. Starches and sugars are good sources of energy in the diet, and provide 4 calories per gram. Most fiber also is carbohydrate. Good sources of fiber include whole grains, legumes (peas and beans), fruits, and vegetables. Fiber provides little energy because it cannot be digested or absorbed. It is, however, important for the health of the gastrointestinal tract.

Lipids Lipids are commonly called fats. Fat is a concentrated source of energy in our diet and in our bodies, providing 9 calories per gram. Most of the fat in our diet and in our bodies is in the form of triglycerides. Each triglyceride contains three fatty acids. Fatty acids are made up of chains of carbon atoms of varying lengths. Depending on how these carbons are linked together, fats are classified as either saturated or unsaturated. Saturated fats are usually solid at room temperature. They are found mostly in animal products, such as meat, milk, and butter. Unsaturated fats are found in vegetable oils, and are usually liquid at room temperature. Small amounts of certain unsaturated fatty acids are essential in the diet. Cholesterol is another type of lipid found in animal foods. Diets high in saturated fat and cholesterol may increase the risk of heart disease. A type of unsaturated fat called trans fat also promotes heart disease.

Protein Protein is needed for growth, maintenance, and repair of body structures and for the synthesis of regulatory molecules such as enzymes and some hormones. Protein also can be broken down to provide energy (4 calories per gram of protein). Protein is made of folded chains of units called amino acids. The number and order of amino acids in the chain determine the type of protein. The right amounts and types of amino acids must be consumed


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in order to build the proteins that the body needs. Animal foods, such as meat, poultry, fish, eggs, and dairy products, generally supply a combination of amino acids that meets human needs better than plant proteins do. However, vegetarian diets that contain only plant foods—such as grains, nuts, seeds, vegetables, and legumes—also can meet protein needs.

Water Water is an essential nutrient. By weight, water makes up about 60% of an adult’s body. It provides no energy, but is needed in the body to transport nutrients, oxygen, waste products, and other important substances. It also is needed for many chemical reactions, for body structure and protection, and to regulate body temperature. Water is found in beverages as well as solid foods. Water is not stored in the body, so to maintain proper hydration, water intake must balance water losses in urine, feces, and sweat, as well as from evaporation.

Vitamins Vitamins are small, carbon-based molecules needed to regulate metabolic processes. They are found in nearly every food, but no one food is a good source of all vitamins. Some vitamins are soluble in water and others in fat. This affects how vitamins are absorbed into and transported through the body. Vitamins do not provide energy, but many of them are needed to regulate the processes by which the body extracts energy from carbohydrates, fats, and protein. Some vitamins are antioxidants; they protect the body from reactive oxygen compounds, such as free radicals. Other vitamins have roles in tissue growth and development, bone health, and blood-clot formation.

Minerals Minerals are single elements such as iron, calcium, zinc, and copper. Some are needed in the diet in significant amounts, whereas others are needed in extremely small amounts. Like vitamins,


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Nutrition and eating disorders minerals provide no energy, but they perform a number of diverse functions. Some regulate chemical reactions. Others participate in reactions that protect cells from oxidative damage. Still others have roles in bone formation and maintenance, oxygen transport, and immune function.

How Much Of Each Nutrient Do You Need? To stay healthy, adequate amounts of energy and of each essential nutrient must be consumed. How much you need depends on your age, size, gender, genetic makeup, lifestyle, and health status. The Dietary Reference Intakes (DRIs) are general recommendations for the amounts of energy (calories), nutrients, and other substances that should be consumed on an average daily basis in order to promote health, prevent deficiencies, and reduce the incidence of chronic (long-lasting) disease.

The Dietary Reference Intakes (DRIs) The DRIs include recommendations based on age, gender, and, when appropriate, pregnancy and lactation. The recommendations for nutrient intakes include four values. The Estimated Average Requirements (EARs) are the amounts of nutrients estimated to meet the average needs of the population. They are not used for individual people. They are used for planning and evaluating the nutrient intake of population groups. The Recommended Dietary Allowances (RDAs) and Adequate Intakes (AIs) are amounts calculated to meet the needs of nearly all healthy people in each gender and life-stage group. These can be used to plan and assess individual diets. The fourth set of DRI values is the Tolerable Upper Intake Levels (ULs). These are the maximum levels of intake that are unlikely to pose a risk of adverse health effects. ULs can be used as a guide to limit intake, as well as to evaluate the possibility of excessive intake. When a person’s diet


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provides the RDA or AI for each nutrient and does not exceed the UL, his or her risk of nutrient deficiency or toxicity is low. The recommendations for energy intake are expressed as Estimated Energy Requirements (EERs). These values predict the calories needed to maintain weight in healthy individuals. They are based on age, gender, body size, and activity level. Formulas for calculating EERs are included in Chapter 6.

What Happens if You Get Too Little or Too Much? Consuming either too little or too much of one or more nutrients or energy can cause malnutrition. Typically, we think of malnutrition as a lack of energy or nutrients. This occurs when food is lacking and when the diet is not well planned. Yet, undernutrition also can be caused by an increase in dietary needs, or when the body stops being able to absorb or use nutrients. A deficiency of energy is called starvation. It causes a loss of body fat and muscle mass, resulting in an emaciated appearance

Too Much of a Good Thing Can Kill You We usually think of the vitamins and minerals in supplements as a healthy addition to our diets, but too much can be dangerous. Taking too many dietary supplements can cause nerve damage, kidney stones, liver and heart damage, and in extreme cases, death. For example, high doses of vitamin B6 can cause tingling, numbness, and muscle weakness. High doses of niacin cause flushing of the skin. Too much vitamin C can cause diarrhea. Overdosing on iron from children’s vitamin/mineral supplements is one of the leading causes of poisoning in children under age six. To be safe, take supplements according to the recommended doses and use the ULs from the DRIs to check for toxic doses.


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Figure 2.2â•‡ Both starvation and obesity are forms of malnutrition. People living in regions with widespread food shortages often exhibit the same symptoms of starvation as seen in those with anorexia nervosa. Above, 4-year-old Abdia Abdi Liban suffers from starvation in western Somalia, where a drought has caused widespread famine.


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(Figure 2.2). This is the type of malnutrition seen in people who suffer from anorexia nervosa. Malnutrition due to an individual nutrient deficiency will cause symptoms that reflect the functions of that nutrient. For example, vitamin D is needed for strong bones. A deficiency of vitamin D causes the leg bones of children to bow outward, because they are too weak to support the body weight. Vitamin A is needed for healthy eyes; a deficiency can result in blindness. For many nutrient deficiencies, supplying the lacking nutrient can quickly reverse the symptoms. Overnutrition, an excess of energy or nutrients, is also a form of malnutrition. An excess of energy causes obesity, which is commonly seen in people with binge-eating disorder. Obesity increases the risk of developing certain diseases, such as diabetes and heart disease. Excesses of saturated fat, trans fat, cholesterol, and sodium also can increase the risk of heart disease. Excesses of vitamins and minerals rarely occur from eating food, but are seen with overuse of dietary supplements. For example, consuming too much vitamin B6 can cause nerve damage. Excess iron intake can cause liver failure.

Tools for Choosing a Healthy Diet Knowing which nutrients your body needs to stay healthy is the first step in choosing a healthy diet, but knowing how many milligrams of niacin, micrograms of vitamin B12, grams of fiber, or what percent of calories from carbohydrate should be included in a healthy diet doesn’t help you decide what to eat for breakfast or pack for lunch. A variety of tools have been developed to help you make these kinds of choices. A discussion of three of them—standardized food labels, the Dietary Guidelines for Americans, and MyPyramid—is below.

Understanding Food Labels Food labels are a tool designed to help consumers make healthy food choices. They provide information about the nutrients in packaged foods. Food labels also show how a serving of a given food fits into the recommendations for a healthy diet.


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What Can You Believe? “Lose 10 pounds in a week!” Weight loss diets and products often make fabulous claims. Can you believe everything you read? How can you tell what is fact and what is fantasy? Generally, the rule is if it sounds too good to be true, it is. The following tips offer some suggestions for evaluating nutritional claims: ●âŠ‘

●âŠ‘

●âŠ‘

●âŠ‘

●âŠ‘

Think about it. Does the information presented make sense? If not, disregard it. Consider the source. Where did the information come from? If it is based on personal opinions, be aware that one person’s perception does not make something true. Ponder the purpose. Is the information helping to sell a product? Is it making a magazine cover or newspaper headline more appealing? If so, beware: The claims may be exaggerated to help the sale. View it skeptically. If a statement claims to be based on a scientific study, think about who did the study, what their credentials are, and what relationship they have to the product. Do they benefit from the sale of the product? Finally, evaluate the risks. Be sure the expected benefit of the product is worth the risk associated with using it.

Almost all packaged foods must carry a standard food label. Raw fruits, vegetables, fish, meat, and poultry are not required to carry individual labels, but the nutrition information is often posted on placards in the grocery store or printed in brochures. Food labels must include both an ingredient list and a “Nutrition Facts” panel. The ingredient list includes all substances contained in the food, including additives, colors, and flavorings. The ingredients are listed in order of their prominence by weight. Therefore, a


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label that lists water first indicates that most of the weight of that food comes from water. You can look at the ingredient list if you are trying to avoid certain foods, such as animal products or foods to which you have an allergy. The “Nutrition Facts” portion of a food label lists the serving size of the food, followed by the total calories, calories from fat, total fat, saturated fat, trans fat, cholesterol, sodium, total carbohydrate, dietary fiber, sugars, and protein per serving (Figure 2.3). The amounts of all of these nutrients are given by weight. Most also are given as a percent of the Daily Value. Daily Values are standards developed for food labels. They help consumers see how a food fits into their overall diet. For example, if a food provides 10% of the Daily Value for fiber, then the food provides 10% of the daily recommendation for fiber intake in a 2,000-calorie diet. The amounts of vitamin A, vitamin C, iron, and calcium also are listed as a percent of each Daily Value. In addition to the required nutrition information, food labels often highlight specific characteristics of a product that might be of interest to the consumer, such as “low in calories” or “high in fiber.” The Food and Drug Administration (FDA) has developed definitions for these nutrient content descriptors. For example, a food labeled “low fat” can provide no more than 3 grams of fat per serving. Food labels also can include specific health claims if they are relevant to the product. For example, the label on oatmeal may claim that it helps to lower blood cholesterol. These claims are permitted on labels only if the scientific evidence for the claim is reviewed by the FDA and found to be strong.

The Dietary Guidelines The Dietary Guidelines for Americans includes recommendations designed to help you choose a diet and lifestyle that will promote health and reduce chronic disease risks. The Dietary Guidelines recommend choosing a variety of nutrient-dense foods. These include vegetables, fruits, whole grains, low-fat dairy products, lean meats, beans, nuts, and seeds. This type of diet is rich in fiber, micronu-


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NuTRITIONANDEATINGDISORDERS

figure 2.3 Standard “Nutrition Facts” labels, like this one, appear on all packaged foods. They provide information about the number of calories and the amounts of fat and other nutrients that are in each serving of the packaged food. The label is designed to help consumers make informed choices about the food they eat.


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trients, and phytochemicals, and low in saturated and trans fats. The key recommendations of the Dietary Guidelines (Table 2.2) are appropriate for all healthy Americans two years of age and older.

MyPyramid MyPyramid is a tool designed to help consumers choose foods that meet the recommendations of the Dietary Guidelines. This food guide divides foods into five groups based on the nutrients they provide; a sixth group consists of oils. The five food groups—grains, vegetables, fruits, milk, and meat and beans—and oils are represented by colored triangles that make up the pyramid. The shape of the Pyramid helps emphasize the recommendations for the amounts of food from each of the groups (Figure 2.4). Foods in the wider base of each triangle of MyPyramid contain the most nutrients per calorie; they have the highest nutrient density. Foods in the narrow tip of each triangle are lower in nutrient density. The figure climbing the pyramid emphasizes the importance of physical activity. Choosing the recommended amounts and varieties of foods from each group provides a diet that will help promote health, prevent disease, and support activity.

Table 2.2 Key recommendations of the Dietary Guidelines for Americans 2005 ●âŠ‘ Consume

a variety of foods within and among the various food

groups. ●âŠ‘ Balance calorie intake with expenditure to manage body weight. ●âŠ‘ Be physically active every day. ●âŠ‘ Choose more fruits and vegetables, whole grains, and low-fat dairy products. ●âŠ‘ Choose fats wisely. ●âŠ‘ Choose fiber-rich carbohydrates and limit added sugars. ●âŠ‘ Choose and prepare foods with little salt. ●âŠ‘ If you drink alcoholic beverages, do so in moderation. ●âŠ‘ Prepare, handle, and store food safely.


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You can find your MyPyramid plan by going to mypyramid. gov, selecting MyPyramid Plan, and entering your age, gender, and activity level. The MyPyramid web site also provides other interactive tools to help users identify their calorie needs, choose nutrient-dense foods, plan healthy diets, analyze what they are eating, and estimate the calories they expend in activity.

Review Food provides our bodies with energy and nutrients. Energy is measured in calories. Nutrients are needed for growth, reproduction, and maintenance. The right number of calories is needed to keep weight in the healthy range and the right combination of nutrients is needed to maintain health. There are six classes of nutrients. Carbohydrates include sugars, starches, and fiber. Sugars and starches provide energy: 4 calories per gram. Fiber provides little energy because it cannot be digested by human enzymes and therefore cannot be absorbed. Lipids are a concentrated source of calories in the diet and in the body, providing 9 calories per gram. They are also needed to synthesize molecules that help regulate body processes. Proteins are made from amino acids. In the body, proteins can provide energy but are more important for their structural and regulatory roles. Water is the most abundant nutrient in the body. Water intake must equal output to maintain balance. Vitamins and minerals are needed in the diet in small amounts. They have regulatory roles, and some minerals also provide structure. Consuming too

(opposite page) Figure 2.4â•‡ MyPyramid is designed to educate people about the amounts they should eat of each food group in order to maintain a balanced diet. The amounts vary depending on individual calorie needs and can be obtained by going to www.mypyramid.gov and entering age, gender, and activity level.


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food groups BY the nuMBers Using a food group system like MyPyramid to guide food intake in the United States is not new. The first food group system, or food guide, was published in 1916. It was called Food for Young Y Children. It divided food into five groups: milk/meat, cereals, vegetables/fruits, fats/fatty foods, and sugars/sugary foods. During the Great Depression, a food guide consisting of 12 food groups was developed and released to help families save money on groceries. In 1943, shortages brought on by World War II led to the release of a food guide called the “Basic Seven.” Because of the complexity of the Basic Seven, in 1956 it was condensed to the Basic Four. The Basic Four included milk, meats, fruits and vegetables, and grain products. This guide was used for the next 20 years. In the late 1970s, concerns about the role of diet in the development of chronic disease began to intensify. The United States Department of Agriculture added a fifth category to the Basic Four: fats, sweets and alcoholic beverages, which people were advised to consume in moderation. In 1992, the Food Guide Pyramid was introduced. It used a pyramid shape to emphasize the relative contribution that each of six food groups should make to a healthy diet. In 2005, it was replaced by MyPyramid. Food guides are not unique to the United States. Those developed in other countries use a variety of shapes and numbers of groups to emphasize the proportions of foods that should make up a healthy diet. Korea and China use a pagoda shape. Mexico, Australia, and most European countries use a pie or plate shape. Canada uses a rainbow.

much or too little energy or nutrients results in malnutrition. The Dietary Reference Intakes (DRIs) recommend amounts of energy and nutrients needed to promote health, prevent deficiencies, and reduce the incidence of chronic disease. Food labels, the Dietary Guidelines for Americans, and MyPyramid provide information and recommendations that help people choose foods that make up a healthy diet.

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ood does more than nourish us. As previously discussed, it has meaning at the personal, social, cultural, and emotional levels. If our feelings about food come into conflict at any of these levels, it is likely to affect our relationship with food. In such cases, food and eating may take on more significance than is healthy.

What is norMaL eating? How do you know if you are eating normally? On some days, you may eat twice as much as you do on other days. One day at lunch, you may go out and stuff yourself; the next day, you may have just a salad. Some days, you may consume only snacks and fast food because you don’t have time to prepare healthy meals. Other days, you may have time to prepare three balanced meals. Some days, you may feel hungry all the time, while on other days, you seem to have no appetite. All of this is normal.

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Nutrition and eating disorders Normal eating patterns are flexible; sometimes people overeat, and sometimes they under-eat. What and how much people eat varies in response to emotions, time limitations, hunger, and the proximity of food. Normal eating sometimes may involve choosing foods to maintain weight and meet recommendations for a healthy diet. But generally, people eat when they are hungry, choose foods they enjoy, and stop eating when they are satisfied.

Why Do We Eat? In addition to the many meanings that food has in our lives, we have a basic biological need to eat. We need food to fuel our bodies and provide it with the essential nutrients that support life. The decision to put food in your mouth at a particular time is the result of the interplay among the biological need for food, the sensory pleasure it provides, and the emotional and sociocultural meanings it holds (see Chapter 1). This is illustrated by the fact that food consumption is stimulated by both hunger and appetite. Hunger is the physiological drive to eat food. Appetite is the drive to eat specific foods; it is not necessarily related to hunger. We tend to eat lunch around noon because it has been hours since we had breakfast and our bodies need more food, but also because social convention dictates that lunch be eaten at or around 12:00 p.m. After we eat, we experience satiety, the feeling of fullness and satisfaction that follows food intake and signals us to stop eating. The signals that tell us to eat or to stop eating can be external, coming from the sensory and sociocultural signals all around us. They also can be internal, originating from the GI tract, circulating nutrients, or from higher centers in the brain.

External Factors That Affect Eating Behavior Some of the same external factors that affect which foods we choose also stimulate or suppress eating behavior. These include the sight, taste, and smell of food; the time of day; social conventions; the

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appeal of the foods available; and cultural or religious rituals. For example, even if you have eaten a meal recently and are not hungry, you may snack on cookies or cinnamon rolls while walking through the mall because the smell entices you to buy them. Likewise, external factors such as religious dietary laws, negative experiences associated with certain foods, or an uncomfortable social setting can cause you to stop eating. Psychological factors can also affect appetite and eating behavior. Appetite often is closely connected to emotions. The effect that emotions have on appetite depends on the individual. Some people eat for comfort and to relieve stress. Others may lose their appetite in these same situations.

Internal Factors That Affect Eating Behavior In addition to external signals, signals from inside our bodies also stimulate hunger or signal satiety (Figure 3.1). The simplest type of

Does Lunchtime Make Your Mouth Water? Are you hungry at mealtimes, or does the time of day when a meal is expected make you feel hungry? Long-term associations between food and circumstance, such as the time of day or a particular place, can condition you to expect food and feel hungry when that situation occurs. This desire to eat is due to a conditioned response. It is why Pavlov’s dogs salivated at the sound of a bell. Ivan Pavlov was a Russian scientist. In 1904, he was awarded the Nobel Prize for his studies on digestion. While doing experiments on digestion in dogs, he noticed that after the dogs got used to a feeding routine, they began to salivate in response to some of the pre-feeding activities. To test this observation, he began to ring a bell whenever he fed the dogs. After a time, the dogs began to salivate whenever they heard a ringing bell, even if they could not see or smell any food. Does your mouth water when the clock strikes 12?


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figure 3.1 Whether we feel hungry or full is influenced by a variety of internal physiological signals and external stimuli. Tempting T smells, low blood sugar, and an empty stomach can trigger hunger and nutrients in the intestines and blood can cause satiety.

signal about food intake comes from local nerves in the walls of the stomach and small intestine. They sense the volume or pressure of food and send a message to the brain to either stimulate or inhibit food intake. The presence of nutrients in the gastrointestinal tract also sends information directly to the brain and triggers the release of hormones that cause satiety. Absorbed nutrients also may send messages to the brain to influence food intake.


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Levels of nutrients that circulate through the body are monitored by the brain and may trigger signals to eat or not to eat. Nutrients taken up by the brain may affect neurotransmitter concentrations, which then influence the amount and type of nutrients we take in. For example, some studies suggest that when a neurotransmitter called serotonin is low, we crave carbohydrates, but when it is high, we prefer protein. The liver also may be involved in signaling hunger and satiety. Water-soluble nutrients are sent directly to the liver after they are absorbed. Changes in liver metabolism—in particular, the amount of adenosine triphosphate (ATP)—are believed to modulate food intake. The pancreas is also involved in food intake regulation because it releases the hormone insulin, which may affect hunger and satiety by lowering the levels of circulating nutrients. Insulin also may be involved in the long-term regulation of body fat. Hormones released before and after eating also help regulate when we eat meals and how much we eat. The hormone ghrelin, produced by the stomach, is believed to stimulate our desire to eat meals at the usual times. Levels rise an hour or two before mealtime and decrease after a meal is eaten. Peptide YY is a hormone that may help us stop eating because it causes a reduction in appetite and food intake. The gastrointestinal tract releases peptide YY after a meal and the amount released is related to the calorie content of the meal. When we gain weight, our fat cells release the hormone leptin. Increased levels of leptin suppress food intake.

What is a Healthy Diet? The foods that we like are not always the most nutritious, but understanding what makes up a healthy diet allows us to enjoy favorite foods while keeping our diet healthy. A healthy diet provides enough calories to keep your weight within a healthy range; the proper balance and types of carbohydrates, protein, and fat; plenty of water; and sufficient but not excessive amounts of vita-


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Nutrition and eating disorders mins and minerals. A healthy diet is rich in whole grains, fruits, and vegetables; high in fiber; moderate in fat and sodium; and low in saturated fat, cholesterol, and added sugars.

Variety, Balance, and Moderation The principles of variety, balance, and moderation can help you to choose a healthy diet. Choosing a variety of foods is important, because no one food provides everything you need. Even if you are choosing something as healthy as broccoli for dinner, it is important to choose different vegetables on other days or for other meals. Each food provides a unique mix of vitamins, minerals, and phytochemicals. For example, strawberries provide vitamin C but little vitamin A, whereas apricots provide a source of vitamin A, but less vitamin C. If you choose only strawberries, you will get plenty of vitamin C but may be lacking in vitamin A. Balance allows you to include your favorite foods in a healthy diet, even if they are not high in nutrients. Any food can be part of a healthy diet, as long as your overall diet provides enough of all the nutrients you need without excesses. If you eat treats that are low in vitamins and minerals and high in fat and sugar—such as baked goods, snack foods, or sodas—balance these choices by eating more nutrient-dense foods at other times. For example, if your favorite meal is a burger, fries, and a milkshake, go ahead and enjoy it, but balance it with a salad, brown rice, and baked chicken at the next meal. Moderation can help people make sure their diets do not have too many calories, too much salt, sugar, or alcohol, or the wrong types of fat. This helps people maintain a healthy weight and reduce the risk of chronic diseases such as heart disease, high blood pressure, and diabetes.

How Often Should You Eat? There is no ideal number of meals and snacks that a person should eat each day. Both meals and snacks are part of a healthy diet. Young children and growing teens need snacks, because they may


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not be able to consume enough energy during meals to meet their needs. Wisely chosen snacks are important sources of essential nutrients and calories. Occasionally skipping meals is normal, but routinely skipping meals is not recommended. The body burns calories all day, and needs to replace used fuels. This is why breakfast is so important. When you wake up, you have not eaten for 10 to 12 hours or more. You need food to maintain blood glucose and to replenish liver glycogen stores. Students who eat breakfast have been shown to do better in school than those who skip breakfast. In addition, people who eat breakfast are less likely to overeat later in the day. Therefore, people who are trying to lose weight or maintain a healthy weight should eat breakfast.

What Is Abnormal Eating? Food has many meanings, and eating behavior is controlled by many factors. When someone places too much significance on food, eating, and body size and shape, his or her eating patterns may become abnormal. Abnormal eating involves radical reductions of food intake or extreme overeating. Abnormal eating occurs when the emotional aspects of food and eating overpower the role of food as nutrition. It may lead to the development of an eating disorder.

What Are Eating Disorders? Eating disorders are a group of conditions characterized by a pathological concern with body weight and shape. Eating disorders involve a persistent disturbance in eating behavior or other behaviors intended to control weight. These behaviors affect physical health and psychosocial functioning. The term eating disorder is something of a misnomer, because it implies that the primary problem is abnormal eating behavior. In fact, eating disorders are mainly psychological illnesses that involve nutrition-related behaviors and nutritional and physiological complications.


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Genes and Weight Gain Does one of these mice have an eating disorder? You might think that the obese mouse on the left got this way because it has been overeating. That mouse does eat an abnormally large amount, but it is not due to a psychological problem: It is due to a genetic one. The mouse FIGURE 3.2â•‡ Fat cells produce leptin, a has a defect in the gene hormone that helps regulate the amount that controls the produc- of body fat on a person or other animal. tion of leptin. Leptin is a While both of the mice shown here have hormone produced by fat a defective leptin gene, the mouse on cells. If a normal mouse the right has received regular injections weight, the increased size of leptin while the mouse on the left has of its fat cells causes an not received any treatment. increase in the production of leptin. The high levels of leptin signal the mouse to eat less and burn more calories, and thus to lose weight. If the mouse loses weight, the fat cells shrink and leptin levels decrease. The low level of leptin signals the mouse to eat more food and expend fewer calories, and thus gain weight. The mouse on the left cannot make leptin. It always receives the “eat more and expend less” message. Although this mouse has very large fat cells, it keeps eating. Humans also produce leptin, and it helps us maintain our weight. Though it is effective at preventing weight loss, leptin is not as effective in helping us lose it, particularly once we have gained a lot of weight.

fpo figure 3.2


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According to mental health guidelines, there are three categories of eating disorders: anorexia nervosa, bulimia nervosa, and eating disorders not otherwise specified (EDNOS). EDNOS includes eating disorders that do not fit the diagnostic criteria for either anorexia or bulimia. Included in this category is bingeeating disorder, which is more common than either anorexia or bulimia (Table 3.1).

Anorexia Nervosa Anorexia nervosa is characterized by extreme weight loss due to rigid dieting often combined with excessive exercise, stemming from an extreme fear of being fat. Individuals with anorexia spend a great deal of time thinking about food, but they eat

Figure 3.3â•‡ When people with anorexia nervosa look at themselves in the mirror, they typically see themselves as fat even if they are underweight.


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Table 3.1 Characteristics of Different Eating Disorders Eating disorder

Anorexia nervosa

Bulimia nervosa

Binge-eating disorder

Body weight

Below normal (< 85% of recommended)

Usually normal

Usually above normal

Binge eating

Possibly

Yes, at least twice weekly for three months

Yes, at least twice weekly for six months

Purging

Possibly

Yes, at least twice weekly for three months

No

Restricts food intake

Yes

Yes

Yes

Body image

Dissatisfaction with body Distorted body image

Dissatisfaction with body Distorted body image

Dissatisfaction with body

Fear of being fat

Yes

Yes

Not excessive

Self-esteem

Low

Low

Low

Characteristic


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Anorexia nervosa

Bulimia nervosa

Binge-eating disorder

Menstrual abnormaliÂ� ties

Absence of at least three consecutive periods

No

No

Typical age of onset

Preadolescence/ adolescence

Adolescence/ young adults

Adults of all ages

Characteristic

such small amounts that they may literally starve themselves to death. They have an abnormal perception of their bodies, or body image—they see themselves as overweight even when they are dangerously thin (Figure 3.3).

Bulimia Nervosa Individuals with bulimia nervosa, like those with anorexia nervosa, are afraid of weight gain and feel intensely dissatisfied with their bodies. People with this disorder consume large amounts of food over a short period of time in food binges. They then use purging behaviors such as vomiting or taking laxatives to try to rid the body of the excess calories they have eaten. People who have bulimia are typically of normal body weight.

Binge-Eating Disorder Binge-eating disorder is characterized by food binges in which a person eats an excessive amount of food within a discrete period of time. Unlike people with bulimia nervosa, however, people with binge-eating disorder do not purge. These people are typically overweight and are very concerned about how they look.


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The Myths and Realities of Eating Disorders There is a lot of misinformation about eating disorders. Here are some common themes.

Myths

Realities

Only girls get eating disorders.

Although most people with eating disorders are female, eating disorders also occur in males

You can tell someone has an eating disorder by how they look.

Not all people with eating disorders are extremely thin or overweight. Someone of normal weight could have an eating disorder.

Eating disorders are a nutritional problem.

Although people with eating disorders focus on food and eating, this is only a symptom of underlying psychological problems.

People with bulimia always use vomiting as a way to rid themselves of excess calories

Not all bulimics vomit to eliminate excess calories. Some use laxatives, diuretics, exercising, or fasting.

People with anorexia do not binge or purge

Some people with anorexia do binge and purge occasionally.

You cannot die from bulimia.

Bulimia can be life threatening, especially in those who are using laxatives and excessive exercise.

People cannot have more than one eating disorder.

Many people have more than one eating disorder.


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Review Normal eating patterns are varied and flexible. Sometimes we exercise restraint and sometimes we choose to overeat, but in general, we eat when we are hungry or when our appetite is stimulated by outside factors. We choose foods we enjoy, and we usually stop eating when we feel full. Eating disorders develop when people place excessive importance on food, eating behavior, and body size and shape. The three main types of eating disorders are anorexia nervosa, which is characterized by self-starvation; bulimia nervosa, which involves binging and purging behavior; and binge-eating disorder, which is characterized by binging without purging.


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4 eating disorders: Who is affeCted and WhY?

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ating disorders affect more than 10 million Americans, and thousands of people die each year from their complications. Although some groups are at a greater risk than others, eating disorders occur in people of all ages, races, and socioeconomic backgrounds. We do not know what causes eating disorders, but many factors may a play role.

Who deveLops eating disorders? Eating disorders most commonly begin in adolescence, when physical, psychological, and social development is occurring rapidly. They are more common in young women than in young men. Eating disorders occur in all ethnic and economic groups. They are more common in Caucasians and Hispanics than in African Americans and Asian Americans. As the thin ideal of beauty becomes more widely disseminated among minority women,

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EatingDisorders:WhoIsAffectedandWhy? these racial and ethnic differences may diminish. Eating disorders are more prevalent in groups that are concerned with weight and image, such as models, actresses, dancers, and athletes. Scientists estimate that approximately 1% of female adolescents have anorexia nervosa and 4% of college-age women have bulimia nervosa. In North America, where young women are particularly concerned with body size and shape, being thin is associated with beauty, success, intelligence, and vitality. No American girl wants to be plump. Young women find themselves in a world where they are expected to be independent, have a prestigious job, maintain a successful love relationship, bear and nurture children, manage a household, and stay in fashion. These pressures may make them feel as if they cannot control all aspects of their life, so they turn to food intake and body weight as an area in which they can exercise control. These are natural choices, because society tells us that being thin brings success. Males make up about 5% to 15% of people with anorexia or bulimia and 35% of those with binge-eating disorder. The gender difference is likely due to both biological and cultural factors, but most research has focused on cultural factors. The increased risk in women has been hypothesized to be related to women’s subordinate position in society and their socialization to fit specific gender roles. Compared with men, women are less likely to have access to positions of power. They usually earn less money and experience more sexual abuse and harassment. These factors increase the risk of developing eating disorders. Women are encouraged by society to pursue physical attractiveness. In combination with the female beauty ideal of extreme thinness in the United States, this also increases the risk of developing eating disorders. Although most eating disorders occur in people in their teens or early 20s, they also develop in children. As messages about the importance of thinness have become more and more pervasive, eating disorders have begun to appear at younger ages. Eating disorders in people under the age of 13 are considered childhood-

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Nutrition and eating disorders onset eating disorders (see Chapter 9). The causes of these disorders are thought to be the same as the causes among older people. Athletes are at high risk for developing eating disorders. Most at risk are athletes who participate in sports that emphasize appearance and a lean body, such as ballet and other dance, figure skating, gymnastics, running, and swimming, and those in sports with weight classes or in which a low body weight has a performance advantage, such as rowing, horse racing, wrestling, ski jumping, and cycling. Athletes are under extreme pressure to achieve and maintain a body weight that optimizes performance. Failure to meet weight goals can have serious consequences, such as being cut from the team or restricted from competition. This pressure may lead athletes to follow extreme diets to lose or gain weight quickly. Combined with the self-motivation and discipline that characterizes successful athletes, this makes them vulnerable to eating disorders.

What Causes Eating Disorders? We know that eating disorders involve serious disturbances in eating behavior and extreme concern about body size or weight. We also know that eating disorders can be life threatening if treatment is not provided or is not effective. But we do not completely understand what causes eating disorders. Generally, scientists believe they arise from a complex interaction of genetic, psychological, and sociocultural factors (Figure 4.1).

Genetics and Eating Disorders Some of the risk of developing anorexia nervosa and bulimia nervosa appears to be inherited. Eating disorders run in families— they are several times more common among the biological relatives of those with anorexia and bulimia than in the general population. Studies done with twins also suggest that genetics plays a role in the development of both anorexia and bulimia: As much


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figure 4.1 Eating disorders are caused by a combination of genetic, psychological, and sociocultural factors. Medical professionals must address all of these factors if treatment is to lead to an effective recovery.

as half the vulnerability of developing an eating disorder may be inherited. Researchers are just beginning to identify genes that may be involved in the development of eating disorders. Genes contribute to personality traits and other biological characteristics that are related to eating disorders. Scientists have tried to identify

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Nutrition and eating disorders stretches of DNA that are linked to eating disorders. In other words, a piece of DNA that always appears when an eating disorder is present. They can be thought of as genetic markers—if a certain segment of DNA is inherited, genes that contribute to the development of the eating disorder also have been inherited. The search for specific genes that contribute to eating disorders has focused on genes associated with the synthesis and function of neurotransmitters and neurotransmitter receptors that are important in energy balance. Abnormalities in these systems are thought to contribute to the behaviors typical of anorexia, bulimia, and binge-eating disorder. For example, the neurotransmitter serotonin suppresses food intake. Disturbances in serotonin activity have been identified in people with anorexia and bulimia. Dopamine is a neurotransmitter that increases food intake; abnormalities in dopamine are associated with obesity. Variations in these genes contribute to eating disorders, but a single gene is not likely to be the sole cause. Eating disorders are complex diseases that result from the interaction of multiple genes with the environment. Each gene may have a small effect, but when taken together, they can increase risk several-fold. When placed in a high-risk environment, someone who carries such genes will be more likely to develop an eating disorder than someone who does not.

Psychology and Eating Disorders Certain personality characteristics and psychological problems are common among people with eating disorders. In fact, eating disorders frequently co-occur with other psychiatric disorders, such as depression, substance abuse, and anxiety disorders. People with eating disorders tend to have low self-esteem. Selfesteem refers to judgments people make and maintain about themselves—a general attitude of approval or disapproval that indicates whether the person thinks he or she is worthy and capable (Figure 4.2). Self-esteem is shaped by many factors, including how other people respond to you. It can be affected by a history of


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FIGURE 4.2â•‡ Self-esteem is closely tied to eating disorders and those who suffer from low self-esteem may be more vulnerable to acquiring an eating disorder. Brittany Robinson, 15, stands next to tracings of her body done in art therapy class, which is part of her eating disorder treatment. She has had an eating disorder since she was 8 years old.


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Nutrition and eating disorders being teased or ridiculed. Living in a troubled family or having a history of physical or sexual abuse also can influence self-esteem. A high percentage of people with eating disorders have been the victims of rape, incest, molestation, verbal abuse, or neglect. Eating disorders are rooted in the need for self-control. Those who have eating disorders often are perfectionists who set very high standards for themselves and others. In order to be perfect, they strive to control their bodies and their lives. They view everything in life as either a success or a failure. Being fat is seen as failure. Being thin is a success, and being thinner is even better. In spite of their many achievements, people with eating disorders feel inadequate, defective, and worthless. Often, people with eating disorders try to use their relationship with food to gain

The Economics of Weight Loss We have become a society obsessed with weight and dieting. Currently, about 66% of American adults are overweight or obese. As that number gets bigger, so does the business of losing weight. The diet industry is a multibillion-dollar enterprise, the success of which depends upon our failures. At any one time, about 41% of Americans are trying to lose weight. Americans spend nearly $37 billion per year on diet programs, health clubs, books, supplements, and other weight-loss aids. Most Americans think the government requires weight-loss supplements to carry warnings about side effects, but it does not. And most believe that the Food and Drug Administration (FDA) tests weight-loss products for safety, but it does not. The manufacturer is responsible for ensuring the safety of these products. The FDA becomes involved only if the product is found to be unsafe once it is on the shelf. Despite all the concern about weight and the money spent to lose it, the number of overweight people continues to rise, and 95% of all dieters gain back the weight they have lost within five years, thus continuing to feed the diet industry’s financial success.


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control over their lives and boost their self-esteem. They believe that controlling their food intake and weight demonstrates their ability to control other aspects of their lives and to solve other problems (Figure 4.3). Their fixation on food or weight loss and their ability to control food intake and weight help them feel better about themselves. Even if they feel insecure, helpless, or dissatisfied in other areas of life, they may feel fully in control of their food intake, weight, and body size, so they can associate weight control with success. This feeling of control can become addictive.

Sociocultural Factors and Eating Disorders Although genetic and psychological issues may predispose someone to an eating disorder, it is believed that sociocultural factors are important triggers. From television and magazines to advertisements and even toys, society has created a culture of thinness. In modern American society, the ideal body is long, lean, and well muscled. Your body is a presentation of who you are to society. Messages about how we should look are difficult to ignore. They can create pressure to achieve an “ideal” body. Interactions with family members, peer pressure, and the need to fit in can make it seem important to achieve the thin ideal, and may contribute to disturbances in body image and eating behavior. Studies have shown that parental pressure to lose weight, criticism from family members regarding weight, and mothers’ concern about daughters’ body size all correlate with the incidence of adolescent eating disturbances. Many people report that they started bulimic behavior in response to family pressure to lose weight. The influence of peers also is very strong. If a friend thinks it is good to be thin and is always dieting, an adolescent may follow suit. Abnormal eating patterns and practices such as self-induced vomiting for weight control also may be learned from friends. Peer teasing about weight is so significant that it predicts increases in body disturbances and eating problems. In someone who is genetically and psychologically predisposed to eating disorders, attempts to meet the standards set by family,


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FIGURE 4.3â•‡ Daniel Johns, lead singer and guitarist of the Australian band Silverchair, openly admitted his battle with anorexia in a 2004 interview. Before receiving treatment, the 5-foot 10-inch singer’s weight dipped to 110 pounds (50 kg) and he contemplated suicide.


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friends, and society may trigger an eating disorder. For example, a young woman who is a perfectionist may try hard to conform to the cultural ideal of the perfect body. Along the way, she may develop an abnormal body image, or view of her own body. Body image is an important component of self-esteem, especially for women, because we live in a culture that places a great deal of emphasis on the appearance of women’s bodies. A poor body image is linked to low self-esteem. Even if a woman with an eating disorder achieves a body weight comparable to that of a fashion model, she may continue to see herself as fat and strive to lose weight.

Do You Know Someone with an Eating Disorder? Although these disorders are psychological in nature, the physical consequences are severe. People with eating disorders usually do not recover by themselves. Even if they get better on their own, the disorder is likely to return. You cannot provide medical or psychological treatment to a friend or relative with an eating disorder, but that doesn’t mean there is nothing you can do. If you suspect that someone you care about has an eating disorder, try to get him or her to seek professional help. You can do this by alerting a parent, teacher, coach, religious leader, school nurse, or other trusted adult about your concerns, or you can confront your friend or relative directly and express your concern. When confronting someone with an eating disorder, you should be prepared for all possible reactions. Some may be relieved that someone is concerned and is willing to help, but more likely, he or she will be upset, defensive, or angry. Your friend or relative is likely to be embarrassed and ashamed. People with eating disorders typically hide their behaviors, so it may be traumatic for them to learn that someone has discovered their secret. The first reaction is often denial: There is no problem. People with eating disorders find protection, comfort, and empowerment through the disorder. They may be reluctant to give up these perceived


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Pica: Dining on Dirt People do actually eat dirt! Pica is the abnormal craving for and ingestion of nonfood substances, including dirt, that have little or no nutritional value. The word “pica” comes from the Latin word for magpie, a bird known for eating almost anything. People with pica commonly consume clay, dirt, plaster, chalk, cornstarch, laundry starch, coffee grounds, burnt match heads, and ashes. Unlike anorexia and bulimia, this strange eating disorder is not linked to body image. The cause of pica is unknown, but it is thought to be due to a mix of cultural, socioeconomic, psychological, and biological factors. It is most common in young children and pregnant women. Pica occurs throughout the world; it is widespread in western Kenya, southern Africa, and India. In some societies, eating these types of substances is culturally acceptable, and not considered abnormal. For example, in some rural areas of the southern United States, eating clay is a traditional remedy for nausea that occurs early in pregnancy. Pica can have serious health consequences. Consuming large amounts of nonfood substances may mean that people are eating fewer nutrient-dense foods. It also can inhibit nutrient absorption, increase the risk of consuming toxins, and cause intestinal problems. Complications include iron-deficiency anemia, lead poisoning, parasitic infestations, and gastrointestinal complications: constipation, ulcerations, perforations, and obstructions.

benefits. They may view seeking treatment as an admission that they are inadequate, and as a loss of control. They also may fear the weight gain that would accompany treatment. When you approach someone about a suspected eating disorder, be firm but supportive and caring. Back up your statements with examples of things you have seen that make you believe there is a problem. If you have a lot of evidence, it will be more difficult


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for the person to deny. When trying to persuade the person to get help, talk about his or her health, relationships, and mood, and not appearance or weight. Unless the illness is viewed as an immediate threat to a person’s life, adults (those 18 years of age or older) must make their own decision as to whether they will get help. Those under 18 can be forced into treatment by a parent or guardian. However, help is only effective if it is desired. People with eating disorders are likely to refuse help at first. When you approach someone about an eating disorder, make it clear that you are not trying to force him or her to do anything. Continued encouragement can help some people decide to seek professional help.

How Can Eating Disorders Be Prevented? Recognizing the factors that increase the risk of eating disorders can help prevent a person from developing an eating disorder. These include excessive concerns about body weight, having friends who are preoccupied with weight, teasing from peers about weight and disordered eating, the presence of early eating disorder symptoms, and problems within one’s family. There is an association between parental criticism and children’s weight preoccupation. Dieting also increases risk. Girls and women who diet are 18 times more likely to develop an eating disorder than those who don’t diet. People who have a mother, sister, or friend who diets are also at increased risk. Exposure to media pressure to be thin also is associated with the development of eating disorders. If people at risk are identified, intervention may prevent the development of a full-blown disorder. Parents play an important role because they can arrange an evaluation with a physician and a mental health specialist when the first signs of an eating disorder are discovered. Interventions to reduce the incidence of eating disorders within the population should target the elimination of weightrelated teasing and criticism from peers and family members.


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NuTRITIONANDEATINGDISORDERS Another important target is the media. If the unrealistically thin body ideal presented by the media could be altered, the incidence of eating disorders would likely decrease. Another approach is education. Lectures given by people who are recovering from eating disorders and educational programs offered through schools and communities can help people identify friends and family members who are at risk and persuade those with early symptoms to seek help. Eating disorders are easier to prevent than to cure.

revieW Eating disorders are most common among adolescent women. Men are affected at a much lower rate. All ethnic groups are affected to some extent. Athletes are at particular risk because they are under pressure to maintain a body weight that optimizes their performance. Eating disorders are caused by a complex interaction of genetic, psychological, and sociocultural factors. Genes determine the personality traits and other biological factors that predispose people to eating disorders. Psychological problems such as low self-esteem, depression, insecurity, and anxiety further increase risk. Sociocultural factors that reinforce the view of the perfect body as a thin body act as a trigger for the development of an abnormal body image and eating disorders. Pressure from parents or other family members can also influence body image. If you have a friend or family member who you suspect has an eating disorder, you should be caring and supportive while encouraging the person to seek professional help. Preventing eating disorders depends on identifying risk factors and eliminating them, or identifying people who are at risk and targeting them for early intervention.

5 BodY iMage

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ody image can be thought of as the picture of your body that you form in your mind. It is how you perceive and imagine yourself. When you look in the mirror, you compare what you see with what you think you should look like. Your body image is affected by the ideals of your culture and society. How you compare yourself to this ideal influences how you feel about your body and how satisfied you are with it.

BodY iMage, historY, and CuLture What is viewed as an ideal body has changed throughout history. It also differs across cultures. Paleontological drawings and figurines show women with large breasts and swollen abdomens. Prehistoric Greek, Babylonian, and Egyptian sculptures represent women with large, pregnant abdomens and heavy hips and thighs (Figure 5.1). Throughout human history, food shortage has been a

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FIGURE 5.1â•‡ In primitive cultures, the ideal female form was very different from the image we see in fashion magazines today. Even in modern times, in places where food is not readily available, the ideal body type is much plumper than that promoted in North America. This prehistoric European limestone figurine depicts the ideal female body type during that time.


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constant concern and obesity has been almost nonexistent. As a result, large body size was admired as a symbol of health, prestige, and prosperity. Today, cultures in which there is a real risk of starvation continue to view a plump physique with positive associations. Big women are considered sexually attractive and beautiful, and plumpness is seen as a sign of fertility, strength, and survival. For example, among the Kipsigis of Kenya, a fatter bride commands a higher dowry. In the Havasupai nation of the American Southwest, fat legs—and, to a lesser extent, fat arms— are considered essential to beauty. Among the Amhara people of Ethiopia, thin hips are undesirable and are referred to by the derogatory term dog hips (Figure 5.2). A crosscultural survey found that 81% of societies viewed plumpness or “being filled out” as desirable. Cultural ideals about body size are linked to body image and the incidence of eating disorders. Eating disorders occur in societies in which food is abundant and the body FIGURE 5.2â•‡ In many cultures where ideal is thin. They do not food is scarce, a plumper, rounder occur where food is scarce physique is a desirable trait in women. and people have to worry Members of the Ethiopian Amhara tribe, about where their next for instance, prefer women to have meal is coming from. In rounder hips rather than slim ones. the United States today,


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Nutrition and eating disorders food is plentiful. We are the fattest society in history, yet we yearn to be thin, whereas in cultures where food is scarce and obesity is rare, young women may go to great lengths to gain weight to be attractive. For example, there is a lower incidence of eating disorders among women living in non-Western, nonindustrialized nations and among certain ethnic minorities in the United States. Immigrants to Western countries are more likely to develop eating disorders than those who remain in their country of origin. As economic changes occur in non-Western societies, the incidence of eating disorders is increasing. They are becoming common clinical problems in young women in high-income Asian societies, such as Japan, Hong Kong, Singapore, Taiwan, and the Republic of Korea. They also have appeared in major cities in low-income Asian countries such as China, Malaysia, the Philippines, and Indonesia. Eating disorders have even been identified in unexpected locations such as India and Africa.

The Changing American Body Ideal The thin fashion model currently viewed as beautiful in modern American society was not always the ideal. The image of the

The Models We Model Ourselves After Note these facts about female fashion models: ●âŠ‘ ●âŠ‘

●âŠ‘

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Fashion models are thinner than 98% of American women. The average American woman is 5’4” and weighs 140 pounds. The average fashion model is 5’10” and weighs 110 pounds. The average weight of a model is 23% lower than the weight of an average woman; 40 years ago, this difference was 8%. Medically, the typical fashion model is underweight: She is in a weight range below what is recommended for optimal health.


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perfect body has changed over the last century. Many of these changes have followed other trends in society. In the nineteenth and early twentieth centuries, a small waist and full hips were fashionable. Corsets were worn to make the waist small, and full skirts and bustles were used to make hips look full. This clothing was not comfortable, but it hid flaws and helped make a woman’s body better fit the ideal. In order to get the ideal look, women had to change their clothes, not their bodies. In the 1920s, some major changes occurred in women’s lives and in their fashions. They won the right to vote, and it became more common for them to work outside the home. As women moved into the male-dominated workforce, having a less feminine body allowed them to fit in and be taken more seriously. A plump, full figure was associated with being maternal, tied to home and family. Thinness was equated with being sexy, free, and available, and this association helped launch the popularity of the flapper look. The flapper look featured short hair and short skirts. Flapper styles emphasized small breasts, a slim waist, and narrow hips. Corsets were not worn under the short, loose flapper dresses (Figure 5.3). Now, to have the “in” look, women needed to change their bodies—not just tighten their corsets. Two other things occurred in the 1920s that had significant impacts on how women viewed their bodies. One was an increase in the availability and popularity of ready-made clothes. Before this time, clothes were typically made at home or by a family seamstress, so clothing size was not an issue. The dress was made to fit the body. Mass-production of clothes meant that dresses had to have standard sizes. Now the body had to fit the dress. This gave women a numerical way to compare themselves with others. Women who needed dresses at the large end of the standard sizing system knew they were bigger than the norm. The 1920s also was the decade when the Miss America Pageant was founded (Figure 5.4). For the first time, a large number of young women nationwide made efforts to lower their weight by restricting their food intake and exercising. Dieting for weight loss became popular.


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FIGURE 5.3â•‡ The fashion style known as the flapper look (right) freed women’s bodies from the discomfort of the corset (left) and led to changes in what was perceived as a desirable body shape. While a corset and bustle could create a large bust, a thin waist, and round hips, the look of the flapper dress depended on the wearer’s natural body shape.

The focus on thinness was less intense in the 1930s. During this time, the Great Depression shifted attention away from dieting and toward having the money to get enough to eat. Also, an increase in immigration brought new people to America. Many of them had suffered hunger throughout their lives, and wanted their children to be plump rather than thin. They saw plumpness as a symbol of their achievement in the New World. In this immigrant culture, fat was a symbol of success and freedom from want. Worries about the lung disease tuberculosis also made thinness


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undesirable to many. One of the first symptoms of tuberculosis was weight loss, so a child who stayed fat was considered healthy. In the early 1940s, the United States was focused more on World War II and less on body size. In the 1940s and 1950s, actresses such as Jayne Mansfield, Jane Russell, and Marilyn Monroe, known for their curves and large breasts, were the ideal. Rather than focusing on thinness, women aspired to have breasts like Marilyn Monroe (Figure 5.5). In the 1950s, large, lifted, pointy breasts were the beauty standard. Bras began to be mass produced and magazines began publishing exercises to increase bust size. The thinness message, however, had not gone away. Seventeen

FIGURE 5.4â•‡ After the Miss America competition was created in the 1921, beauty pageants became popular among young women. Contestants were judged based on appearance in different outfits, including swimsuits, as seen in this photo of the 1937 Miss America contestants. These pageants helped fuel the dieting trends of the 1920s and 1930s.


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FIGURE 5.5â•‡ The bodies people see on the pages of magazines dictate what they view as the body ideal. In the 1950s, the curvaceous figure of Marilyn Monroe was seen as the perfect body.


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magazine, which is targeted to teens, began publication in 1944; within four years, it was publishing articles on dieting and the importance of looking attractive. The physical standards for women in the 1960s were reflected by the immense popularity of Barbie, a doll introduced in 1959. Barbie’s improbable figure—large chest and pinched waist, with hips somewhere in between—was an exaggerated version of the ideal body type of the era. Thin actresses such as Audrey Hepburn were favorites, and thin fashion models began to gain in popularity. The person who did the most to popularize the waiflike look was British fashion model Twiggy. Twiggy was 5 feet, 7 inches tall and weighed just 91 pounds. Her arrival to America in the 1960s triggered a downward shift in average sizes for fashion models. As teenage girls tried to achieve the “Twiggy look,” dieting increased in popularity. Weight Watchers®, an international organization designed to promote weight management, was founded in 1963. It recruited 500,000 members during its first year and grossed $5.5 million in revenue. In the 1970s, although thin was still in, being fit and toned also became popular. This trend continued into the 1980s and 1990s; exercise videotapes and health and fitness clubs took over the job of promoting fitness. Supermodel Kate Moss became the new Twiggy—revered for her thin frame—as she was featured in numerous fashion magazines and advertisements, most notably for Calvin Klein (Figure 5.6) Today, most models are 5 feet 8 inches or taller and weigh between 108 and 125 pounds. This weight-to-height would put them in the underweight category, according to BMI.

The Media Affect Body Image In American society, messages about what the perfect body looks like are constantly delivered by the mass media. Television, movies, magazines, the Internet, and advertisements show us what society views as a perfect body—the ideal we should strive for. The


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FIGURE 5.6â•‡ Although body ideals vary over time, in recent decades, thinness has become more important in U.S. society. Model Kate Moss (left), shown here next to model Naomi Campbell, is known for ushering in the “waif look” in 1993.


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tall, dark, muscular man gets the girl; the thin, athletic woman gets her man. The most successful movie stars are slim and gorgeous. Thin models show us how the latest fashions should look. All of this adds up to a standard that is very difficult to meet, a standard that is contributing to disturbances in body image and eating behavior. As the body dimensions of female models, actresses, and other cultural icons have become thinner over the last several decades, the incidence of eating disorders has increased. The association between mass media and body image and eating disorders has been demonstrated on the Pacific island of Fiji. Fiji had no thin-ideal body images until the introduction of Western media. Once that happened, body image changed and eating disturbances became apparent.

Your Body Image Body image is an important determinant of self-esteem. The goal for everyone is to maintain a healthy body image. This means that the mental image you have of your body is accurate and positive. Body image can change with age, mood, environment, and life experiences.

How Body Image Develops How we feel about our bodies is affected by our experiences, as well as changes in our bodies. A child’s body image changes to match changes in body structure that occur as he or she grows. The child absorbs media messages about body size and shape and the attitudes of others toward his or her body and its parts. He or she may develop a body image that is pleasing and satisfying, or one that is unpleasant and shameful. The attitudes of parents have a particularly strong effect on how a child views his or her body. Body image problems are common during the teen years. As teens go through puberty, they experience significant physical changes in their bodies. Adolescent boys grow taller, muscle mass increases, body and facial hair appears, and the voice deepens. Adolescent girls grow taller, put on weight, and develop breasts.


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A Timeline of Weight Consciousness 1900: At about 200 pounds, stage actress Lillian Russell is considered a beauty icon. 1920s: Fashion designer Paul Poiret develops the flapper look. Home scales are introduced. Ready-made clothes produced in standard sizes become popular. 1921: The first Miss America beauty pageant is held in Atlantic City, N.J. 1950s: Marilyn Monroe epitomizes shifting beauty standards, with a change in focus from weight to large breasts. 1959: Phentermine (Phen), an appetite suppressant that increases the body’s metabolism, is approved by the Food and Drug Administration (FDA) to help speed weight loss. 1960s: Twiggy is the leading fashion model. Dieting becomes popular for the masses. 1977: Liquid-protein diets are banned temporarily after three deaths are reported during the 1970s. 1981: Actress Jane Fonda’s workout book is an instant bestseller and continues the fitness craze of the 1970s. 1980s: Liposuction is imported from France and approved in the United States. Twenty deaths are reported during its first six years in America. 1983: Singer Karen Carpenter of The Carpenters dies at age 32 from anorexia nervosa, bringing widespread attention to eating disorders. 1995: The U.S. Centers for Disease Control and Prevention (CDC) estimates that 5 million to 10 million women have eating disorders. 1997: Diet drugs phentermine and fenfluramine (Phen-fen) are voluntarily taken off the market after being associated with heart valve damage. Tens of thousands of users are at risk. 2000: Despite the nation’s obsession with diet and exercise, obesity is on the rise. According to the CDC, obesity affects nearly one in five Americans. 2009: One in three American adults are now obese, and the incidence of eating disorders continues to rise.


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A girl’s hips and waist become more defined, and she begins to menstruate. These changes occur at different times in different people, because everyone develops at his or her own rate. The rate at which teens develop becomes tied to their emotions and how they feel about themselves and their bodies. Some become more self-conscious about their bodies, compared with their peers. The teen years also bring new social pressures. Insecurity is common as teens struggle to feel socially accepted. Concern about physical development and fitting in with peers puts teens at risk of developing a poor body image and an eating disorder. Developing and maintaining a healthy body image involves paying attention to your body by practicing good nutrition and including exercise in your lifestyle. It also means accepting and appreciating your body as it is. Having a healthy body image means being realistic about your size based on your family history and realizing that weight and body shape can change continuously, especially during the adolescent years.

Unhealthy Body Image Problems with body image involve two patterns—dissatisfaction and distortion. Body image dissatisfaction means that you don’t like your body or some part of your body. You may feel ashamed or self-conscious. Body image distortion means that you are unable to judge the size of your body, or that you perceive parts of your body as being different from how they really are. Both body image dissatisfaction and distortion are more common among females than males, with almost twice as many females being dissatisfied with their bodies than males. In women, body image dissatisfaction typically involves feeling that they are too fat, whereas most men are unhappy with their bodies because they believe they are too thin and not muscular enough. Problems with body image decrease self-esteem and increase the risk of developing eating disorders. For example, body image distortion is characteristic of anorexia. People with this disorder may see themselves as fat even if they are not, insisting that their emaciated bodies are not too thin, but rather just right, or even


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Dos and Don’ts of a Healthy Body Image DO Accept that bodies come in many shapes and sizes. ●âŠ‘ Recognize your positive qualities. ●âŠ‘ Remember that you can be your worst critic. ●âŠ‘ Explore your internal self, emotionally and spiritually, as well as your external appearance. ●âŠ‘ Spend your time and energy enjoying the positive things in your life. ●âŠ‘ Be aware of your own weight prejudice. Explore how those feelings may affect your self-esteem. DON’T ●âŠ‘ Let your body define who or what you are. ●âŠ‘ Judge others on the basis of appearance, body size, or shape. ●âŠ‘ Forget that society changes its ideals of beauty over time. ●âŠ‘ Forget that you are not alone in your pursuit of self-acceptance. ●âŠ‘ Be afraid to enjoy life. ●âŠ‘

slightly plump. People with eating disorders may be convinced that only other people are attractive and that their body size or shape is a sign of personal failure. They equate being thin not only with beauty, but also with vitality, success, and intelligence. An unhealthy body image can affect not only self esteem, but also eating habits and health. Because changes in the amount of food people eat can change their body size and shape, people who are unhappy with their bodies may use food and eating patterns as a way to change their bodies to fit a particular image. For some, a weight-loss diet that causes them to slim down makes them happier with their bodies, but for others, no amount of dieting will help them feel good about themselves.


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Body Image

81

Review Body image is how you perceive and imagine your body. What is viewed as the ideal body has changed throughout history and differs among cultures. In most developing nations, the female ideal is plumper than it is in Western industrialized societies. In the United States, what is viewed as a perfect body has changed over the last century. Today, the ideal female image is one that is unrealistically thin. This image is seen on television, in magazines, and in the movies. Comparing themselves with this ideal can cause many women to see themselves as too fat and to develop an unhealthy body image. Having a healthy body image means you are accepting and appreciative of your body and realistic about your body size. The most common body image problems include dissatisfaction with your body and body image distortion, which is the inability to see yourself as you really are. Body image problems can affect eating behavior and increase the risk of eating disorders.


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6 a heaLthY BodY Weight

W

hat we view as the perfect body is often more dependent on what society tells us is beautiful than what medicine tells us is healthy. As a result, many American women strive to attain a body weight that has little relation to what is actually healthy. We know that being too fat is not healthy, but we rarely think about the fact that being too thin also carries health risks.

What is a heaLthY BodY Weight? A healthy body weight is the weight at which the risk of illness and death is lowest. It is the weight that is associated with the greatest health and longevity. A healthy body weight for you depends on how much you weigh relative to your height. It also depends on how much body fat you have and where the fat is on your body. Traditionally, body weight has been assessed by evaluating weight for height. The current standard is body mass index, or BMi. BMI is determined by using a chart or mathematical equation (Figure 6.1).

82

AHealthyBodyWeight

83

figure 6.1 To T determine your BMI range, locate your weight at the top of the scale and your height on the left-hand side. Draw a line down from your weight number and to the right of your height number. The point where the two lines meet within the graph indicates your BMI.

84

Nutrition and eating disorders For adults, a healthy BMI is between 18.5 and 24.9 kg/m2. Those with BMIs in this range have the lowest health risks. Those with BMIs above or below this range have higher risks of illness and early death. Underweight for adults is defined as a BMI of less than 18.5 kg/m2, overweight is defined as a BMI of 25 to 29.9 kg/m2, and obese is a BMI of 30 kg/m2 or greater. A BMI of 40 or higher is classified as extreme or morbid obesity. The average BMI of U.S. adults is 28 kg/m2. BMI also can be used to assess healthy weight in teens and children over age 2. However, rather than individual numbers, healthy BMI is defined by using growth charts. Growth charts consist of a series of percentile curves that represent the distribution of body measurements in U.S. children from birth to age 20. They were developed as a clinical tool for health professionals to determine if a child’s growth is appropriate. The percentile indicates where the child or teen’s growth falls in relation to population standards. For example, if a 14-year-old boy is at the 40th percentile for BMI, 39% of boys his age have a lower BMI and 60% have a higher BMI. A healthy BMI for a child or teen is one that falls from the 5th to just below the 85th percentile on the BMIfor-age growth charts. A child is considered overweight when his or her BMI is greater than or equal to the 85th percentile but less than the 95th percentile. A child is considered obese when BMI falls at or above the 95th percentile. Underweight children have a BMI of less than the 5th percentile. (The BMI-for-age growth chart for boys ages 2 to 20 is shown in Figure 6.2; a similar chart for girls is in Appendix B.) BMI is preferred over a standard weight for height determination because it correlates better with the amount of body fat. Despite this, BMI is not a perfect tool for evaluating the health risk associated with obesity. An individual with a BMI in the overweight range who consumes a healthy diet and exercises regularly may be more fit than someone with a BMI in the healthy range who is sedentary and eats a poor diet. In addition, a person may have a high BMI because he or she has a high body weight


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A Healthy Body Weight

85

due to more muscle mass, rather than excess body fat. For example, a weight lifter or body builder with a large amount of muscle mass will have a high BMI but may have very little body fat, and therefore have a low risk for the diseases associated with obesity.

What is a Healthy Body Composition? The human body is made up of lean tissue and fat tissue. The lean tissue, or lean body mass, includes muscle, bone, fluids, and internal organs. The fat tissue is the body fat that we store. The amount of body fat you have relative to lean body mass, or your body composition, is a more important determinant of your health risks than your body weight. Having too much body fat is associated with an increased risk of many chronic health problems, such as heart disease, cancer, and diabetes. The percentage of body weight that is due to fat is affected by age and gender. At birth, the typical infant has about 12% body fat, and this percentage increases during the first year of life. During childhood, muscle mass increases and body fat decreases, so percent body fat declines. During adolescence, body weight increases. Females gain proportionately more fat and males gain more muscle mass. As adults, women continue to have more stored body fat than men. A healthy level of body fat for a young adult female is between 21% and 32% of total weight; for young adult males, it is between 8% and 19%. As people age, even if body weight remains the same, lean body mass decreases and body fat increases. Some of this change may be prevented by physical activity. Too much body fat is unhealthy, but the amount that is desirable varies greatly and depends on the individual. For example, people who live and work in cold climates may benefit from extra body fat to prevent heat loss. The amount of body fat may affect the performance of certain types of athletes. A professional football fullback may need to carry extra fat to excel in his sport,


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86


A Healthy Body Weight

87

whereas a distance runner will be faster if his or her percentage of body fat is lower. All athletes need enough fat to provide essential functions such as insulating the body, supplying energy reserves, and supporting normal hormonal activity, but not so much that it adds bulk. Some male athletes may perform best when their body fat is only 5% to 10%, and some female athletes when body fat is 15% to 20%. In a person with anorexia nervosa, the body fat percentage can drop so low that body temperature cannot be maintained, there is no cushioning to protect internal organs and other tissues, and hormonal activity becomes abnormal.

Measuring Body Fat Body fat can be measured in a number of ways. Some methods can be used in a doctor’s office, at a health club, or even at home. Currently, the most popular method is bioelectric impedance analysis. It can assess body fat by measuring the flow of a small, painless electric current sent through the body in one of three ways: Electrodes attached to a hand and a foot A meter that the subject holds with both hands ●âŠ‘ A scale on which the person stands ●âŠ‘ ●âŠ‘

Body fluids conduct electricity and body fat offers resistance, or impedance, to current flow. A given amount of electrical current enters the body through one electrode, and the amount emerging at the other electrode is measured. The more body fat the person has, the more impedance there is, and the less current emerges. The measure of impedance can be used to (opposite page) FIGURE 6.2â•‡ Body weight in children and teens is assessed by calculating BMI and plotting it on a BMI-for-age growth chart to determine the percentile. The percentile classifies their weight as healthy, underweight, overweight, or obese.


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Stored Fat Keeps You Going Even people who are at a healthy body weight store a lot of energy in body fat. A man who has a BMI of 22 and a body fat of 20%, both in the healthy range, stores about 115,000 calories in his adipose (fat) tissue. To expend this amount of energy, he would need to do aerobics for 9 ½ days without stopping.

calculate the amount of body fat. Bioelectric impedance measurements are fast, easy, and painless. However, they can be inaccurate if the amount of body water is higher or lower than typical. For example, in someone who has been sweating heavily, the estimate of percent body fat obtained using bioelectric impedance will be artificially high. Measures of skinfold thickness also can provide accurate estimates of body fat if performed by a trained technician. These assess the thickness of the layer of fat under the skin, called subcutaneous fat, and assume it is representative of total body fat. Measurements are done by pinching the skin and fat layer that lies over the muscles at specified locations and using a caliper to determine the thickness (Figure 6.3). Mathematical equations are used to estimate body fat percentage from these measurements. Underwater weighing compares a person’s weight on land with his or her weight under water. The difference between these measurements can be used to determine body volume and body density. Body density can be used to estimate body fat because fat is less dense than lean tissue, so someone with a lower body density has a higher percentage of body fat than someone with a higher body density. Although this method is accurate, it is not practical for many people, such as small children or frail adults. A newer method for estimating body composition measures air displacement rather than water displacement.


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89

a Healthy Body Weight

are you an apple or a pear? The location of the fat in a person’s body is important in determining the risks associated with excess body fat. Fat around the hips and thighs is generally subcutaneous fat. This fat carries less risk than fat deposited around the organs in the abdominal region, which is called visceral fat. An increase in visceral fat is associated with a higher incidence of heart disease, high blood pressure, stroke, diabetes, and breast cancer. People who tend to

FiguRe 6.3 Body fat is measured using an instrument called a skinfold caliper (left). This cross-section of an arm (right) illustrates the location of the fat under the skin and how this fat layer is measured. Skinfold thickness is measured at one or more locations; the most common sites for skinfold measurements are the umbilicus (near the belly button), triceps (the area over muscles on the back of the upper arm) and subscapular (just below the shoulder blade).


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90


Who’s the Fattest? Did you ever flop down in a chair after a big meal, feeling like a beached whale? Whales are the largest mammals and have an enormous amount of body fat. However, if you express a whale’s body fat as a percent of its body weight, it is much leaner than most humans. The largest animal on earth, the blue whale, weighs about 264,000 pounds (120,000 kg). Blue whales have a layer of subcutaneous fat that is 2.4 in to 3.2 inches (6 cm to 8 cm) thick. This represents about 530 cubic feet (15 m3) of fat. That’s enough to fill your bedroom from floor to ceiling! But a blue whale is only about 12% fat, about the same as a lean male athlete. When feeling fat, perhaps you should say you feel like a ringed seal or a lab rat! At weaning, a ringed seal pup is about 50% body fat. An adult mouse of the genetically obese Ob strain carries about 70% fat. This is much higher than the 20% to 30% body fat found in an average human. But when it comes to records, the humans have it. When the fattest man on record died in 1983 at age 42, he weighed 1,397 pounds (634 kg) and was estimated to be 80% fat.

deposit fat in their hips and thighs have been described as pear shaped, whereas those who deposit it in their abdomens have been described as apple shaped (Figure 6.4). Where body fat is deposited is determined primarily by genetics, but gender, age, and lifestyle also are influences. Visceral fat storage is more common in men than women. After menopause, though, visceral fat increases in women. African-American women store less visceral fat even though their incidence of obesity is 50% higher than that of Caucasian women. Tobacco use, stress, and alcohol consumption increase visceral fat deposition. Exercise reduces the amount of visceral fat. Figuring out the relative amounts of visceral and subcutaneous fat requires complex imaging methods. An easier way to


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91

assess whether a person carries too much visceral fat is to measure his or her waist circumference. In a person with a high BMI, a large waist circumference indicates a greater amount of visceral fat, and thus increased health risks. For males, a BMI of 25 kg/m2 to 34.9 kg/m2 and a waist circumference greater than 40 inches

figure 6.4 Overweight people who are “apple-shaped” (left) eft deposit eft) fat in the abdominal region, around body organs, and are at a greater risk of heart disease and diabetes. People who are “pear-shaped” (right right) right ght) carry their fat under the skin in the hips and thighs, which presents fewer health risks.


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92

Nutrition and eating disorders is associated with increased risk. For females in this BMI range, waist circumference of greater than 35 inches increases the risks associated with being overweight (Table 6.1).

The Risks of Being Overweight The guidelines for a healthy BMI, body fat percentage, and waist circumference were developed by evaluating the body weights and compositions that are associated with the lowest incidence of disease and death. As BMI and the amount of body fat rise above the

Table 6.1 BMI, Waist Circumference, and Disease Risk Disease Risk† Men, waist ≤ 40 inches, Women, waist ≤ 35 inches

Men, waist > 40 inches, Women, waist > 35 inches

25.0 to 29.9

Increased

High

Obesity (class I)

30.0 to 34.9

High

Very high

Obesity (class II)

35.0 to 39.9

Very high

Very high

Extreme or morbid obesity (class III)

≥40

Extremely high

Extremely high

inches

BMI (kg/m2)*

Underweight

70 yrs

900

90

15

15

120

9–13 yrs

600

45

5

11

60

14–18 yrs

700

65

5

15

75

19–30 yrs

700

75

5

15

90

31–50 yrs

700

75

5

15

90

51–70 yrs

700

75

10

15

90

>70 yrs

700

75

15

15

90

≤18 yrs

750

80

5

15

75

19–30 yrs

770

85

5

15

90

31–50 yrs

770

85

5

15

90

≤18 yrs

1,200

115

5

19

75

19–30 yrs

1,300

120

5

19

90

31–50 yrs

1,300

120

5

19

90

Infants

Children

Males

Females

Pregnancy

Lactation


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Appendix A

157

Recommended Intakes of Vitamins for Various Age Groups Life Stage

Thiamin (mg/day)

Riboflavin (mg/day)

Niacin (mg/day)

Vit B 6 (mg/day)

Folate (μg/day)

0–6 mo

0.2

0.3

2

0.1

65

7–12 mo

0.3

0.4

4

0.3

80

1–3 yrs

0.5

0.5

6

0.5

150

4–8 yrs

0.6

0.6

8

0.6

200

0.9

0.9

12

1.0

300

Infants

Children

Males 9–13 yrs 14–18 yrs

1.2

1.3

16

1.3

400

19–30 yrs

1.2

1.3

16

1.3

400

31–50 yrs

1.2

1.3

16

1.3

400

51–70 yrs

1.2

1.3

16

1.7

400

>70 yrs

1.2

1.3

16

1.7

400

9–13 yrs

0.9

0.9

12

1.0

300

14–18 yrs

1.0

1.0

14

1.2

400

Females

19–30 yrs

1.1

1.1

14

1.3

400

31–50 yrs

1.1

1.1

14

1.3

400

51–70 yrs

1.1

1.1

14

1.5

400

>70 yrs

1.1

1.1

14

1.5

400

1.4

1.4

18

1.9

600

Pregnancy ≤18 yrs 19–30 yrs

1.4

1.4

18

1.9

600

31–50 yrs

1.4

1.4

18

1.9

600

1.4

1.6

17

2.0

500

Lactation ≤18 yrs 19–30 yrs

1.4

1.6

17

2.0

500

31–50 yrs

1.4

1.6

17

2.0

500

(continues)


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158


Recommended Intakes of Vitamins for Various Age Groups (continued) Life Stage

Vit B12 (μg/day)

Pantothenic Acid (mg/day)

Biotin Group (μg/day)

Choline* (mg/day)

0–6 mo

0.4

1.7

5

125

7–12 mo

0.5

1.8

6

150

Infants

Children 1–3 yrs

0.9

2

8

200

4–8 yrs

1.2

3

12

250

1.8

4

20

375

Males 9–13 yrs 14–18 yrs

2.4

5

25

550

19–30 yrs

2.4

5

30

550

31–50 yrs

2.4

5

30

550

51–70 yrs

2.4

5

30

550

>70 yrs

2.4

5

30

550

9–13 yrs

1.8

4

20

375

14–18 yrs

2.4

5

25

400

Females

19–30 yrs

2.4

5

30

425

31–50 yrs

2.4

5

30

425

51–70 yrs

2.4

5

30

425

>70 yrs

2.4

5

30

425

≤18 yrs

2.6

6

30

450

19–30 yrs

2.6

6

30

450

31–50 yrs

2.6

6

30

450

2.8

7

35

550

Pregnancy

Lactation ≤18 yrs 19–30 yrs

2.8

7

35

550

31–50 yrs

2.8

7

35

550

Note: This table presents Recommended Dietary Allowances (RDAs) in bold type and Adequate Intakes (AIs) in ordinary type. * Not yet classified as a vitamin Source: Adapted from Dietary Reference Intake Tables: The Complete Set. Institute of Medicine, National Academy of Sciences. Available online at www.nap.edu.


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Appendix A

159

Recommended Intakes of Selected Minerals for Various Age Groups Life Stage

Calcium (mg/day)

Chromium (μg/day)

Copper (μg/day)

Fluroide (mg/day)

Iodine (μg/day)

0 – 6 mo

210

0.2

200

0.01

110

7–12 mo

270

5.5

220

0.5

130

1–3 yrs

500

11

340

0.7

90

4 – 8 yrs

800

15

440

1

90

9 –13 yrs

1,300

25

700

2

120

14 –18 yrs

1,300

35

890

3

150

19–30 yrs

1,000

35

900

4

150

Infants

Children

Males

31–50 yrs

1,000

35

900

4

150

51–70 yrs

1,200

30

900

4

150

>70 yrs

1,200

30

900

4

150

9–13 yrs

1,300

21

700

2

120

14 –18 yrs

1,300

24

890

3

150

19–30 yrs

1,000

25

900

3

150

31–50 yrs

1,000

25

900

3

150

51–70 yrs

1,200

20

900

3

150

>70 yrs

1,200

20

900

3

150

1,300

29

1,000

3

220

19–30 yrs

1,000

30

1,000

3

220

31–50 yrs

1,000

30

1,000

3

220

1,300

44

1,300

3

290

19–30 yrs

1,000

45

1,300

3

290

31–50 yrs

1,000

45

1,300

3

290

Females

Pregnancy ≤18 yrs

Lactation ≤18 yrs

(continues)


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160


Recommended Intakes of Selected Minerals for Various Age Groups (continued) Life Stage

Iron (mg/day)

Magnesium (mg/day)

Phosphorus (mg/day)

Selenium (μg/day)

0 – 6 mo

0.27

30

100

15

7–12 mo

11

75

275

20

1–3 yrs

7

80

460

20

4 – 8 yrs

10

130

500

30

9–13 yrs

8

240

1,250

40

14 –18 yrs

11

410

1,250

55

19–30 yrs

8

400

700

55

Infants

Children

Males

31–50 yrs

8

420

700

55

51–70 yrs

8

420

700

55

>70 yrs

8

420

700

55

8

240

1,250

40

14 –18 yrs

15

360

1,250

55

19–30 yrs

18

310

700

55

31–50 yrs

18

320

700

55

51–70 yrs

8

320

700

55

>70 yrs

8

320

700

55

≤18 yrs

27

400

1,250

60

19–30 yrs

27

350

700

60

31–50 yrs

27

360

700

60

10

360

1,250

70

19–30 yrs

9

310

700

70

31–50 yrs

9

320

700

70

Females 9–13 yrs

Pregnancy

Lactation ≤18 yrs

HE Eating Disorders.indd 1 0

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Appendix A

161

Recommended Intakes of Selected Minerals for Various Age Group Life Stage

Zinc (mg/day)

Sodium (g/day)

Chloride (g/day)

Potassium (g/day)

Infants 0–6 mo

2

0.12

0.18

0.4

7–12 mo

3

0.37

0.57

0.7

Children 1–3 yrs

3

1.0

1.5

3.0

4–8 yrs

5

1.2

1.9

3.8

9–13 yrs

8

1.5

2.3

4.5

14–18 yrs

11

1.5

2.3

4.7

19–30 yrs

11

1.5

2.3

4.7

31–50 yrs

11

1.5

2.3

4.7

51–70 yrs

11

1.3

2.0

4.7

>70 yrs

11

1.2

1.8

4.7

9–13 yrs

8

1.5

2.3

4.5

14–18 yrs

9

1.5

2.3

4.7

19–30 yrs

8

1.5

2.3

4.7

31–50 yrs

8

1.5

2.3

4.7

51–70 yrs

8

1.3

2.0

4.7

>70 yrs

8

1.2

1.8

4.7

≤18 yrs

13

1.5

2.3

4.7

19–30 yrs

11

1.5

2.3

4.7

31–50 yrs

11

1.5

2.3

4.7

≤18 yrs

14

1.5

2.3

5.1

19–30 yrs

12

1.5

2.3

5.1

31–50 yrs

12

1.5

2.3

5.1

Males

Females

Pregnancy

Lactation

Note: This table presents Recommended Dietary Allowances (RDAs) in bold type and Adequate Intakes (AIs) in ordinary type. Source: Adapted from Dietary Reference Intake Tables: The Complete Set. Institute of Medicine, National Academy of Sciences. Available online at www.nap.edu.


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appendix B a heaLthY BodY Weights Body Mass index (BMi) Body mass index, or BMI, is the measurement of choice for determining health risks associated with body weight. BMI uses a mathematical formula that takes into account both a person’s height and weight. BMI equals a person’s weight in kilograms divided by height in meters squared (BMI=kg/m2).

risK of assoCiated disease aCCording to BMi and Waist siZe for aduLt L s Lt BMi

Waist less than or equal to 40 in. (men) or 35 in. (women)

Waist greater than 40 in. (men) or 35 in. (women)

18.5 or less ess

Underweight

N/A

N/A

18.5 –24.9

Normal

N/A

N/A

25.0 –29.9

Overweight

Increased

High

30.0 –34.9

Obese

High

Very High

35.0 –39.9

Obese

Very High

Very High

40 or greater

Extremely Obese

Extremely High

Extremely High

determining Your Body Mass index (BMi) To use the table on the following page, find the appropriate height in the left-hand column. Move across the row to the given weight. The number at the top of the column is the BMI for that height and weight. Then use the table above to determine how at risk you are for developing a weight-related disease.

162


94 97 100 104 107 110 114 118 121 125 128 132 136 140 144 148 152 156

59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76

99 102 106 109 113 116 120 124 127 131 135 139 143 147 151 155 160 164

96

20

104 107 111 115 118 122 126 130 134 138 142 146 150 154 159 163 168 172

100

21

109 112 116 120 124 128 132 136 140 144 149 153 157 162 166 171 176 180

105

22

114 118 122 126 130 134 138 142 146 151 155 160 165 169 174 179 184 189

110

23

119 123 127 131 135 140 144 148 153 158 162 167 172 177 182 186 192 197

115

24

26

124 128 132 136 141 145 150 155 159 164 169 174 179 184 189 194 200 205

119

128 133 137 142 146 151 156 161 166 171 176 181 186 191 197 202 208 213

124

Weight (lb)

25

133 138 143 147 152 157 162 167 172 177 182 188 193 199 204 210 216 221

129

27

138 143 148 153 158 163 168 173 178 184 189 195 200 206 212 218 224 230

134

28

Source: Adapted from Partnership for Healthy Weight Management, http://www.consumer.gov/weightloss/bmi.htm.

91

19

58

Height (in.)

BMI (kg/m2 )

143 148 153 158 163 169 174 179 185 190 196 202 208 213 219 225 232 238

138

29

148 153 158 164 169 174 180 186 191 197 203 207 215 221 227 233 240 246

143

30

167 173 179 185 191 197 204 210 216 223 230 236 243 250 258 265 272 279 287

35

191 198 204 211 218 225 232 240 247 255 262 270 278 286 294 302 311 319 328

40

Appendix B

163

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164

BMI-for-Age Growth Charts

2

2

4


9/16/10 12:22 PM

Appendix B

165

24

20

2


2

9/16/10 12:22 PM

appendix C a BLood vaLues of nutritionaL reLevanCe Red blood cells Men

4.6–6.2 million/mm3

Women

4.2–5.2 million/mm3

White blood cells ells

5,000–10,000/mm3

Calcium

9–11 mg/100 mL

Iron Men

75–175 μg/100 mL

Women

65–165 μg/100 mL

Zinc

0.75–1.4 μg/mL

Potassium

3.5–5.0 mEq/L

Sodium

136–145 mEq/L

Vitamin A

20–80 μg/100 mL

Vitamin B12

200–800 pg/100 mL

Vitamin C

0.6–2.0 mg/100 mL

Folate

2–20 ng/mL

pH

7.35–7.45

Total protein

6.6–8.0 g/100 mL

Albumin

3.0–4.0 g/100 mL

Cholesterol

less than 200 mg/100 mL

Glucose

60–100 mg/100 mL blood, 70–120 mg/100 mL serum

Source: Handbook of Clinical Dietetics, American Dietetic Association (New Haven, Conn.: Yale University Press, 1981); and Committee on Dietetics of the Mayo Clinic, Mayo Clinic Diet Manual (Philadelphia: W. B. Saunders Company, 1981), pp. 275–277.

166

Source: http://www.mypyramid.gov/downloads/MyPyramid_Anatomy.pdf.

appendix d a

usda’s MYpYraMid

167

g gLossarY absorption The process of taking substances from the digestive tract into body cells adenosine triphosphate (ATP) The high-energy molecule used by the body to perform energy-requiring activities adequate intakes (AIs) Intakes recommended by the Dietary Reference Intakes that should be used as a goal when no Recommended Dietary Allowance exists; these values are an approximation of the average nutrient intake that appears to sustain a desired indicator of health. aerobic exercise Exercise that uses aerobic metabolism, which uses oxygen and improves cardiovascular fitness amenorrhea Delayed onset or the absence of three or more consecutive menstrual cycles amino acids The building blocks of proteins; each contains a carbon atom bound to a hydrogen atom, an amino group, an acid group, and a side chain. anorexia athletica An eating disorder in which compulsive exercise is used to control weight anorexia nervosa An eating disorder characterized by a distorted body image, self-starvation, and loss of 15% or more of normal weight for age and height antioxidant A substance that is able to neutralize reactive molecules and hence reduce the amount of oxidative damage that occurs appetite A drive to eat specific foods that is not necessarily related to hunger atp See Adenosine triphosphate. Bigorexia See Muscle dysmorphia. Binge Consumption of an abnormally large amount of food in a relatively short period of time

168

Glossary

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Binge-eating disorderâ•… An eating disorder characterized by binge eating that is not followed by purging or other compensatory behavior Bioelectric impedance analysisâ•… A technique for estimating body composition that measures body fat by directing electric current through the body and calculating resistance to flow BMIâ•… See Body Mass Index Body compositionâ•… The relative proportions of fat and lean tissue (bone, muscle, fluids, and internal organs) that make up the body Body imageâ•… The way a person perceives or imagines his or her body Body mass index (BMI)â•… The currently accepted measure for evaluating desirable body weight; it is calculated by dividing weight in kilogram by height in meters squared. Bulimia nervosaâ•… An eating disorder characterized by repeated cycles of binging and purging Calorieâ•… The amount of heat needed to raise one gram of water 1°C (34°F). It is commonly used to refer to a kilocalorie, which is 1,000 calories. Cholesterolâ•… A lipid made only by animal cells that consists of multiple chemical rings Cortisolâ•… A hormone secreted by the adrenal gland in response to stress; it affects blood sugar regulation. Daily Valueâ•… A nutrient reference value used on food labels to help consumers see how foods fit into their overall diets Diabetesâ•… A disease caused by either insufficient insulin production or decreased sensitivity of cells to insulin. It results in elevated blood glucose levels. Dietary References Intakes (DRIs)â•… A set of reference values for the intake of energy, nutrients, and food components that can be used for planning and assessing the diets of healthy people in the United States and Canada Digestionâ•… The process of breaking food into components small enough to be absorbed into the body


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Nutrition and eating disorders Eating disorderâ•… A group of conditions characterized by a pathological concern with body weight and shape Eating disorders not otherwise specified (EDNOS)â•… Eating disorders that do not meet the defining criteria of anorexia or bulimia Endorphinsâ•… Compounds that cause a natural euphoria and reduce the perception of pain under certain stressful conditions. Endorphins may be the cause of the feeling known as “runner’s high.” Elementâ•… A substance made of only one type of atom Energy balanceâ•… The amount of energy consumed in the diet compared with the amount expended by the body over a given period Energy-yielding nutrientsâ•… Nutrients that provide calories Enzymesâ•… Protein molecules that accelerate the rate of specific chemical reactions without being changed themselves Essential nutrientsâ•… Nutrients that must be supplied in the diet because the body cannot make them or cannot make enough of them to meet needs Estimated Average Requirements (EARs)â•… Intakes recommended by the DRIs that meet the estimated nutrient needs (as defined by a specific indicator of adequacy) of 50% of individuals in a particular gender and life-stage group Estimated Energy Requirements (EERs)â•… The amount of energy calculated to maintain body weight in a healthy person based on age, gender, size, and activity level. Extreme obesityâ•… A condition in which body weight is 100 pounds (45 kg) above healthy body weight or body mass index is greater than 40 kg/m2; also called morbid obesity Fatty acidâ•… An organic molecule made up of a chain of carbons linked to hydrogens with an acid group at one end Female athlete triadâ•… A syndrome in young female athletes that involves disordered eating, amenorrhea, and low bone density Fiberâ•… A mixture of substances, most of which are carbohydrate, in plant foods that are not broken down by human digestive enzymes


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Glossary

171

Fortificationâ•… The addition of nutrients to foods, such as the addition of vitamin D to milk Free radicalâ•… One type of highly reactive molecule that causes oxidative damage Gastrointestinal tractâ•… The long, narrow tube that extends from the mouth to the anus in which digestion and absorption of nutrients occurs Geneâ•… A section of DNA that codes for a protein Ghrelinâ•… A hormone produced by the stomach that helps regulate food intake Homeostasisâ•… A physiological state in which a stable internal body environment is maintained Hormonesâ•… Chemical messengers that are produced in one location, released into the blood, and elicit responses at other locations in the body Hungerâ•… The physiological drive to consume food Inappropriate compensatory behaviorsâ•… A term used to describe the behaviors that people with bulimia nervosa use to rid the body of excess calories; they include self-induced vomiting, the misuse of laxatives, diuretics or enemas, fasting, and excessive exercise. Insulinâ•… A hormone made in the pancreas that allows the uptake of glucose by body cells and has other metabolic effects, such as stimulating protein and fat synthesis and the synthesis of glycogen in liver and muscle Kilocalorieâ•… A unit of heat that is used to express the amount of energy provided by foods; it is commonly called a calorie. Kilojouleâ•… A measure of work that can be used to express energy intake and energy output; 4.18 kjoules = 1 kilocalorie Lanugo hairâ•… Abnormal fine hair that grows all over the body. It is a symptom of anorexia nervosa. Lean body massâ•… The proportion of body mass that is not fat Leptinâ•… A protein hormone produced by fat cells that signals information about the amount of body fat


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172

Nutrition and eating disorders Macronutrientsâ•… Nutrients needed by the body in relatively large amounts. These include water, carbohydrates, fats, and protein. Malnutritionâ•… Any condition resulting from an energy or nutrient intake that is either above or below optimal intake Melatoninâ•… A hormone involved in maintaining sleep cycles Metabolismâ•… The sum of all the chemical reactions that take place in a living organism Micronutrientsâ•… Nutrients needed by the body in small amounts. These include vitamins and minerals. Morbid obesityâ•… See Extreme obesity. Mucusâ•… A viscous fluid secreted by glands in the gastrointestinal tract and other parts of the body. It acts to lubricate, moisten, and protect cells from harsh environments. Muscle dysmorphiaâ•… An eating disorder that is more common in men, also called bigorexia, reverse anorexia, or Adonis Complex; it involves an obsession with not being muscular enough. Neurotransmitterâ•… A chemical substance produced by a nerve cell that can stimulate or inhibit another cell Night-eating syndromeâ•… An eating disorder that involves lack of hunger in the morning, followed by insomnia and excessive eating at night Nutrient densityâ•… A measure of the nutrients provided by a food relative to the energy it contains Nutrientsâ•… Chemical substances in foods that provide energy, structure, and regulation for body processes Nutritionâ•… The science that studies the interactions that occur between living organisms and food Obeseâ•… Having a body mass index of greater than or equal to 30 kg/ m2 in adults or greater than or equal to the 95th percentile for age and gender in those under 20 years of age Obesityâ•… The condition that results when there is excess body fat; it is defined as a body mass index (BMI) greater than or equal to 30 kg/m2 in adults or greater than or equal to the 95th percentile for age and gender in those under 20 years of age.


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Glossary

173

Osteopeniaâ•… Reduced bone density Osteoporosisâ•… A bone disorder characterized by a reduction in bone mass, increased bone fragility, and an increased risk of fractures Overnutritionâ•… A type of poor nutritional status that results from consuming an excess of calories or specific nutrients Overweightâ•… Having a body mass index greater than or equal to 25 kg/m2 in adults or greater than or equal to the 85th percentile and less than the 95th percentile in children. Phytochemicalâ•… A substance found in plant foods that is not an essential nutrient but may have health-promoting properties Picaâ•… An eating disorder that involves eating nonfood substances Prebioticsâ•… Substances that pass undigested into the colon and stimulate the growth and/or activity of certain types of bacteria Probioticsâ•… Products that contain live bacteria, which when consumed live temporarily in the colon and confer health benefits on the host Purgingâ•… Ridding the body of calories with abnormal compensatory behaviors such as self-induced vomiting or the misuse of laxatives Recommended Dietary Allowances (RDAs)â•… Intakes recommended by the Dietary Reference Intakes that are sufficient to meet the nutrient needs of almost all healthy people in a specific life-stage and gender group Satietyâ•… The feeling of fullness after eating Saturated fat or saturated fatty acidâ•… A fatty acid that contains no carbon-carbon double bonds Self-esteemâ•… The sum of how a person feels about himself or herself Serotoninâ•… A neurotransmitter that is involved in sleep, depression, memory, and other neurological processes Skinfold thicknessâ•… A measure of the amount of fat under the skin used to estimate total body fat


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174

Nutrition and eating disorders Starchâ•… A carbohydrate made of many glucose molecules linked in straight or branching chains; the bonds that hold the glucose molecules together can be broken by the human digestive enzymes. Starvationâ•… The form of malnutrition resulting from lack of food Subcutaneous fatâ•… Body fat located just under the skin Sugarâ•… A simple carbohydrate molecule made of one or two sugar units Tolerable Upper Intake Level (UL)â•… The maximum daily intake of a nutrient that is unlikely to be dangerous to most people in a specified life-stage and gender group Trans fatâ•… A type of unsaturated fat that increases the risk of heart disease; the word trans is typically set in italics when chemical properties are being discussed. Triglycerideâ•… The major form of lipid in food and in the body. It consists of three fatty acids attached to a glycerol molecule. Undernutritionâ•… A type of malnutrition that occurs when the amount of energy or nutrients is insufficient to meet needs. Underwater weighingâ•… A method of assessing body composition that uses weight on land compared with weight under water Underweightâ•… Having a body mass index of less than 18.5 kg/m2 in adults and less than the 5th percentile in children Unsaturated fat or unsaturated fatty acidâ•… A fatty acid that contains one or more carbon-carbon double bonds Visceral fatâ•… Body fat that is located around internal organs


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BiBLiographY American Anorexia Bulimia Association, Inc. Available online at http:// www.aabainc.org/general/index.html American Psychiatric Association, Practice Guidelines. Treatment of Patients With Eating Disorders, Third Edition, July 2006. Available online at http://www.psychiatryonline.com/pracGuide/pracGuide Topic_12.aspx American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 4th ed. Washington, D.C.: American Psychiatric Association, 1994. Adams, Cecil. “Were There Really Vomitoriums in Ancient Rome?” The Straight Dope. November 2002. Available online at http://www. straightdope.com/columns/021101.html Attia, E. “Anorexia Nervosa: Current Status and Future Directions.” Annual Review of Medicine. Aug 31, 2009. (Epub ahead of print.) Ayala, G.X., M. Rogers, E.M. Arredondo, et al. “Away-from-home Food Intake and Risk for Obesity: Examining the Influence of Context.” Obesity. 16:1002–1008, 2008. Batterham, R.L., M.A. Cowley, C.J. Small, et al. “Gut Hormone PYY Physiologically Inhibits Food Intake.” Nature. 418:650–654, 2004. Branson, R., N. Potoczna, J.G. Kral, et al. “Binge Eating as a Major Phenotype of Melanocortin 4 Receptor Gene Mutations.” New England Journal of Medicine. 348:1096–1103, 2003. Brownell, K.D. and M.A. Napolitano. “Distorting Reality for Children: Body Size Proportions of Barbie and Ken Dolls.” International Journal of Eating Disorders. 3: 295–298, 1995. Castro, J., L. Lázaro, F. Pons, et al. “Predictors of Bone Mineral Density Reduction in Adolescents with Anorexia Nervosa.” Journal of the American Academy of Child and Adolescent Psychiatry. 39:13651370, 2000.

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Nutrition and eating disorders CBS. “Diet Industry Is Big Business: Americans Spend Billions on Weight-Loss Products Not Regulated By the Government.” CBS Evening News, Dec 1, 2006. Available online at http://www.cbsnews. com/stories/2006/12/01/eveningnews/main2222867.shtml. Centers for Disease Control and Prevention. “About BMI for Children and Teens.” 2009. Available online at http://www.cdc.gov/healthy weight/assessing/bmi/childrens_BMI/about_childrens_BMI.html. Centers for Disease Control and Prevention, National Center for Health Statistics. “Mean Body Weight, Height, and Body Mass Index, United States 1960-2002.” Available online at http://www.cdc.gov/ nchs/pressroom/04news/americans.htm. Accessed March 20, 2010. Centers for Disease Control and Prevention. “Obesity and Overweight, Health Consequences.” Available online at http://www.cdc.gov/ obesity/causes/health.html. Accessed September, 2009. Consumer Reports. “Dieters Are Sure They’ll Win at Losing.” May 2007. Available online at http://www.consumerreports.org/health/ healthy-living/diet-nutrition/diets-dieting/dieters-are-optimisticabout-weight-loss-survey-shows/overview/dietpoll.htm. Conway, J.M. “Ethnicity and Energy Stores.” American Journal of Clinical Nutrition. 62: 1067S–1071S, 1995. Corson, P.W. and Andersen, A.E. “Body Image Issues Among Boys and Men.” Body Image: A Handbook of Theory, Research, and Clinical Practice. Edited by Thomas F. Cash and Thomas Pruzinsky. 192-198, 2004. Cummings, D.E., D.S. Weigle, R.S. Frayo, et al. “Plasma Ghrelin Levels After Diet-induced Weight Loss or Gastric Bypass Surgery.” New England Journal of Medicine. 346: 1623–1630, 2002. de Krom, M., F. Bauer, D. Collier, et al. “Genetic Variation and Effects on Human Eating Behavior.” Annual Review of Nutrition. 29:283304, 2009. Healthy Place. “Eating Disorders: Pica.” Available online at http://www. healthyplace.com/eating-disorders/main/eating-disorders-pica/ menu-id-58/.


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Fields, D. A., G.R. Hunter, and M.I. Goran. “Validation of the BOD POD with Hydrostatic Weighing: Influence of Body Clothing.” International Journal of Obesity and Related Metabolic Disorders. 24: 200–205, 2000. Food and Drug Administration, Center for Food Safety and Applied Nutrition. “A Food Labeling Guide.” Available online at http:// www.fda.gov/Food/GuidanceComplianceRegulatoryInformation/ GuidanceDocuments/FoodLabelingNutrition/FoodLabelingGuide/ default.htm. Accessed March 20, 2010. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrates, Fiber, Fat, Protein, and Amino Acids. Washington, D.C.: National Academies Press, 2002. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington, D.C.: National Academies Press, 1997. Forrest, K.Y.Z. and W. L. Stuhldreher. “Patterns and Correlates of Body Image Dissatisfaction and Distortion Among College Students.” American Journal of Health Studies. 22:18-25, 2007. Gallagher, D., S. Heymsfield, M. Heo, et al. “Healthy Percentage Body Fat Ranges: An Approach for Developing Guidelines Based on Body Mass Index.” American Journal of Clinical Nutrition. 72:694–701, 2000. Halmi, K.A. “Anorexia Nervosa: An increasing problem in children and adolescents.” Dialogues in Clinical Neuroscience. 11:100-103, 2009. Herzog, D.B., D.N. Greenwood, D.J. Dorer, et al. “Mortality in Eating Disorders: A Descriptive Study.” International Journal of Eating Disorders. 28: 20-26, 2000. Hoek H.W., and D. van Hoeken. “Review of the prevalence and incidence of eating disorders.” International Journal of Eating Disorders. 34:383–96, 2003. Kaye, W.H., T.E. Weltzin, L.K. Hsu, et al. “Amount of Calories Retained After Binge Eating and Vomiting.” American Journal of Psychiatry. 150: 969–971, 1993.


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178

Nutrition and eating disorders Keys, A., J. Brozek, A. Henschel, et al. The Biology of Human Starvation, vols. 1 and 2. Minneapolis: University of Minnesota Press, 1950. Kuwana, E. “Discovering the Sweet Mysteries of Chocolate.” Available online at http://faculty.washington.edu/chudler/choco.html. Accessed March 20, 2010. Mammal Society. “Mammal Record Breakers.” Available online at http://abdn.ac.uk/mammal/fattest.shtml. Accessed September 2009. Mills, M.E. “Craving More Than Food: The Implications of Pica During Pregnancy.” Nursing for Women’s Health. 11:266-273, 2007. National Institutes of Health, NHLBI. “Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults.” Available online at: http://www.nhlbi.nih.gov/guidelines/ obesity/ob_home.htm. Accessed March 20, 2010. National Public Radio. “Marketplace: Our Loss, Diet Industry’s Gain.” May 30, 2007. Available online at http://marketplace.public radio.org/display/web/2007/05/30/our_loss_diet_industrys_gain/. Accessed March 20, 2010. Redinger, R.N. “The Physiology of Adiposity.” Journal of the Kentucky Medical Association. 106: 53–62, 2008. Slof-Op ‘t Landt, M.C., E.F. van Furth, I. Meulenbelt, et al. “Eating Disorders: From twin studies to candidate genes and beyond.” Twin Research and Human Genetics. 8: 467-82, 2005. Stice, E. “Sociocultural Influences on Body Weight and Eating Disturbance.” Eating Disorders and Obesity: A Comprehensive Handbook, 2nd ed., eds. C.G. Fairburn and K.D. Brownell. New York: The Guilford Press, 2002, pp. 103–107. Strober, M. and C.M. Bulik. “Genetic Epidemiology of Eating Disorders.” Eating Disorders and Obesity: A Comprehensive Handbook, 2nd ed., eds. C.G. Fairburn and K.D. Brownell. New York: The Guilford Press, 2002, pp. 238–242. Townsend, A.B. “Night Eating Syndrome.” Holistic Nursing Practice. 21: 217-221, 2007.


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U.S. Department of Health and Human Services. “2008 Physical Activity Guidelines for Americans.” Washington, D.C.: Department of Health and Human Services, 2008. Vandereycken, W. “History of Anorexia Nervosa and Bulimia Nervosa.” Eating Disorders and Obesity: A Comprehensive Handbook, 2nd ed., eds. C.G. Fairburn and K.D. Brownell. New York: The Guilford Press, 2002, pp. 151–154. Willcox, B.J., D.C. Willcox, H. Todoriki, et al. “Caloric Restriction, the Traditional Okinawan Diet, and Healthy Aging: The diet of the world’s longest-lived people and its potential impact on morbidity and life span.” Annals of the New York Academy of Sciences. 1114:434–455, 2007.


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further resourCes American Dietetic Association. “Position of the American Dietetic Association: Nutrition intervention in the treatment of anorexia nervosa, bulimia nervosa and eating disorders not otherwise specified (EDNOS).” Journal of the American Dietetic Association. 101: 810–818, 2008. American Psychiatric Association. Diagnostic and Statistical Manual for Mental Disorders, 4th ed. (DSM-IV). Washington, D.C.: American Psychiatric Press, 1994. Brownell, K.D., and C.G. Fairburn, eds. Eating Disorders and Obesity: A Comprehensive Handbook, 2nd ed. New York: The Guilford Press, 2002. Duyff, Roberta. American Dietetic Association Complete Food and Nutrition Guide, 3rd ed. New Jersey: John Wiley & Sons, 2008. U.S. Department of Health and Human Services. A Healthier You: Based on the Dietary Guidelines for Americans. Office of Disease Prevention and Health Promotion U.S., 2005.

Web sites Weight-control Information Network http://win.niddk.nih.gov/index.htm The Weight-control Information Network provides the general public, health professionals, the media, and Congress with upto-date, science-based information on weight control, obesity, physical activity, and related nutritional issues. National Eating Disorders Screening Program http://www.mentalhealthscreening.org/events/nedsp/index.aspx The National Eating Disorders Screening Program’s site focuses on the three main types of eating disorders - anorexia nervosa, bulimia nervosa, and binge eating disorder. The goal is to raise

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Further Resources

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the level of awareness about eating disorders and to encourage people who may be suffering from eating disorders to seek further help and treatment. Participating colleges and universities are encouraged to network with community groups and other internal departments, thereby creating liaisons that can continue to be utilized throughout the year. American Anorexia/Bulimia Association www.aabaphila.org The American Anorexia/Bulimia Association of Philadelphia is a nonprofit organization that provides services and programs for anyone interested in or affected by anorexia, bulimia, or related disorders. It aims to educate people about these disorders and help to prevent them. Its referral programs and support groups assist in the treatment and recovery process. Overeaters Anonymous www.oa.org Overeaters Anonymous (OA) offers a program of recovery from compulsive eating using the Twelve Steps and Twelve Traditions of OA. Worldwide meetings and other tools provide a fellowship of experience, strength, and hope in which members respect one another’s anonymity. OA charges no dues or fees; it is self-supporting through member contributions. The Web site provides access to information and locations for group meetings. National Eating Disorder Association Information and Referral Program www.nationaleatingdisorders.org This organization is dedicated to providing education, resources, and support to those affected by eating disorders. The site benefits people living with an eating disorder, family members or friends looking to offer support to a loved one, and treatment professionals looking to help others.


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piCture Credits Page 11: Arieliona /Shutterstock

69: Newscom

16: AFP Photo/Paul J. Richards/Newscom

72: Bettmann/Corbis

25: © Infobase Publishing

7 74: Newscom

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89: iofoto/Shutterstock (left); © Infobase Publishing (right)

38: Courtesy USDA 44: © Infobase Publishing


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59: HBO/AP Images 62: Paul Drinkwater/NBCU Photo Bank via AP Images 68: Naturhistorisches Museum, Vienna, Austria/ Ali Meyer/The Bridgeman Art Library

117: © Infobase Publishing 129: © Infobase Publishing 132: © Infobase Publishing 140: © Infobase Publishing 148: Courtesy Men’s Fitness 151: © Infobase Publishing

182

indeX

indeX

Page numbers in italics indicate photos or illustrations; page numbers followed by t indicate tables.

a

abnormal eating 47–51. See also eating disorders absorption 24, 25 actresses 73, 74, 75, 77 adenosine triphosphate (ATP) 24 Adequate Intakes (AIs) 30 adolescence body image and 77, 79 eating disorders and 54 adolescent girls, low body weight in 95 Adonis complex 149 advertising, food choice and 17 affection, food and 10 age eating disorders and 55–56 percentage body fat and 85 AIs (Adequate Intakes) 30 amenorrhea 113–114, 152 American ideal of body image 70–75, 72, 73, 74, 76, 78 American Psychiatric Association 116 amino acids 28–29 anorexia athletica 150 anorexia nervosa 103–122 in athletes 149 behavioral component 108–112 body image distortion and 79–80 characteristics of 49, 49–51, 50–51t, 105, 106t in children 143–144 historical overview 104–105 in men 146 overview 122 physical effects of 112–116, 113, 115

psychological component 106–108 treatment of 116–121, 117 types of 105, 106t, 107–108 antidepressant drugs 120–121, 135, 141 antioxidants 29 appetite 42 athletes body fat and 87 eating disorders in 55, 56, 149–152, 151 female, low body weight in 95, 151, 151–152 ATP (adenosine triphosphate) 24 availability, food choice and 15, 16

B

bacteria, intestinal 26 balance, in diet 46 Barbie dolls 75 Basic Four 40 Basic Seven 40 BED. See binge-eating disorder behavioral component of anorexia nervosa 108–112 bulimia nervosa 128–131, 129 beliefs, food choice and 17 bigorexia 149 binge-eating disorder (BED) 49, 50–51t, 51, 138–141, 140, 141t binge-eating/purging type anorexia nervosa 105, 106t, 107–108 binges 51, 128–130 bioelectric impedance analysis 87–88 blood sugar control 152–153

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Nutrition and eating disorders BMI. See body mass index BMI-for-age growth charts 84, 86 body composition 85–92, 89, 91 body fat measurement of 87–88, 89 percentage of, and age 85 subcutaneous fat 88 visceral fat 89, 90–91 body image 67–81 in anorexia nervosa 49, 51, 106 in bulimia nervosa 127 changing American ideal of 70–75, 72, 73, 74, 76, 78 development of 77–79 historical and cultural ideals of 67–70, 68, 69 media message on 75–77 of men 147 overview 81 problems with 79–80 self-esteem and 63, 77, 127 sociocultural factors and 61 toys and 147 body mass index (BMI) 82–85, 83 body shape 89–92, 91, 92t body weight. See also overweight; underweight determinants of 96–102, 97t, 98t healthy 82–85, 83 obsession with 60 overview 102 regulation of 99–101 Bruch, Hilde 105, 108 bulimia nervosa 123–136 in athletes 149–150 behavioral component 128–131, 129 characteristics of 49, 50–51t, 51, 125–126, 126t historical overview 124 in men 146 overview 135–136 physical effects of 131–133, 132 psychological disturbances 127–128


treatment of 133–135 types of 126, 126t, 127

C

calorie, defined 22 calorie content of various nutrients 22 calorie requirements 31, 96–97, 98t Campbell, Naomi 74 carbohydrates 27–28, 27t Cheeseburger Bill 94 childhood, eating disorders in 55–56, 143–145 chocolate 12 cholesterol 28 comfort foods 10–11, 11 compensatory behaviors, inappropriate 125, 126 compulsive exercise 111, 150 confrontation 63–65 control, need for 60–61 cortisol 142 cultural food rituals 13 cultural ideal of body image 61, 69, 69–70. See also American ideal of body image

D

Daily Values 35 depression eating disorders and 58, 107, 127, 139 medications for 120–121, 135, 141 overweight and 93 diabetes eating disorders and 152–153 obesity and 33 diet, healthy. See healthy diet Dietary Guidelines for Americans 35–37, 37t Dietary References Intakes (DRIs) 30–31 dietary supplements 21, 31

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Index dieting 60, 65 diet programs and products 34, 60 digestion 24, 25 digestive system 24, 25 dirt eating 64 discrimination against overweight people 93–94 dissatisfaction, with body image 79 distortion, of body image 79 diuretics 131, 132–133 dopamine 58 DRIs (Dietary References Intakes) 30–31

E

EARs (Estimated Average Requirements) 30 eating, frequency of 46–47 eating behavior abnormal 47–51. See also eating disorders external factors affecting 42–43 internal factors affecting 43–45, 44 normal 41–42 overview 53 eating disorders. See also anorexia nervosa; bulimia nervosa; eating disorders not otherwise specified binge-eating disorder 49, 50–51t, 51, 138–141, 140, 141t categories of 49, 50–51t causes of 56–63, 57 described 9–10, 47 helping someone with 63–65 myths and realities of 52 overview 66 pica 64 prevention of 65–66 eating disorders not otherwise specified (EDNOS) 137–154 in athletes 149–152, 151 binge-eating disorder 138–141, 140, 141t


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childhood and 143–145 described 49, 137–138, 138t diabetes and 152–153 in men 146–149, 148 night-eating syndrome 142 overview 154 pregnancy and 145–146 EDNOS. See eating disorders not otherwise specified EERs. See Estimated Energy Requirements emotions, food and 10–11, 11, 43 endorphins 99 energy body fat stores and 88 sources of 22–23 energy balance 23, 96 energy balance regulation 99–101 energy-yielding nutrients 22 enzymes, digestive 24 essential nutrients 21 Estimated Average Requirements (EARs) 30 Estimated Energy Requirements (EERs) 31, 96–97, 98t estrogen 96, 113, 152 exercise compulsive 111, 150 energy needs and 100 recommendations for 99 extreme obesity 84

F

family pressure 61 family problems, anorexia nervosa and 108 fashion models 70, 75, 76, 77 fast food culture 17 fast food restaurants, lawsuits against 94 fat, body. See body fat fats, saturated vs. unsaturated 28. See also lipids fatty acids 28 female athlete triad 95, 151, 151–152

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Nutrition and eating disorders females, eating disorders in 55 fiber, dietary 27, 28 flapper look 71, 72 food abundance, eating disorders and 69–70 food-avoidance emotional disorder 144 food choices, reasons for 14–18, 42–43 Food for Young Children 40 food group systems 40 Food Guide Pyramid 40 food intake regulation 43–45, 44 food intake restriction, health risks of 95–96 food labels 33–35, 36 food preferences 16 food preoccupation, in anorexia nervosa 110–111 food shortages, historical impact of 114 fortification 21 free radicals 29

G

Gandhi, Mohandas “Mahatma” 114 gastrointestinal (GI) tract 24, 25 gender difference, eating disorders and 55 genetics 48, 56–58, 57, 100–101 ghrelin 45 GI (gastrointestinal) tract 24, 25 Great Depression era 72 growth charts, BMI-for-age 84, 86 Guantanamo Bay, Cuba 114

H

habit, food choice and 16–17 health risks overweight and 33, 93 underweight and 94–96 health status, food choice and 15 healthy body weight. See body weight


healthy diet characteristics of 45–47 tools for. See nutrition tools heart disease, risk factors for 33 historical ideal of body image 67–69, 68 holidays, food and 13–14 homeostasis 23 hormonal changes in anorexia nervosa 113–114 in female athlete triad 152 in starvation 96 hormones 23, 45 hunger 42, 43–45, 44 hunger strikes 114 hyperactivity, in anorexia nervosa 111

I

identity, food and 11–13 immigrant culture 72 inappropriate compensatory behaviors 125, 126 inheritance. See genetics insects as food 14 insulin 45, 152, 153 intestinal bacteria 26 iron overdose 31

J

Johns, Daniel 62

K

ketones 112 kilocalorie 22 kilojoule 22

L

lanugo 116 lawsuits against fast food restaurants 94 laxatives 131, 132–133

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Index lean body mass 85 leanness, natural 95 leptin 45, 48, 142 lifestyle body weight and 101 food choice and 15 lipids 27t, 28

M

macronutrients 27, 27t males. See men malnutrition 31–33, 32 meal frequency 46–47 media, ideal body image and 75–77 medications for anorexia nervosa 120–121 for binge-eating disorder 141 for bulimia nervosa 134–135 melatonin 142 memories, food and 10–11 men, eating disorders in 55, 146– 149, 148 menstrual periods, absence of 113–114, 152 metabolism 24 micronutrients 27, 27t minerals 27t, 29–30 mineral supplements, dangers of 31 misinformation about eating disorders 52 Miss America Pageant 71, 73 moderation, in diet 46 Monroe, Marilyn 73, 74 morbid obesity 84 Moss, Kate 75, 76 mucus 24 muscle dysmorphia 149 MyPyramid 37–39, 38 myths of eating disorders 52

N

neurotransmitters 45, 58 night-eating syndrome 142


187

nonpurging type bulimia 126, 127, 131 normal eating 41–42. See also eating behavior nutrient density 37 nutrients 20–33 classes of 26–30, 27t digestion and absorption of 24, 25 excess or deficiency of 31–33, 32 functions of 21–23 overview 39–40 requirements for 30–31 sources of 20–21 utilization of 24 nutritional rehabilitation for anorexia nervosa 118–119 for bulimia nervosa 133 “Nutrition Facts” label 35, 36 nutrition tools 33–39 Dietary Guidelines 35–37, 37t food labels 33–35, 36 MyPyramid 37–39, 38

O

obesity 33, 84, 92–94 obesity genes 101. See also genetics obsession with weight and dieting 60 osteopenia 114 osteoporosis 95, 114, 152 overactivity, in anorexia nervosa 111 overnutrition 33 overweight 33, 84, 92–94

P

PA level. See physical activity (PA) level parental pressure 61, 65 Pavlov, Ivan 43 peer pressure 61 peptide YY 45 perfectionism 60, 63, 107

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188

Nutrition and eating disorders Personal Responsibility in Food Consumption Act 94 pervasive refusal syndrome 145 physical activity compulsive 111, 150 energy needs and 100 recommendations for 99 physical activity (PA) level 97, 97t physical effects of anorexia nervosa 112–116, 113, 115 of bulimia nervosa 131–133, 132 physiological factors in eating behavior 43–45, 44 phytochemicals 21 pica 64 placebo 141 plump physique, cultural desirability of 69, 69 prebiotics 26 preferences for foods 16 pregnancy 95, 145–146 prejudice against overweight people 93–94 probiotic therapy 26 protein, dietary 27t, 28–29 psychological aspects of food 9–19 emotions and 10–11, 11, 43 in food choice decisions 14–18 identity and 11–13 overview 9–10, 18–19 social interactions and 13–14 psychological factors in anorexia nervosa 106–108 in bulimia nervosa 127–128 eating disorders and 57, 58–61, 59 psychological impacts, of being overweight 93–94 psychosocial therapy 119–120, 134 punishment, food as 12 purging 51, 111–112, 130–131 purging type bulimia 126, 127

R

RDAs (Recommended Dietary Allowances) 30


ready-made clothes 71 Recommended Dietary Allowances (RDAs) 30 regulatory functions, nutrients in 23 relationships, food in 13 restricted food intake, health risks of 95–96 restricting type anorexia nervosa 105, 106t, 107–108 reverse anorexia 149 reward, food as 12 Russell, Gerald 124

S

safety, of weight-loss products 60 satiety 42, 43–45, 44 saturated fats 28 selective eating disorder 144–145 self-control, need for 60–61 self-esteem body image and 63, 77, 127 eating disorders and 58–61, 59 self-image, negative, overweight and 93–94 self-induced vomiting. See vomiting, self-induced serotonin 45, 58, 121 Seventeen 73, 75 sexuality, food and 10 skinfold thickness 88, 89 skipping meals 47 snacks 46–47 social impacts, of being overweight 93–94 social interactions, food and 13–14 societal influences, food choice and 16–17 sociocultural factors, eating disorders and 57, 61–63 sports, eating disorders and 149, 150. See also athletes starches 27, 28 starvation 31–33, 32, 95–96, 114 stereotypes 11–12, 93 stimulants, in chocolate 12 structural nutrients 23

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Index subcutaneous fat 88 sugars 27–28

T

teenage girls, low body weight in 95 teen years. See adolescence Tolerable Upper Intake Levels (ULs) 30 toys, body image and 75, 147 triglycerides 28 tryptophan 142 Twiggy 75

U

ULs (Tolerable Upper Intake Levels) 30 undernutrition 31–33 underwater weighing 88 underweight defined 84 health risks of 94–96 unsaturated fats 28


189

V

variety, in diet 46 visceral fat 89, 90–91 vitamins deficiencies of 33 as nutrients 27t, 29 vitamin supplements 31 vomiting, self-induced in ancient Rome 125 in bulimia nervosa 130–131 calories retained after 130 physical effects of 131–132, 132

W

waist circumference 91–92, 92t water, as nutrient 27t, 29 weight. See body weight weight loss, in anorexia nervosa 112, 113 weight loss diets 34 weight-loss products, safety of 60 whales 90 women, eating disorders in 55

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aBout the author Lori a. sMoLin, ph.d., received her B.S. degree from Cornell University, where she studied human nutrition and food science. She received her doctorate from the University of Wisconsin at Madison. Her doctoral research focused on B vitamins, homocysteine accumulation, and genetic defects in homocysteine metabolism. She completed postdoctoral training both at the Harbor–UCLA Medical Center, where she studied human obesity, and at the University of California at San Diego, where she studied genetic defects in amino acid metabolism. She has published in these areas in peer-reviewed journals. She and Mary Grosvenor are coauthors of several well-respected college-level nutrition textbooks and contributing authors for a middle school text. Dr. Smolin is currently at the University of Connecticut, where she teaches in the Department of Nutritional Science. Courses she has taught include introductory nutrition, life-cycle nutrition, food preparation, nutritional biochemistry, general biochemistry, and introductory biology. MarY B. grosvenor, M.s., r.d., received her B.A. degree in English from Georgetown University and her M.S. in nutrition sciences from the University of California at Davis. She is a registered dietitian (R.D.) with experience in public health, clinical nutrition, teaching, and nutrition research. She has published in peer-reviewed journals in the areas of nutrition and cancer and methods of assessing dietary intake. She and Lori Smolin are the coauthors of several well-respected college-level nutrition textbooks and contributing authors for a middle school text. Grosvenor has taught introductory nutrition to community college and nursing school students. In addition to writing and teaching she works as a hospital dietitian and certified diabetes educator counseling patients and advises other health professionals in the area of clinical nutrition.

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Eating Disorders