Obesity: Epidemiology, Pathophysiology, and Prevention

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Author: Debasis Bagchi | Harry G. Preuss

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3802_C000.fm Page i Tuesday, January 30, 2007 9:37 AM

CRC Series in Modern Nutrition Science

Obesity Epidemiology, Pathophysiology, and Prevention

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CRC Series in Modern Nutrition Science Series Editor Stacey J. Bell Ideasphere, Inc. Grand Rapids, Michigan

Phytopharmaceuticals in Cancer Chemoprevention Edited by Debasis Bagchi and Harry G. Preuss Handbook of Minerals as Nutritional Supplements Robert A. DiSilvestro Intestinal Failure and Rehabilitation: A Clinical Guide Edited by Laura E. Matarese, Ezra Steiger, and Douglas L. Seidner Nutrition and Wound Healing Edited by Joseph A. Molnar A Clinical Guide for Management of Overweight and Obese Children and Adults Edited by Caroline M. Apovian and Carine M. Lenders Obesity: Epidemiology, Pathophysiology, and Prevention Edited by Debasis Bagchi and Harry G. Preuss

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CRC Series in Modern Nutrition Science

Obesity Epidemiology, Pathophysiology, and Prevention EDITED BY

Debasis Bagchi Harry G. Preuss

Boca Raton London New York

CRC Press is an imprint of the Taylor & Francis Group, an informa business

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CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2007 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S. Government works Printed in the United States of America on acid-free paper 10 9 8 7 6 5 4 3 2 1 International Standard Book Number-10: 0-8493-3802-6 (Hardcover) International Standard Book Number-13: 978-0-8493-3802-1 (Hardcover) This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. No part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, please access www.copyright.com (http:// www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC) 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and registration for a variety of users. For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe. Library of Congress Cataloging-in-Publication Data Obesity : epidemiology, pathophysiology, and prevention / edited by Debasis Bagchi and Harry G. Preuss. p. ; cm. -- (CRC series in modern nutrition science) “A CRC title.” Includes bibliographical references and index. ISBN-13: 978-0-8493-3802-1 (hardcover : alk. paper) ISBN-10: 0-8493-3802-6 (hardcover : alk. paper) 1. Obesity--Epidemiology. 2. Obesity--Pathophysiology. I. Bagchi, Debasis. II. Preuss, Harry G. III. Series. [DNLM: 1. Obesity--therapy. 2. Dietary Supplements. 3. Obesity--physiopathology. 4. Weight Loss--drug effects. WD 210 O1121949 2007] RC645.O23O2465 2007 616.3’98--dc22 Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com

2006102265

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Dedication Dedicated to my beloved father, the late Tarak Chandra Bagchi, and my beloved father-in-law, the late Nakuleshwar Bardhan. –Debasis Bagchi Dedicated to my teachers, especially the late Rachel B. Lott (third grade), the late MSG Thomas Hannon (CCD), and the late Dr. Robert F. Pitts (postdoctoral training). They along with many others prepared me for my career. –Harry G. Preuss

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Contents Preface .............................................................................................................................................. xi Editors ............................................................................................................................................ xiii Contributors......................................................................................................................................xv

PART I Introduction 1

Epidemiology of Obesity .......................................................................................................3 Giovanna Turconi and Hellas Cena

2

Epidemiology of Obesity: A Global Burden for the New Millennium..............................21 Gopal C. Pain

PART II Pathophysiology of Obesity 3

Environmental Estrogens, Endocrine Disruption, and Obesity...........................................33 Frederick S. vom Saal, James R. Kirkpatrick, and Benjamin L. Coe

4

Cigarette Smoking, Inflammation, and Obesity ..................................................................43 Saibal K. Biswas, Ian L. Megson, Catherine A. Shaw, and Irfan Rahman

5

Disordered Eating as a Correlate in the Development of Obesity .....................................63 Gwendolyn W. Pla

6

Role of Neurotransmitters in Obesity Regulation...............................................................71 Sunny E. Ohia and Catherine A. Opere

7

Neurobiology of Obesity .....................................................................................................81 Nina Eikelis

8

Leptin as a Vasoactive Adipokine: Link Between Metabolism and Vasculature ...............93 Anne Bouloumié, Cyrile Anne Curat, Alexandra Miranville, Karine Lolmède, and Coralie Sengenès

9

Overview of Ghrelin, Appetite, and Energy Balance........................................................105 Rafael Fernández-Fernández and Manuel Tena-Sempere

10

Molecular Genetics of Obesity Syndrome: Role of DNA Methylation ...........................115 Rama S. Dwivedi, Atul Sahai, and Bernard L. Mirkin vii

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Obesity: Epidemiology, Pathophysiology, and Prevention

PART III Obesity and Degenerative Diseases 11

Oxidative Stress Status in Humans with Metabolic Syndrome ........................................123 Chung-Yen Chen and Jeffrey B. Blumberg

12

Obesity and Type 2 Diabetes.............................................................................................139 Subhashini Yaturu and Sushil K. Jain

13

Angiogenesis-Targeted Redox-Based Therapeutics ..........................................................155 Shampa Chatterjee, Debasis Bagchi, Manashi Bagchi, and Chandan K. Sen

14

Obesity as an Occult Risk Factor for Drug and Chemical Toxicities ..............................165 George B. Corcoran

PART IV Novel Concept in Obesity Drug Development 15

Adipose Drug Targets for Obesity Treatment ...................................................................177 Olivier Boss, Lorenz Lehr, and Jean-Paul Giacobino

PART V Safety of Obesity Drugs 16

Safety of Obesity Drugs ....................................................................................................199 Alok K. Gupta and Frank L. Greenway

PART VI Natural, Nutritional, and Physical Approaches to Weight Management 17

The Fundamental Role of Physical Activity and Exercise in Weight Management ........219 Dawn Blatt and Cheri L. Gostic

18

Nutritional and Dietary Approaches for Weight Management: An Overview .................233 Sanjiv Agarwal

19

Gender Differences in Body Fat Utilization during Weight Gain, Loss, or Maintenance.......................................................................239 Gabriel Keith Harris and David J. Baer

20

Appetite, Body Weight, Health Implications of a Low-Glycemic-Load Diet..................245 Stacey J. Bell, Wendy Van Ausdal, and Greg Grochoski

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Contents

21

ix

Beyond Obesity Prevention: The Anti-Aging Effects of Caloric Restriction...................265 Kurt W. Saupe and Jacob D. Mulligan

22

Dietary Supplement Carbohydrate Digestion Inhibitors: A Review of the Literature .....279 Jay Udani, Mary Hardy, and Ben Kavoussi

23

Vegetarian Diets in the Prevention and Treatment of Obesity .........................................299 Kathryn T. Knecht, Hien T. Bui, Don K. Tran, and Joan Sabaté

24

The Atkins Paradigm .........................................................................................................315 Ariel Robarge and Bernard W. Downs

25

Polyphenols from Fruits and Vegetables in Weight Management and Obesity Control .....321 Dilip Ghosh and Margot A. Skinner

26

Chromium (III) in Promoting Weight Loss and Lean Body Mass...................................339 Manashi Bagchi, Harry G. Preuss, Shirley Zafra-Stone, and Debasis Bagchi

27

An Overview on (–)-Hydroxycitric Acid in Obesity Regulation......................................349 Shirley Zafra-Stone, Manashi Bagchi, Harry G. Preuss, Gary J. Grover, and Debasis Bagchi

28

A Review of the Safety and Efficacy of Citrus aurantium in Weight Management .......371 Sidney J. Stohs and Michael Shara

29

Conjugated Linoleic Acid and Weight Control: From the Biomedical Immune Viewpoint .........................................................................383 Zwe-Ling Kong

30

The Role of Tea in Weight Management ..........................................................................401 Chithan Kandaswami

31

Laboratory and Clinical Studies of Chitosan ....................................................................413 Harry G. Preuss, Debasis Bagchi, and Gilbert R. Kaats

32

Phaseolus vulgaris and α-Amylase Inhibition..................................................................423 Dennis E. Meiss

33

Glucomannan in Weight Loss: A Review of the Evidence...............................................433 Barbara Swanson and Joyce K. Keithley

34

Role of Caralluma fimbriata in Weight Management ......................................................443 Ramasamy V. Venkatesh and Ramaswamy Rajendran

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35


Role of Medium-Chain Triglycerides in Weight Management.........................................451 Mary G. Enig

36

Anti-Obesity by Marine Lipids .........................................................................................463 Kazuo Miyashita

37

Dairy Foods, Calcium, and Weight Management .............................................................477 Michael B. Zemel

38

Lessons from the Use of Ephedra Products as Dietary Supplements ..............................495 Madhusudan G. Soni, Kantha Shelke, and Rakesh Amin

39

Dietary Supplementation in Weight Loss: A Dietitian’s Perspective ...............................507 Betty Wedman-St. Louis

PART VII Child Obesity and Prevention 40

Treatment and Prevention of Childhood Obesity and Associated Metabolic Diseases..... 515 Michael I. Goran, Jaimie N. Davies, and Louise A. Kelly

PART VIII Bariatric Surgery in Weight Management 41

Bariatric Surgery in Obesity and Reversal of Metabolic Disorders .................................531 Melania Manco

Index ..............................................................................................................................................545

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Preface The spread of obesity has been declared a worldwide epidemic by the World Health Organization (WHO). In fact, a new term, globesity, has been coined to describe the recent upsurge of overweight and obesity throughout the world’s population. How severe is the problem? According to WHO, more than 1 billion adults are overweight and at least 315 million are clinically obese. To make matters worse, the International Obesity Task Force estimates that 22 million of the world’s children under age of 5 are overweight or obese [1–4]. In addition to type 2 diabetes, obesity has also been linked to other broad-spectrum, degenerative diseases, including other metabolic disorders and certain forms of cancer. Among the children diagnosed with type 2 diabetes, 85% are obese [2]. It has been reported that 80% of type 2 diabetes, 70% of cardiovascular diseases, and 42% of breast and colon cancers are related to obesity [1,2]. Obesity is the major factor behind 30% of gallbladder perturbations leading to surgery and 26% of incidences of high blood pressure. The unfortunate outcome of globesity has generated an unlimited array of weight-loss strategies [1,2]. Products and programs that induce rapid weight loss and disturb metabolic homeostasis dominate the focus of marketers and consumers alike; however, rapid weight loss is potentially unhealthy and frequently induces undesirable rebound weight gain consequences. In addition, many anti-obesity pharmaceuticals are accompanied by adverse reactions, making the cure worse than the disorder itself; thus, it is very important to develop a strategic therapeutic intervention using safe, novel, natural supplements supported by credible research. This book, intended for practicing medical professionals, clinical nutritionists, dietitians, and researchers, addresses many issues relevant to obesity: the molecular mechanisms and pathophysiology leading to obesity and metabolic disorders, the safety of obesity drugs, drug development strategies, the influences of physical activity and nutrition, and the benefits of research-supported nutraceutical supplements. The forty-one chapters in this book have been written by experts in their fields. A worldrenowned nutritionist and a health professional have provided a world overview of the epidemiology of obesity in the first part. Part II demonstrates the pathophysiology of obesity and correlates obesity with environmental estrogens, endocrine disruption, inflammatory responses, tobacco, disordered eating, and neurobiology and neurotransmitters. The significance of the hunger hormone ghrelin, leptin, and the molecular genetics of obesity syndrome are discussed in subsequent chapters. Part III correlates obesity with diverse degenerative diseases, including metabolic syndrome, type 2 diabetes, and cancer. Dr. Olivier Boss, a lead researcher on adipose drug targets, addresses new concepts in obesity drug development in Part IV. Pennington Biomedical Research Center scientists discuss the safety of obesity drugs in Part V, and Part VI summarizes natural, nutritional, and physical approaches to weight management. The roles of physical activity, healthy dietary approaches, gender effects, and caloric restriction are thoroughly explored, and this part also provides a thorough discussion of carbohydrate blockers, polyphenolic compounds, trivalent chromium, Garcinia cambogia, (–)-hydroxycitric acid, Citrus aurantium, Caralluma fimbriata, Phaseolus vulgaris, α-amylase inhibition, conjugated linoleic acid, tea, chitosan, glucomannan, marine lipids, calcium and dairy products, and medium-chain triglycerides. Also included is a chapter on the Atkins paradigm, a chapter on the banned weight-loss supplement ephedra (which ruled the market for at least a decade), and, finally, a chapter offering the reflections of a practicing dietitian regarding weight-loss supplements. Part VII examines the complicated problem of childhood obesity, including metabolic acidosis, and provides an intervention strategy. Part VIII demonstrates how bariatric surgery can help in weight management and reversing metabolic disorders. Finally, we extend our special thanks to all the authors for their invaluable contributions.

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REFERENCES 1. Worldwide Obesity: Trends Global Obesity Trends, Globesity the Growing Epidemic of Chronic Overweight, 2006, http://www.annecollins.com/obesity/worldwide-obesity.htm. 2. Obesity Statistics: Weight Statistics — Adults, Children, Obesity-Related Diseases, 2006, http://www.annecollins.com/obesity/statistics-obesity.htm. 3. WHO, World Health Statistics, World Health Organization, Geneva, 2006, pp. 42–48. 4. NCHS, Health, United States 2005, National Center for Health Statistics, Hyattsville, MD, 2005.

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Editors Debasis Bagchi, Ph.D., FACN, CNS, MAIChE, received his Ph.D. in medicinal chemistry in 1982. He is a professor of toxicology in the Department of Pharmacy Sciences at Creighton University Medical Center, Omaha, Nebraska. Dr. Bagchi is also the senior vice president of research and development at InterHealth Nutraceuticals, Inc., in Benicia, California. Dr. Bagchi is the vice president of the American College of Nutrtion and chair-elect of the Nutraceuticals and Functional Foods division of the Institute of Food Technologists (IFT). His research interests include free radicals, human diseases, carcinogenesis pathophysiology, mechanistic aspects of cytoprotection by antioxidants, regulatory pathways in obesity, and gene expression. Dr. Bagchi has written 225 papers that have been published in peer-reviewed journals. He has delivered invited lectures and served as session chairperson for various national and international scientific conferences, organized workshops, and group discussion sessions. Dr. Bagchi is a fellow of the American College of Nutrition, member of the Society of Toxicology, member of the New York Academy of Sciences, fellow of the Nutrition Research Academy, and member of the TCE Stakeholder Committee of the Wright Patterson Air Force Base, Ohio. Dr. Bagchi is a member of the Study Section and Peer Review Committee of the National Institutes of Health, Bethesda, Maryland, and serves as a reviewer of U.S. Army research grants on Gulf War Illness. Dr. Bagchi is also serving as editorial board member of numerous peer-reviewed journals, including Antioxidants and Redox Signaling, Toxicology Letters, The Original Internist, Research Communications in Pharmacology and Toxicology, and the International Journal of Geriatric Urology and Nephrology. Dr. Bagchi has received research funding from various institutions and agencies, including the U.S. Air Force Office of Scientific Research; National Institutes of Health (NIH); National Cancer Institute (NCI); National Heart, Lung, and Blood Institute (NHLBI); American Heart Association; Nebraska State Department of Health, Biomedical Research Support Grant; Health Future Foundation; The Procter & Gamble Company; and Abbott Laboratories. Harry G. Preuss, M.D., MACN, CNS, received his B.A. and M.D. from Cornell University, trained for 3 years in internal medicine at Vanderbilt University Medical Center under Dr. David E. Rogers, studied for 2 years as a fellow in renal physiology at Cornell University Medical Center under Dr. Robert F. Pitts, and spent 2 years in clinical and research training in nephrology at Georgetown University Medical Center under Dr. George E. Schreiner. During his training years, he was a special research fellow of the National Institutes of Health (NIH) and an established investigator of the American Heart Association. Following 5 years as an assistant and associate (tenured) professor of medicine at the University of Pittsburgh Medical Center, he returned to Georgetown Medical Center and is now a professor of physiology, medicine, and pathology (tenured). He subsequently performed a 6-month sabbatical in molecular biology at the NIH in the laboratories of Dr. Maurice Burg. His bibliography includes over 300 medical papers and more than 200 abstracts. Dr. Preuss has edited or co-edited seven books and three symposia published in wellestablished journals. He is the co-author of three books written for the lay public: The Prostate Cure, Maitake Magic, and the recently published The Natural Fat-Loss Pharmacy. He is currently an advisory editor for six journals. In 1976, Dr. Preuss was elected to membership in the American Society of Clinical Investigations. His previous government appointments included 4 years on the Advisory Council for the National Institute on Aging, 2 years on the Advisory Council of the director of the NIH, and 2 years on the Advisory Council for the Office of Alternative Medicine of the NIH. He has been a member of many other peer research review committees for the NIH

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and American Heart Association and is now a member of the National Cholesterol Education Program of the NHLBI. Dr. Preuss was elected the ninth Master of the American College of Nutrition (ACN). He is a former chairman of two ACN councils: the Cardiovascular and Aging Council and the Council on Dietary Supplements, Nutraceuticals, and Functional Foods. After a brief stint on the Board of Directors of the ACN, Dr. Preuss spent 3 years as secretary–treasurer and 3 consecutive years as vice president, president-elect, and president. He is currently chairman of the Nutritional Policy Institute of the ACN. Dr. Preuss is a member of the board of directors for the American Association for Health Freedom (AAHF) and was their treasurer. Dr. Preuss wrote the nutrition section for the Encyclopedia Americana and for seven years was president of the Certification Board for Nutrition Specialists (CBNS) that gives the CNS certification. He is cochairman of the Institutional Review Board (IRB) at Georgetown University, which reviews all clinical protocols at Georgetown University Medical Center. His research centers on the use of dietary supplements and nutraceuticals to favorably influence or even prevent a variety of medical perturbations, especially those related to obesity, insulin resistance, and cardiovascular perturbations. Lately, he has also researched the ability of many oils and fats to overcome various infections, including those resistant to antibiotics.

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Contributors Sanjiv Agarwal ConAgra Foods, Inc. Omaha, Nebraska

Olivier Boss Sirtris Pharmaceuticals, Inc. Cambridge, Massachusetts

Rakesh Amin Amin Law, LLC Chicago, Illinois

Anne Bouloumié AVENIR INSERM U586, Obesity Research Unit Paul Sabatier University Louis Bugnard Institute IFR31 Toulouse, France

David J. Baer Diet and Human Performance Laboratory Beltsville Human Nutrition Research Center Beltsville, Maryland Debasis Bagchi Department of Pharmacy Sciences Creighton University Medical Center Omaha, Nebraska; InterHealth Research Center Benicia, California Manashi Bagchi InterHealth Research Center Benicia, California Stacey J. Bell IdeaSphere, Inc. Grand Rapids, Michigan Saibal K. Biswas Department of Biochemistry Dr. Ambedkar College Deeksha Bhoomi, Nagpur, India Dawn Blatt Division of Rehabilitation Sciences School of Health Technology and Management Stony Brook University Stony Brook, New York Jeffrey B. Blumberg Antioxidants Research Laboratory Jean Mayer U.S.D.A. Human Nutrition Research Center on Aging Tufts University Boston, Massachusetts

Hien T. Bui School of Pharmacy Loma Linda University Loma Linda, California Hellas Cena Department of Applied Health Sciences Section of Human Nutrition and Dietetics Faculty of Medicine University of Pavia Pavia, Italy Shampa Chatterjee University of Pennsylvania School of Medicine Philadelphia, Pennsylvania Chung-Yen Chen Antioxidant Research Laboratory Jean Mayer U.S.D.A. Human Nutrition Research Center on Aging Tufts University Boston, Massachusetts Benjamin L. Coe Division of Biological Sciences University of Missouri–Columbia Columbia, Missouri George B. Corcoran Department of Pharmaceutical Sciences Eugene Applebaum College of Pharmacy and Health Sciences Wayne State University Detroit, Michigan

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Cyrile Anne Curat Cardiovascular Physiology Institute Frankfurt/Main, Germany Jaimie N. Davies Department of Preventive Medicine Keck School of Medicine University of Southern California Los Angeles, California Bernard W. Downs Allied Nutraceutical Research Lederach, Pennsylvania Rama S. Dwivedi Department of Pediatrics and Molecular Pharmacology and Biological Chemistry Children’s Memorial Research Center The Feinberg School of Medicine Northwestern University Chicago, Illinois

Michael I. Goran Department of Preventive Medicine Keck School of Medicine University of Southern California Los Angeles, California Cheri L. Gostic Division of Rehabilitation Sciences School of Health Technology and Management Stony Brook University Stony Brook, New York Frank L. Greenway Medical Director and Professor Pennington Biomedical Research Center Louisiana State University System Baton Rouge, Louisiana Greg Grochoski Research and Development IdeaSphere, Inc. Grand Rapids, Michigan

Nina Eikelis Human Neurotransmitter Laboratory Baker Heart Research Institute Melbourne, Australia

Gary J. Grover Eurofins Scientific Dayton, New Jersey

Mary G. Enig Nutritional Sciences Division Enig Associates, Inc. Silver Spring, Maryland

Alok K. Gupta Pennington Biomedical Research Center Louisiana State University System Baton Rouge, Louisiana

Rafael Fernández-Fernández Department of Cell Biology, Physiology, and Immunology University of Córdoba Córdoba, Spain Dilip Ghosh Health and Food Group The Horticulture and Food Research Institute of New Zealand Ltd. Auckland, New Zealand

Mary Hardy Integrative Medicine Group, Cedars-Sinai Medical Center UCLA Center for Dietary Supplement Research in Botanicals UCLA Center for Human Nutrition Department of Medicine, David Geffen/UCLA School of Medicine UCLA Collaborative Centers for Integrative Medicine Los Angeles, California

Jean-Paul Giacobino Growth and Development Laboratory Rangos Research Center Pittsburgh, Pennsylvania

Gabriel Keith Harris Diet and Human Performance Laboratory Beltsville Human Nutrition Research Center Beltsville, Maryland

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Contributors

Sushil K. Jain Department of Pediatrics Louisiana State University Health Sciences Center Shreveport, Louisiana Gilbert R. Kaats Health and Research Foundation San Antonio, Texas Chithan Kandaswami ADVOCARE International Carrollton, Texas Ben Kavoussi Medicus Research, LLC Northridge, California Joyce K. Keithley Adult Health Nursing Rush University College of Nursing Chicago, Illinois Louise A. Kelly Department of Preventive Medicine Keck School of Medicine University of Southern California Los Angeles, California James R. Kirkpatrick Division of Biological Sciences University of Missouri–Columbia Columbia, Missouri Kathryn T. Knecht Department of Pharmaceutical Science School of Pharmacy Loma Linda University Loma Linda, California Zwe-Ling Kong Cellular Immunology Lab Department of Food Science National Taiwan Ocean University Taiwan, Republic of China

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Lorenz Lehr Department of Cell Physiology and Metabolism University of Geneva Medical School Geneva, Switzerland Karine Lolmède Cardio-Thoracic and Vascular Department University Vita-Salute San Raffaele Milano, Italy Melania Manco Liver Unit Bambino Gesù Paediatric Hospital and Research Institute Rome, Italy Ian L. Megson Free Radical Research Facility Department of Diabetes UHI Millennium Institute Inverness, United Kingdom Dennis E. Meiss ProThera®, Inc. Reno, Nevada Alexandra Miranville Cardiovascular Physiology Institute Frankfurt/Main, Germany Bernard L. Mirkin Department of Pediatrics and Molecular Pharmacology and Biological Chemistry Children’s Memorial Research Center The Feinberg School of Medicine Northwestern University Chicago, Illinois Kazuo Miyashita Hokkaido University Hakodate, Japan Jacob D. Mulligan Departments of Medicine University of Wisconsin–Madison Madison, Wisconsin

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Sunny E. Ohia Department of Pharmacological and Pharmaceutical Sciences College of Pharmacy University of Houston Houston, Texas Catherine A. Opere Department of Pharmacy Sciences School of Pharmacy and Health Professions Creighton University Medical Center Omaha, Nebraska Gopal C. Pain National Consultant of India World Health Organization New Delhi, India Gwendolyn W. Pla Department of Nutritional Sciences Howard University Washington, D.C. Harry G. Preuss Georgetown University Medical Center Washington, D.C. Irfan Rahman Department of Environmental Medicine Division of Lung Biology and Disease University of Rochester Medical Center Rochester, New York Ramaswamy Rajendran Green Chem Bangalore, India Ariel Robarge Department of Nutrition Rothman Institute Philadelphia, Pennsylvania Joan Sabaté Department of Nutrition School of Public Health Loma Linda University Loma Linda, California

Atul Sahai National Institute of Diabetes and Digestive and Kidney Diseases National Institutes of Health Bethesda, Maryland Kurt W. Saupe Departments of Medicine and Physiology University of Wisconsin–Madison Madison, Wisconsin Chandan K. Sen The Ohio State University Medical Center Columbus, Ohio Coralie Sengenès AVENIR INSERM U586, Obesity Research Unit Paul Sabatier University Louis Bugnard Institute IFR31 Toulouse, France Michael Shara School of Pharmacy and Health Professions Creighton University Medical Center Omaha, Nebraska Catherine A. Shaw Centre for Cardiovascular Sciences Queen’s Medical Research Institute University of Edinburgh Edinburgh, United Kingdom Kantha Shelke Corvus Blue, LLC Chicago, Illinois Food Processing & Wellness Foods magazine Itasca, Illinois Margot A. Skinner Health and Food Group The Horticulture and Food Research Institute of New Zealand Ltd. Auckland, New Zealand Madhusudan G. Soni Soni and Associates Vero Beach, Florida

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Contributors

Sidney J. Stohs ADVOCARE International Carrollton, Texas Barbara Swanson Adult Health Nursing Rush University College of Nursing Chicago, Illinois Manuel Tena-Sempere Department of Cell Biology, Physiology, and Immunology University of Córdoba Córdoba, Spain Don K. Tran School of Pharmacy Loma Linda University Loma Linda, California Giovanna Turconi Department of Applied Health Sciences Section of Human Nutrition and Dietetics Faculty of Medicine University of Pavia Pavia, Italy Jay Udani David Geffen/UCLA School of Medicine Integrative Medicine Program, Northridge Hospital Medicus Research, LLC Northridge, California

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Wendy Van Ausdal IdeaSphere, Inc. American Fork, Utah Ramasamy V. Venkatesh Gencor Pacific Limited Discovery Bay, Hong Kong Frederick S. vom Saal Division of Biological Sciences University of Missouri–Columbia Columbia, Missouri Betty Wedman-St. Louis New York Chiropractic College and University of Phoenix Licensed Nutritionist and Environmental Health Specialist St. Petersburg, Florida Subhashini Yaturu Overton Brooks Veterans Administration Medical Center Louisiana State University Health Sciences Center Shreveport, Louisiana Shirley Zafra-Stone InterHealth Research Center Benicia, California Michael B. Zemel The University of Tennessee Nutrition Institute The University of Tennessee Knoxville, Tennessee

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Part I Introduction

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1 Epidemiology of Obesity Giovanna Turconi and Hellas Cena CONTENTS Introduction ........................................................................................................................................3 Prevalence of Obesity in the Adult Population .................................................................................5 Europe .........................................................................................................................................6 United States ...............................................................................................................................8 Latin America and Caribbean...................................................................................................10 Africa ........................................................................................................................................10 Japan, China, and Western Pacific Countries...........................................................................10 Prevalence of Obesity in Children and Adolescents .......................................................................11 Europe .......................................................................................................................................11 United States .............................................................................................................................13 Australia and China ..................................................................................................................14 Health Consequences of Obesity and Morbidity ............................................................................14 Benefits of Weight Loss...................................................................................................................14 Economic Costs of Obesity .............................................................................................................15 The Need for Action ........................................................................................................................16 References ........................................................................................................................................17

INTRODUCTION Obesity is a complex, multifactorial, chronic disease involving environmental (social and cultural), genetic, physiologic, metabolic, behavioral, and psychological components. It has been increasing at an alarming rate throughout the world over the past two decades to the extent that it is now a pandemic, affecting millions of people globally, and it is the second leading cause of preventable death in the United States. The World Health Organization (WHO) has estimated that more than 300 million people are obese worldwide [1]. Obesity is defined as a condition of excess body fat, and it is associated with a large number of debilitating and life-threatening disorders, such as major increases in associated cardiovascular, metabolic, and other noncommunicable diseases [2]. It also contributes to increased mortality rates from all causes, including cardiovascular diseases (CVDs) and cancer. The obesity prevalence rate increase is evident in Westernized countries, where obesity has been present for decades, but today it is also particularly noticeable in less developed countries that previously had not experienced problems with overweight and obesity. For example, the prevalence of obesity has increased by about 10 to 40% in the majority of European countries in the last decade, and it currently affects nearly one third of the adult American population, as well as three quarters of the adult population living in urban areas of Western Samoa in the Pacific [3]. Obesity in the developing world reflects the profound changes in society over the past 20 to 30 years that have created an environment that promotes a sedentary lifestyle and the consumption of a high-fat, energy-dense diet, collectively known as the nutrition transition. As poor countries

3


4


From least to most developed countries: overweight is on the rise Percentage of population 25

20

Underweight Overweight

15

10

5

0 Global

Least developed countries

Developing countries

Economies in transition

Developed market economy countries

As countries develop, they face many of the problems common in industrialized nations. Obesity is one of the most worrisome.

FIGURE 1.1 From least to most developed countries, overweight is on the rise. As countries develop, they face many of the problems common to industrialized nations. Obesity is one of the most worrisome. (From FAO, The Developing World’s New Burden: Obesity, Food and Agriculture Organization, United Nations, Geneva, Switzerland, 2002, http://www.fao.org/FOCUS/E/obesity/obes2.htm.)

become more prosperous, they acquire some of the benefits as well as some of the problems of industrialized nations, including obesity (Figure 1.1) [4]. Because the direct measurement of body fat is difficult, the body mass index (BMI), a simple weight-to-height ratio (kg/m2), is typically used to classify overweight and obese adults. Consistent with this, the WHO has recently published international standards for classifying overweight and obesity in adults (Table 1.1). Obesity is defined as a BMI ≥ 30 kg/m2, but it can be further subdivided on the basis of the severity of the obesity [1].

TABLE 1.1 WHO Standard Classification of Obesity Classification Normal range Overweight Obesity class I Obesity class II Obesity class III

BMI (kg/m2)

Risk of Comorbidities

18.5–24.9 25.0–29.9 30.0–34.9 35.0–39.9 ≥40

Average Mildly increased Moderate Severe Very severe

Source: WHO, Obesity: Preventing and Managing the Global Epidemic, Report of a WHO Consultation, World Health Organization, Geneva, Switzerland, 2000, p. 256.


Epidemiology of Obesity

5

TABLE 1.2 Sex-Specific Waist Circumferences for Increased Risk and Substantially Increased Risk of Metabolic Complications Associated with Obesity in Caucasians Risk of Obesity-Associated Metabolic Complications

Men Women

Increased

Substantially Increased

≥94 cm ≥80 cm

≥102 cm ≥88 cm

Note: The figures are population-specific and the relative risk also depends on levels of obesity (BMI) and other risk factors for CVD and NIDDM. Source: WHO, Obesity: Preventing and Managing the Global Epidemic, Report of a WHO Consultation, World Health Organization, Geneva, Switzerland, 2000, p. 256.

Although the BMI provides a simple, convenient measurement of obesity, a more important aspect of obesity is the regional distribution of excess body fat. Visceral or intraabdominal obesity, in contrast to subcutaneous or lower body obesity, carries the greatest risk of a number of chronicdegenerative diseases, including CVD and non-insulin-dependent diabetes mellitus (NIDDM). The importance of central obesity is clear in populations (e.g., Asian) that tend to have relatively low BMI values but high levels of abdominal fat and are particularly prone to NIDDM, hypertension, and CVD. Methods for evaluating abdominal fat include measuring waist circumference. Changes in waist circumference reflect changes in risk for CVD and other chronic diseases. As with the BMI, cut-off values have been set to identify increased risk, but for waist circumference these must be sex and population specific (Table 1.2) [1]. We must still recognize that overweight and obesity are part of a continuum and that health risks increase with increasing weight in the individual. It has been estimated that the costs of obesity account for up to 8% of the total healthcare costs in Western countries, and they represent an enormous burden with regard to individual illness, disability, and early mortality as well as in terms of the costs to employers, taxpayers, and society. The mortality associated with excess weight increases as the degree of obesity and overweight increases. One study estimated that between 280,000 and 325,000 deaths annually in the United States could be attributed to overweight and obesity [5]. More than 80% of these deaths occur among people with a BMI > 30 kg/m2. The increase in deaths due to obesity has been documented in a number of studies from around the world (Table 1.3) [6–10].

PREVALENCE OF OBESITY IN THE ADULT POPULATION It should be noted that it is often difficult to make a direct comparison of the prevalence of obesity among countries due to the inconsistent classifications used to define obesity. This problem may be overcome with the adoption in future surveys of the WHO standardized classifications for obesity. From available data, the worldwide prevalence of obesity has been found to range from less than


6


TABLE 1.3 All-Cause and Disease-Specific Cause of Death from Several Epidemiological Studies in Relation to Body Mass Index All-Cause Mortality (Deaths/1000 Patient-Years) Study and BMI Criteria (kg/m2)

Male

Female

Nurses Health Study (ages 30–55 years, with 16 years’ follow-up) [7] 19.0–21.9 — 2.46 22.0–24.9 — 2.46 25.0–26.9 — 2.61 27–28.9 — 3.35 29–31.9 — 3.90 >32 — 4.64 British Regional Heart Study (ages 40–59 years, with 13.8 years’ follow-up) [8] 20–21.9 12.6 — 22–23.9 11.5 — 24–25.9 11.8 — 26–27.9 11.8 — 28–29.9 13.3 — >30 16.8 — Gothenberg Birth Cohort (ages 47–55 years, with 19.7 years’ follow-up) [9] 20.0–22.5 15.5 — 22.5–25.0 13.9 — 25.0–27.5 14.3 — 27.5–30 16.6 — >30 21.1 — Cancer Prevention Study II (ages 65–74 years) [10] 22.0–23.4 8.54 23.5–24.9 8.98 25.0–26.4 9.41 26.5–27.9 10.38 28.0–29.9 12.70 30.0–31.9 13.70 32.0–34.9 17.98 >35 27.67

4.98 5.95 5.98 6.36 7.96 8.36 11.11 12.99

Source: Caterson, J.D. et al., Circulation, 110, e476–e483, 2004. With permission.

5% in rural China, Japan, and some African countries to levels as high as 75% of the adult population in urban Samoa. Table 1.4 [3] provides examples of secular trends of obesity for various countries. Obesity levels also vary depending on ethnic origin. In the United States, particularly among women, large differences exist in the prevalence of obesity among populations of different ethnic origins within the same country.

EUROPE Obesity is relatively common in Europe, especially among women and in Southern and Eastern European countries. A marked trend toward increasing levels of adult overweight and obesity can be found throughout Europe, although prevalence rates differ. Current prevalence data from a report



7

TABLE 1.4 Secular Trends of Obesity Worldwide (BMI > 30) Country

Year

Ages

Men

Women

Australia Brazil

1989 1975 1989 1991 1989 1991 1992 1988 1989 1992 1980 1986–1987 1991–1992 1995 1987–1988 1982 1987 1993 1994 1992 1998 1990–1993

20–69 25–64

9.3 3.1 5.9 15 0.29 0.36 1.20 16 13 21 6 7 13 15 0.9 0.9 1.3 1.8 32 10 13.5

11.1 8.2 13.3 15 0.89 0.86 1.64 20 21 27 8 12 15 16.5 — 2.6 2.8 2.6 44 10 11.7

18 12 8 10 11.6 12.0 19.7 16 17.7 41.5 38.8 58.4

28 18 44 11 16.1 14.8 24.7 21 37.0 59.2 59.1 76.8

Canada China

Czech Republic East Germany England

Ghana Japan

Kuwait Quebec Saudi Arabia Urban Rural South Africa Cape Peninsular The Netherlands United States

West Germany Western Samoa (rural) Western Samoa (urban)

1990 1994 1973 1978 1991 1991 1978 1991 1978 1991

18–74 20–45

20–65 25–65 16–64

20+ 20+

18+ 20–64 15+

15–64 20–59 20–74

25–69 25–69 25–69

Source: WHO, Obesity: Preventing and Managing the Global Epidemic, Report of WHO Consultation on Obesity, World Health Organization, Geneva, 1998.

by the International Obesity Task Force (IOTF) suggest that the obesity prevalence in European countries ranges from 10 to 27% for men and up to 38% for women [11]. Finland, Germany, Greece, Cyprus, the Czech Republic, Slovakia, and Malta all have overweight rates that bypass those of the United States. When judged on obesity alone, at least nine European countries have male obesity rates above 20%, including Greece and Cyprus (27%). The prevalence of obesity has increased by about 10 to 40% in most of the European countries in the last decade. In France, obesity rose from 8.0% to 11.3% in women and from 8.4% to 11.4% in men, based on self-reported surveys conducted between 1997 and 2003. In The Netherlands, obesity rose gradually from 6.2% to 9.3% in women and from 4.9% to 8.5% in men from the late 1970s to the mid-1990s. The most


8


FIGURE 1.2 Prevalence of adult obesity in Europe (BMI ≥ 30 kg/m2). (From Rigby, N. and James, P., Waiting for a Green Light for Health? Europe at the Crossroads for Diet and Disease, IOTF Position Paper, International Obesity Task Force, London, 2003, http://www.iotf.org/media/euobesity2.pdf.)

dramatic increase was recorded in the United Kingdom, where the obesity rate rose from 13.2% to 22.2% in men and from 16.4% to 23.0% in women in just 10 years, up to 2003. Compare these rates to an obesity rate of 6 to 7% in 1980 [11]. Figure 1.2 shows the prevalence of adult obesity in Europe reported by the IOTF in 2003 [12].

UNITED STATES National survey data from the United States show that the prevalence of overweight and obesity among adults remained relatively constant over the 20-year period from 1960 to 1980. It began to increase around the mid-1980s, and the past 25 years have witnessed a dramatic increase. In 1985, only a few states participated in and provided obesity data to the Behavioral Risk Factor Surveillance System (BRFSS) of the Centers for Disease Control and Prevention (CDC). In 1991, 4 states reported obesity prevalence rates of 15 to 19%, and no states had rates at or above 20%. In 2004, 7 states had obesity prevalence rates of 15 to 19%, 33 states had rates of 20 to 24%, and 9 states had rates higher than 25% (no data for one state). A recent IOTF report [11] shows that obesity stands at 28% in men and 34% in women, although this rate rises to as high as 50% among black women and includes a very significant component of morbid obesity. The data shown in Figure 1.3 [13] were collected through the CDC’s BRFSS. Each year, state health departments use standard procedures to collect data through a series of monthly telephone interviews with U.S. adults. Prevalence estimates generated for the maps may vary slightly from those generated for the states by the BRFSS, as slightly different analytic methods are used. It must be noted that overweight and obesity in the United States occur at higher rates among racial or ethnic minority populations, such as African-Americans and Hispanic-Americans, compared with Caucasian Americans. Asian-Americans have a relatively low prevalence for obesity. Women and persons of low socioeconomic status within minority populations appear to be particularly



9 Obesity Trends* Among U.S. Adults BRFSS, 1991, 1996, 2004

(*BMI ≥30, or about 30 lb overweight for 5ʼ4” person) 1991

1996

2004

No Data

25), with rates of 50.9% in Tunisia and 51.3% in Morocco. Obesity rates (BMI > 30) among this population of women are 23% in Tunisia and 18% in Morocco, a threefold increase over 20 years [19]. In parts of Sub-Saharan Africa, obesity often exists alongside undernutrition [20].

JAPAN, CHINA,

AND

WESTERN PACIFIC COUNTRIES

In Japan, obesity in men has doubled since 1982, whereas its rise in women has been restricted to the younger age group (20 to 29 years), for which it has increased 1.8 times since 1976 [3]. Using the obesity cut-off of a BMI > 25 as the standard, adult obesity in Japan would average 20%, rising to 30% in men over 30 years old and in women over 40 years old, thus representing a three- to fourfold increase over the last 40 years [21]. Obesity is increasing in China and is more common in urban areas and among women. Between 1992 and 2002, the prevalence of overweight and obesity increased in all gender and age groups and in all geographic areas. The Chinese obesity standard shows an increase from 20.0% to 29.9%. The annual increase rate was highest in men ages 18 to 44 years and women ages 45 to 59 years (approximately 1.6% and 1.0%, respectively). In general, male subjects, urban residents, and high-income groups had a greater increase [22]. Obesity is not new to the Pacific and has long been regarded by Polynesian and Micronesian societies of this region as a symbol of high social status and prosperity. The prevalence has risen dramatically, however, in the last 20 years. The link between obesity and type 2 diabetes is most manifest in this region, which has some of the highest levels of adult obesity. Obesity prevalence rates of between 60 and 80% can be found among men and women in some islands, including



11

Samoa and Nauru. In Tonga, 60% of the adult population is obese, and recently 12% of men and nearly 18% of women were identified with type 2 diabetes, a doubling of the rate over 25 years. A further 20% were found to be at risk due to elevated blood sugar levels [23].

PREVALENCE OF OBESITY IN CHILDREN AND ADOLESCENTS EUROPE Recent concern has focused on child and adolescent obesity, which is a rapidly growing problem in many countries. The concern is not only that young people who are already overweight and obese are destined to remain so throughout their adult lives with heightened risks to health, but also that youngsters are already developing diseases of old age, such as type 2 diabetes. Surveys show overweight and obesity levels among children in Southern Europe to be higher than their Northern European counterparts as the traditional Mediterranean diet gives way to more processed foods rich in fat, sugar, and salt. The 2005 IOTF European Union platform briefing paper [11] shows that the Mediterranean islands of Malta, Sicily, Gibraltar, and Crete, as well as the countries of Spain, Portugal, and Italy, have reported overweight and obesity levels exceeding 30% among children ages 7 to 11, as illustrated in Figure 1.4 [11]. In addition, England, Ireland, Cyprus, and

Percentage of adolescents ages 7 to 11 obese or overweight Malta Sicily Spain Gibraltar Crete Portugal Italy England Ireland (Republic) Cyprus Sweden Greece France Switzerland Bulgaria Poland Czech Republic Hungary Germany Denmark Netherlands 0

10 obese

20

30

40

oveweight

FIGURE 1.4 Overweight and obesity in adolescents ages 7 to 11. (From Lobstein, T. et al., EU Platform on Diet, Physical Activity and Health, IOTF EU Platform Briefing Paper, in collaboration with EASO, International Obesity Task Force, London, 2005, http://ec.europa.eu/comm/health/ph_determinants/life_style/nutrition/documents/iotf_en.pdf.)


12


Percentage of schoolchildren ages 13 to 17 obese or overweight Crete England Italy Cyprus Ireland (Republic) Greece Bulgaria Spain Denmark Hungary Ireland (Northern) Poland Finalnd Czech Republic Germany Netherlands Slovakia 0

10 obese

20

30

40

oveweight

FIGURE 1.5 Overweight and obesity in children ages 13 to 17. (From Lobstein, T. et al., EU Platform on Diet, Physical Activity and Health, IOTF EU Platform Briefing Paper, in collaboration with EASO, International Obesity Task Force, London, 2005, http://ec.europa.eu/comm/health/ph_determinants/life_style/nutrition/documents/iotf_en.pdf.)

Greece reported levels above 20%, while France, Switzerland, Poland, the Czech Republic, Hungary, Germany, Denmark, The Netherlands, and even Bulgaria reported overweight and obesity levels of 10 to 20% among this same age group [11]. For teenagers (ages 13 to 17), seven countries reported overweight and obesity levels above 20%, with Crete peaking at 35%, as shown in Figure 1.5 [11]. The data in both Figure 1.4 and Figure 1.5 are from available surveys, so comparisons require caution as the survey years may differ. The IOTF’s international standard for analyzing childhood overweight and obesity data has been widely adopted [24]. It provides growth curves that relate cut-off points for different age groups to the adult categories for overweight (BMI ≥ 25 kg/m2) and obesity (BMI ≥ 30 kg/m2). The IOTF method allows more realistic comparisons to be made among data from different countries, whereas other assessment standards often relate to centiles, which indicate arbitrary positions above a BMI centile value for overweight and obesity. Childhood overweight and obesity are accelerating rapidly in some countries. The rise has been particularly marked in recent years. IOTF estimates [11] prepared for WHO suggest that one out of five children in Europe is overweight. An additional 400,000 children each year are becoming overweight, and at least 3 million are obese. Annual increases in prevalence of around 0.2% during the 1970s rose to 0.6% during the 1980s and up to 0.8% in the early 1990s, reaching as high as 2.0% in some cases by the 2000s.



13

TABLE 1.6 Increase in Obesity Prevalence (%) Among U.S. Children (Ages 6 to 11) Years

Boys

Girls

1999 to 2000 1988 to 1994 1971 to 1974

16.0 11.6 4.3

14.5 11.0 3.6

Source: Ogden, C.L. et al., JAMA, 288, 1728–1732, 2002. With permission.

TABLE 1.7 Increase in Obesity Prevalence (%) Among U.S. Adolescents (Ages 12 to 19) Years 1999 to 2000 1988 to 1994 1971 to 1974

Males

Females

15.5 11.3 6.1

15.5 9.7 6.2

Source: Ogden, C.L. et al., JAMA, 288, 1728– 1732, 2002. With permission.

UNITED STATES Overweight and obesity for children and adolescents are defined as being at or above the 85th and 95th percentiles, respectively, of the gender-specific BMI for age growth charts. Approximately 30.3% of children (ages 6 to 11) are overweight, and 15.3% are obese. Among adolescents (ages 12 to 19), 30.4% are overweight and 15.5% are obese. Overweight prevalence is higher in boys (32.7%) than girls (27.8%). In adolescents, overweight prevalence is about the same for females (30.2%) and males (30.5%). The prevalence of obesity quadrupled over 25 years among children, as shown in Table 1.6 [25,26], and more than doubled over 25 years among adolescent males and females, as shown in Table 1.7 [25,26]. With regard to race and ethnicity, African-American, Hispanic-American, and Native American children and adolescents have particularly high obesity prevalence rates. Overweight and obesity prevalence for children and adolescents is presented by racial group in Table 1.8 [25,26]. Among female youth, the highest overweight and obesity prevalence rates are found in black (non-Hispanic) girls (ages 6 to 11; 37.6% and 22.2%, respectively) and black (non-Hispanic) adolescent females (ages 12 to 19; 45.5% and 26.6%, respectively). Among male youth, the highest overweight and obesity prevalence rates are found in MexicanAmerican boys (ages 6 to 11; 43.0% and 27.3%, respectively) and Mexican-American adolescent males (ages 12 to 19; 44.2% and 27.5%, respectively). Overweight prevalence rates for Native American children and adolescents (ages 5 to 17) were reported in a 1999 study to be 39.0% for males and 38.0% for females in the Aberdeen area Indian Health Service. Asian-American adolescents (ages 13 to 18) were reported to have an overweight prevalence of 20.6% in the 1996 National Longitudinal Study of Adolescent Health. Asian-American and Hispanic-American adolescents born in the United States from immigrant parents are more than twice as likely to be overweight as foreign-born adolescents who move to the United States.


14


TABLE 1.8 Overweight (85th Percentile) and Obesity (95th Percentile) Prevalence for Children and Adolescents by Racial Group Children (Ages 6 to 11) Prevalence (%) Race Black (non-Hispanic) Mexican American Caucasian (non-Hispanic)

Adolescents (Ages 12 to 19) Prevalence (%)

Overweight

Obesity

Overweight

Obesity

35.9 39.3 26.2

19.5 23.7 11.8

40.4 43.8 26.5

23.6 23.4 12.7

Source: Ogden, C.L. et al., JAMA, 288, 1728–1732, 2002. With permission.

AUSTRALIA

AND

CHINA

In Australia, between 1985 and 1995, the prevalence of obesity among children ages 7 to 15 years increased 4.6-fold among girls and 3.4-fold among boys [27]. Countries undergoing rapid urbanization and economic development are experiencing double challenges: They have to fight both childhood undernutrition and a growing tide of obesity [28–30]. For example, in China, the prevalence of overweight and obesity among children ages 7 to 9 years increased from 1% to 2% in 1985 to 17% among girls and 25% among boys in 2000 [30]. In addition, obesity prevalence varies across socioeconomic strata. In developed countries, children of low socioeconomic status are more affected than their wealthy counterparts [31–33]. The opposite is observed in developing countries, where children in the upper socioeconomic status are more likely than poor children to be obese [34,35].

HEALTH CONSEQUENCES OF OBESITY AND MORBIDITY Obesity has a great number of negative health, social, and economic consequences, as evidenced by the higher mortality and morbidity rates among overweight and obese individuals than lean people. Obese subjects have a 50 to 100% increased risk of premature death from all causes compared to individuals with a healthy weight. The health consequences of obesity range from a number of nonfatal complaints that impact the quality of life, such as respiratory difficulties, musculoskeletal disorders, skin problems, and infertility, to complaints that lead to an increased risk of premature death, including NIDDM, gallbladder disease, cardiovascular problems (hypertension, stroke, and coronary heart disease), and certain cancers. Hypertension, diabetes, and raised serum cholesterol are between two and six times more prevalent among heavier women. Severe obesity is associated with a 12-fold increase in mortality in 25 to 35 year olds when compared to lean individuals. The psychological consequences of obesity can range from lowered self-esteem to clinical depression; the rates of anxiety and depression are three to four times higher among obese individuals [3]. In addition to its physical consequences, obesity creates a massive social burden in that negative attitudes toward the obese can lead to discrimination in many areas of their lives, including health care and employment [3].

BENEFITS OF WEIGHT LOSS Modest weight reduction can significantly reduce the risk of these serious health conditions. Weight loss in overweight and obese individuals improves physical, metabolic, and endocrinological complications, often dramatically. Weight loss in obese persons can also improve depression, anxiety, psychosocial functioning, mood, and quality of life. In a 12-year study in the United States,



15

TABLE 1.9 Benefits of Weight Loss Obesity Comorbidity

Weight Loss

Benefits of Weight Loss

Mortality

10 kg

Diabetes

10 kg

>20% reduction in total mortality >30% reduction in diabetes-related death Reduction in obesity-related cancer death 50% reduction in fasting glucose

Blood pressure

10 kg

Blood lipids

10 kg

Blood clotting indices

—

Physical complication

5–10 kg

Ovarian function

>5%

10-mmHg reduction in systolic pressure 20-mmHg reduction in diastolic pressure 10% reduction in TOT cholesterol 15% reduction in LDL cholesterol 30% reduction in triglycerides 8% increase in HDL cholesterol Reduced red cell aggregability Improved fibrinolytic capacity Improved back and joint pain Improved lung function Decreased breathlessness Reduced frequency of sleep apnea Improved ovarian function

Source: WHO, Obesity: Preventing and Managing the Global Epidemic, Report of WHO Consultation on Obesity, World Health Organization, Geneva, 1998.

intentional weight loss of 0.5 to 9.0 kg in overweight women with existing obesity-related disease led to a 20% reduction in total mortality, a 40 to 50% reduction in mortality from obesity-related cancers, and a 30 to 40% reduction in diabetes-related deaths [3]. Table 1.9 shows the major benefits of weight loss on health status.

ECONOMIC COSTS OF OBESITY Often overshadowed by the health and social consequences of obesity is the economic cost to society and to the individual. The direct costs of diagnosis, treatment, and management of obesity within national healthcare systems have been assessed in only a few countries to date. Although the methodology varied considerably between studies, making it difficult to compare costs across countries and to extrapolate the results from one country to another, these estimates suggest that between 2 and 8% of the total healthcare costs in Western countries can be attributed to obesity [3]. This represents a major fraction of national healthcare budgets comparable with, for example, the total cost of cancer therapy. The potential impact on healthcare resources in the less-developed healthcare systems of developing countries is likely to be even more severe. In addition to the direct costs of obesity are costs in terms of the individual (including the intangible costs of poor health and reduced quality of life) and society (such as the indirect costs of loss of productivity due to sick-leave and premature pensions). Being able to determine the indirect costs of obesity that arise from, for example, the loss of wages and productivity would raise the total cost of obesity even higher. The IOTF is planning to investigate further the direct and indirect costs of obesity worldwide as part of its implementation plan. Data collected by the IOTF in 2002 are summarized in Table 1.10 [36]. Prevention is clearly more cost effective than treatment, both in terms of economic and personal costs.


16


TABLE 1.10 Examples of Direct Costs in European Union Compared with the United States Country England (1995) France (1992) Germany (1996) Portugal (1996) The Netherlands (1981–1989) United States

Direct Costs in Euros (millions)

Percent of Health Expenditure (%)

816 (+3270 indirect) 640–1320 10,600 230 454

1.5 1.5 — 3.5 4.0

US$70,000

7.0

Note: Data not adjusted for inflation. Source: IOTF and EASO, Obesity in Europe: The Case for Action, International Obesity Task Force and European Association for the Study of Obesity, London, 2002 (http://www.iotf.org/media/euobesity.pdf).

THE NEED FOR ACTION Obesity is a serious medical condition that requires urgent attention throughout the world. Despite its high prevalence and our improved understanding of how the disease develops, only limited effective obesity management systems are in place in national healthcare services around the world. This is in contrast with other chronic diseases, such as diabetes and coronary heart disease, where integrated care is frequently provided. It is clear, therefore, that the rational development of coordinated healthcare services for the management of overweight and obese patients is needed in most countries. Primary healthcare services should play the dominant role, although hospital and specialist services are also required for dealing with more severe cases and the associated major life-threatening complications. There is an urgent need for expanded training of all healthcare workers to improve their levels of knowledge and skills with regard to obesity management strategies. The IOTF was established in May 1996 to tackle the emerging global epidemic of obesity. The IOTF is a part of the International Association for the Study of Obesity (IASO), an organization that represents 43 national obesity associations across the globe. The IOTF is composed of world experts in the field of obesity and related diseases from around world, including China, Japan, Chile, Australia, Brazil, the United States, Canada, and Europe. The IOTF collaborates closely with the WHO and is engaged with other international health organizations and national governments to raise awareness and help develop solutions to the global epidemic of obesity. The IOTF aims to achieve taking action on the prevention and management of overweight and obesity and endeavors to create an environment that encourages and supports the development of appropriate public and health polices and programs for the prevention and management of obesity. The IOTF initiative on the prevention and management of obesity has four main goals: 1. Increase the awareness among governments, healthcare professionals, and the community that obesity is a serious medical condition and a major health problem with substantial economic costs. 2. Provide evidence and guidance for the development of better prevention and management strategies. 3. Secure the commitment of policymakers to take action. 4. Foster development of national, regional, and international structures that will enable and support the implementation of taking action on the problems of overweight and obesity. Management strategies are shown in Figure 1.6.



17

A systematic approach to management based on BMI and other risk factors Assess overall health risk from BMI and other risk factors (e.g., waist circumference) BMI

OVERALL HEALTH RISK Additional risk factors? NO

BMI 18.5– 24.9

MANAGEMENT STRATEGIES

YES

Healthy diet and advice on preventing weight gain.

Average

Increased

Elevated waist circumference: institute weight management. Family history of obesity: prevent weight gain >3 kg. Smoking: stop with dietary advice. Lipids high: dietary advice. Hypertensive: diet, exercise, weight maintenance. Glucose intolerance: exercise, diet, weight maintenance. Weight maintenance, healthy diet, exercise.

BMI Increased 25–29.9 Moderate

BMI Moderate 30–34.9

Goal of 5–10% weight loss without risk appropriate. Severe

BMI 35–39.9

Severe

BMI ≥40

Very severe

Goal for diet, exercise, behavior: primarily geared to risk management. Weight loss needed if risk not reduced substantially within 3 months, then aim for 5–10 kg over 24 weeks by mild energy deficit. If not achieving this weight reduction at 24 weeks and risks persist, test usefulness of drug to reduce risk by weight management.

Consider very low calorie diet and drug therapy if diet, exercise, and lifestyle program is unsuccessful after 12 weeks in reducing all risk factors. Useful therapy including drugs to achieve >10% weight loss.

Very severe

Refer to specialist for separate management and consideration of surgery if conventional treatment fails. Aim for 20–30% weight reduction.

FIGURE 1.6 A systematic approach to management based on BMI and other risk factors. (From WHO, Obesity: Preventing and Managing the Global Epidemic, Report of WHO Consultation on Obesity, World Health Organization, Geneva, 1998.)

In 1997, the WHO, together with the IOTF, held an expert consultation on obesity to review the extent of the obesity problem and examine the need to develop public health policies and programs to tackle the global problem of obesity. The consultation resulted in the publication of the interim report Obesity: Preventing and Managing the Global Epidemic [3] and the subsequent WHO Technical Report Series 894. The IOTF has identified a number of areas where our understanding of overweight and obesity must be improved. Specific working groups have examined the following issues: childhood obesity, economic costs of obesity, management of obesity, public health approaches to the prevention of obesity, and, finally, the training of health professionals.

REFERENCES [1]

WHO, Obesity: Preventing and Managing the Global Epidemic, Report of WHO Consultation on Obesity, Technical Report Series No. 894, World Health Organization, Geneva, Switzerland, 2000, p. 256. [2] Must, A. et al., The disease burden associated with overweight and obesity, JAMA, 282, 1523–1529, 1999. [3] WHO, Obesity: Preventing and Managing the Global Epidemic, Report of WHO Consultation on Obesity, World Health Organization, Geneva, 1998. [4] FAO, The Developing World’s New Burden: Obesity, Food and Agriculture Organization, United Nations, Geneva, Switzerland, 2002, http://www.fao.org/FOCUS/E/obesity/obes2.htm.


18

Obesity: Epidemiology, Pathophysiology, and Prevention [5] [6] [7] [8]

[9]

[10] [11]

[12]

[13]

[14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27]

[28] [29]

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[30] Wang, L. et al., Preventing chronic diseases in China, Lancet, 366, 1821–1824, 2005. [31] Stamatakis, E. et al., Overweight and obesity trends from 1974 to 2003 in English children: what is the role of socioeconomic factors?, Arch. Dis. Child., 90(10), 999–1004, 2005. [32] Strauss, R.S. and Pollack, H.A., Epidemic increase in childhood overweight, 1986–1998, JAMA, 286(22), 2845–2848, 2001. [33] Strauss, R.S., Childhood obesity, Pediatr. Clin. North Am., 49(1), 175–201, 2002. [34] Salmon, J. et al., Trends in children’s physical activity and weight status in high and low socioeconomic status areas of Melbourne, Victoria, 1985–2001, Aust. N.Z. J. Public Health, 29(4), 337–342, 2005. [35] Chhatwal, J., Verma, M., and Riar, S.K., Obesity among pre-adolescents and adolescents of a developing country (India), Asia Pac. J. Clin. Nutr., 13(3), 231–235, 2004. [36] IOTF/EASO, Obesity in Europe: The Case for Action, International Obesity Task Force and European Association for the Study of Obesity, London, 2002, http://www.iotf.org/media/euobesity.pdf.


3802_C002.fm Page 21 Monday, January 29, 2007 1:14 PM

of Obesity: 2 Epidemiology A Global Burden for the New Millennium Gopal C. Pain CONTENTS Introduction ......................................................................................................................................21 Body Mass Index .............................................................................................................................21 Significance of Waist Circumference and Waist-to-Hip Ratio........................................................22 Prevalence of Obesity ......................................................................................................................22 Childhood Obesity ...........................................................................................................................25 Obesity and Morbidity .....................................................................................................................25 Obesity and Mortality ......................................................................................................................25 Age and Sex .....................................................................................................................................27 Roles of Physical Inactivity and Eating Habits...............................................................................27 Conclusion........................................................................................................................................27 References ........................................................................................................................................28

INTRODUCTION Of the 1 billion overweight adults in the world, 300 million are clinically obese. This is an alarming situation, even in light of the limited availability of population-based data. Even in Asian and African countries experiencing acute starvation and underweight, obesity is still a problem. Obesity and overweight are major risk factors for chronic diseases, including type 2 diabetes, coronary heart disease, hypertension, stroke, and certain forms of cancer. An attempt has been made to review the epidemiology of obesity. Obesity in general occurs from excess fat deposition and insufficient energy expenditure. Body weight is usually measurable, and this approach is the one primarily used in clinical practice. Ideal or desirable body weights have been developed by the Metropolitan Insurance Company using weights associated with the lowest mortality so as to achieve maximum life span. The tables that were prepared indicated that the average weight for height at age 30 was ideal in terms of mortality [1]. In clinical practice, overweight is described as weighing 10% more than the desirable weight.

BODY MASS INDEX Though not a direct measure of obesity, the widely accepted means of assessing obesity is the body mass index (BMI). A very good correlation has been found between BMI and the percentage of body fat in a population. Table 2.1 provides the World Health Organization (WHO) classification of adults according to the BMI: BMI =

kg Body weight in kg = m2 (Height in m)2 21


22


TABLE 2.1 WHO Classification of Adults According to BMI Classification Underweight Normal range Overweight Preobese Obese class I Obese class II Obese class III

BMI

Risk of Comorbidities

40.00

Increased Moderate Severe Very severe

The BMI fails to distinguish general body obesity from abdominal obesity. The latter is more serious and is related to osteoarthritis; breast, colon, and prostate cancers; decreased glucose tolerance; and elevated low-density lipoprotein (LDL) cholesterol and triglycerides (together with smoking and high blood pressure). In an analysis carried out by the World Health Report 2002, approximately 58% of diabetes, 21% of ischemic heart disease, and 4 to 42% of certain cancers globally were attributable to BMIs above 21 kg/m2 [2]. The BMI does not distinguish between weight associated with muscles and weight associated with fat; therefore, the BMI may not correspond to the same degree of fatness across a population.

SIGNIFICANCE OF WAIST CIRCUMFERENCE AND WAIST-TO-HIP RATIO A waist-to-hip ratio greater than 1.0 in men and 0.85 in women indicates abdominal fat accumulation [3], but waist circumference alone provides a good indication of abdominal fat distribution that is associated with ill health [4,5]. Table 2.2 shows the correlations among sex-specific waist circumference, obesity, and the risk of metabolic dysfunctions and complications. A strong association exists between upper body (android) obesity and the development of type 2 diabetes mellitus [6]. Accumulation of abdominal fat is an important risk factor indicator, and in this respect waist circumference has an advantage over the BMI [7]. Table 2.3 highlights the relationship between waist measurement and the odds ratio for risk factors.

PREVALENCE OF OBESITY The prevalence of obesity is increasing worldwide at an alarming rate and is now a problem for both developed and developing countries. Even India, where a third of the population falls below the poverty line, has experienced steady growth in its relatively affluent urban middle class population to 200 million, of which 40 to 50 million are overweight [8]. Starvation and malnutrition

TABLE 2.2 Sex-Specific Waist Circumference and Risk of Metabolic Complications Associated with Obesity Waist Circumference (cm) Risk of Metabolic Complications Increased Substantially increased

Men

Women

>94 (≈37 in.) >102 (≈40 in.)

>80 (≈32 in.) >88 (≈35 in.)


Epidemiology of Obesity: A Global Burden for the New Millennium

23

TABLE 2.3 Relationship Between Waist Measurement and Odds Ratio for Risk Factors Men

Waist measurement (cm) Odds ratio for risk factors

Women

At Risk

High Risk

At Risk

High Risk

94–102 2.2 (1.8–2.8)

>102 4.6 (3.5–6.0)

80–88 0.6 (1.3–2.1)

>88 2.6 (2.0–3.2)

Risk factors: >6.5 mmol/L total cholesterol; 160 systolic or >95 mmHg diastolic blood pressure.

TABLE 2.4 Obesity Prevalence in Some African Countries and Populations

Country or Population Mauritius Cape Peninsula, South Africa (blacks) United Republic of Tanzania

Prevalence of Obesity (%)

Year

Age Group

Men

1992 1990 1986–1989

25–74 15–64 35–64

5 8 0.6

Women

Ref.

15 44 3.6

Hodge et al. [11] Steyn et al. [10] Berrios et al. [12]

TABLE 2.5 Obesity Prevalence in Selected European Countries Prevalence of Obesity (%)

Country

Year

Age Group

Men

Women

Ref.

England

1995

16–64

15

16.5

1991–1993 1992 1995

20–75 25–65 20–29

14 20.5 8.4

11 26.8 8.3

Prescott-Clarke and Primatesta [13] Seidell and Rissanen [14] Hoffmeister et al. [15] Seidell [16]

Finland Former Federal Republic of Germany Netherlands

coexist with obesity in many developing countries. In spite of the limited availability of populationbased data and differing definitions of obesity and age standardization, WHO has provided a clear global picture of the increased prevalence of obesity [9]. Table 2.4, Table 2.5, Table 2.6, Table 2.7, Table 2.8, and Table 2.9 provide data on the prevalence of obesity (BMI ≥ 30) in various countries as suggested by WHO. Table 2.8 provides insight into the prevalence of overweight (BMI ≥ 25), obese, and severely obese (BMI ≥ 40) persons in the United States, and Table 2.9 shows the overall global obesity prevalence in WHO regions. The most comprehensive data on obesity in Europe are those of the WHO MONICA study [17]. It has been observed that over the last 10 years the prevalence of obesity has increased by 10 to 40% in European countries. According to the Centers for Disease Control and Prevention (CDC), over half of the U.S. population is overweight (approximately 127 million), nearly one third is obese (60 million), and about 15 million are severely obese. Emerging evidence suggests that overweight and obesity have reached epidemic proportions globally.


24


TABLE 2.6 Obesity Prevalence in Selected Mediterranean Countries

Year

Age Group

Men

Women

Ref.

1994 1990–1993 1992

18+ 15+ 17+

32 16 16

41 24 38

Al-Isa [18] Al-Nuaim et al. [19] Musaiger [20]

Country Kuwait Saudi Arabia United Arab Emirates

Prevalence of Obesity (%)

TABLE 2.7 Obesity Prevalence in Selected Western Pacific Countries Prevalence of Obesity (%)

Country

Year

Age Group

Men

Women

Ref.

Australia China Japan New Zealand

1989 1992 1993 1989

25–64 20–45 20+ 18–64

11.5 1.20 1.7 10

13.2 1.64 2.7 13

Bennett and Magnus [21] WHO [pers. comm.] WHO [pers. comm.] Ball et al. [22]

TABLE 2.8 Overweight, Obese, and Severely Obese Prevalence in the United States Prevalence

Men Women Adolescents (ages 12–19) Children (ages 6–11) U.S. population

Overweight (BMI ≥ 25 kg/m2)

Obese (BMI ≥ 30 kg/m2)

Severely Obese (BMI ≥ 40 kg/m2)

67.0% 62.0% 30.4% 30.3% 127 million

27.7% 34.0% 15.5% 15.3% 60 million

3.1% 6.3% Not determined Not determined 15 million

Source: WHO, Controlling the Global Obesity Epidemic, World Health Organization, Geneva, 2003, www.who.int/nutrition/topics/obesity/en/.

TABLE 2.9 Obesity Prevalence in WHO Global Regions Obese Adults (BMI ≥ 30 kg/m2) WHO Region The Americas Europe Western Pacific Eastern Mediterranean Global population

Prevalence (%)

Number of People (Millions)

20.9 16.7 3.8 10.0 8.9

109.0 106.5 42.5 24.9 315.0

Source: Worldwide Obesity: Trends Global Obesity Trends, Globesity the Growing Epidemic of Chronic Overweight, 2006, http://www.annecollins.com/obesity/worldwide-obesity.htm.



25

Papua New Guinea Bangladesh Philippines Burkina Faso Singapore Togo Tunisia Rwanda India Indonesia Belize Jordan Tahiti Nicaragua Brazil Saint Lucia United Kingdom Yogoslavia Antigua Zambia Venezuela Italy Panama Peru Barbados Honduras Lesotho Bolivia Trinidad & Tobago Iran (Islamic Republic of) Mauritius Canada Jamaica Chile 0

2

4 6 8 Percentage of obese preschool children

10

FIGURE 2.1 Prevalence of obese preschool children (0 to 59 months) in selected countries and territories.

CHILDHOOD OBESITY So far, no agreement has been reached with regard to the classification of overweight and obesity in children and about a globally applicable reference population, yet an attempt has been made by WHO to compile data on the global prevalence of obesity in childhood [25]. Children were defined as obese when they exceeded the National Center for Health Statistics (NCHS) median weight for height plus two standard deviations or Z-scores. According to Martorell [26], the prevalence of obesity in the reference population was 2.3%. With the exception of Pakistan, where 2.6% of children were obese, obesity was rare in South Asia (including India) and in Thailand. Figure 2.1 clearly illustrates that the prevalence of obesity is high in most of the developing and developed parts of the world.

OBESITY AND MORBIDITY According to Jung [27], obesity results in a multiplicity of problems, and a weight loss of 10 kg can have beneficial health effects (see Table 2.10 and Table 2.11).

OBESITY AND MORTALITY A close relationship exists between obesity and mortality. In the Nurses’ Health Study, Manson et al. [28] demonstrated an almost linear and continuous relationship between BMI and premature


26


TABLE 2.10 Morbidity and Obesity Aspect Cardiovascular system

Respiratory system

Gastrointestinal system

Metabolic system

Neurology

Effect of Obesity Hypertension Coronary heart disease Cerebrovascular disease Varicose veins Deep venous thrombosis Hypertension

Aspect

Effect of Obesity

Breast

Breast cancer Male gynecomastia

Uterus

Endometrial cancer Cervical cancer

Urological

Breathlessness Sleep apnea Hypoventilation syndrome

Prostate cancer Stress incontinence

Skin

Hiatus hernia Gallstones and cholelithiasis Fatty liver and cirrhosis Hemorrhoids Hernia Cancer (colorectal)

Sweat rashes Fungal infections Lymphoedema Cellulitis Acanthosis nigracans

Orthopedic

Osteoarthritis Gout

Endocrine system

Reduced growth hormone and IGF1 Reduced prolactin response Hyperdynamic ACTH response to CRH Increased urinary free cortisol Altered sex hormones

Pregnancy

Obstetric complications Cesarean operation Large babies Neural tube defects

Hyperlipidemia Insulin resistance Diabetes mellitus Polycystic ovarian syndrome Hyperandrogenization Menstrual irregularities Nerve entrapment

TABLE 2.11 Benefits of a 10-kg Weight Loss Mortality

20–25% reduction in total mortality 30–40% reduction in diabetes-related deaths 40–50% reduction in obesity-related cancer deaths

Blood pressure

10-mmHg reduction in systolic pressure 20-mmHg reduction in diastolic pressure

Angina

Symptoms reduced by 91% 33% increase in exercise tolerance

Lipids

10% reduction in total cholesterol 15% reduction in LDL cholesterol 30% reduction in triglycerides 8% increase in HDL cholesterol

Diabetes

>50% reduction in risk of developing diabetes 30–50% reduction in fasting blood glucose 15% reduction in HbA1c

mortality (Figure 2.2). After removing confounding variables such as smoking and subclinical disease, it was found that the relative risk of premature mortality gradually increases with increasing BMI. After the analysis of numerous data, the American Institute of Nutrition concluded that the lowest mortality risk is associated with a BMI between 18 and 25 kg/m2 [29].



27

2.5 All women

Women who never smoked

2.0

Risk

Women who never smoked and recently had stable weight 1.5

1.0

0.5

Obesity: Epidemiology, Pathophysiology, and Prevention

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Ovarian Hyperstimulation Syndrome: Epidemiology, Pathophysiology, Prevention and Management

Obesity Prevention and Public Health

Childhood Obesity Prevention and Treatment, Second Edition

Epidemiology, Causes and Prevention of Skin Diseases

Hernia Infections: Pathophysiology - Diagnosis - Treatment - Prevention

Child and Adolescent Obesity: Causes and Consequences, Prevention and Management

Children, Obesity and Exercise: Prevention, Treatment and Management of Childhood and Adolescent Obesity

Epidemiology, Pathogenesis, and Prevention of Head and Neck Cancer

Global Perspectives on Childhood Obesity: Current Status, Consequences and Prevention

Childhood Obesity: Risk Factors, Health Effects and Prevention

Epidemiology: Key to Prevention (Statistics for Biology and Health)

Epidemiology and Prevention of Vaccine-Preventable Diseases (10th Edition)

Atopic Dermatitis: The Epidemiology, Causes and Prevention of Atopic Eczema

Obesity

Heart Physiology and Pathophysiology

Epidemiology of Obesity in Children and Adolescents: Prevalence and Etiology (Springer Series on Epidemiology and Public Health, Volume 2)

Nutrition Therapy and Pathophysiology

Handbook of Obesity Prevention: A Resource for Health Professionals

Handbook of obesity prevention. A resource for health professionals

Obesity: Genomics and Postgenomics

Heart Physiology and Pathophysiology

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