Treating and preventing obesity

Preface V Foreword VII List of Contributors XVI Treating and Preventing Obesity A Systematic Review of the Evidence 1 Summary 1 Background 1 Definition of Obesity 1 Causes of Obesity 2 Health Risks of Obesity 3 Impact on Quality of Life 3 Economic Aspects 3 Report Design and Content 3 Preventive Interventions against Obesity 4 Preventing Obesity in Adults 5 Preventing Obesity in Children and Adolescents 5 Treating Obesity 6 Treating Obesity in Adults 6 Treating Obesity in Children and Adolescents 10 Quality of Life 10 Effect of Weight Loss on Obesity-related Diseases and Conditions 11 Cost Effectiveness of Different Treatment Methods 11 Conclusions by SBU 12 1 Background 15 1.1 Obesity as a Health Problem in Adults 15 1.1.1 What is Obesity? 15 1.1.2 Prevalence of Obesity in Different Population Groups 17 1.1.3 Causes of Obesity 19 1.1.3.1 Energy Intake 20 1.1.3.2 Energy Utilization 21 Contents IX Treating and Preventing Obesity. Edited by J. Östman, M. Britton, E. Jonsson Copyright
2004 WILEY-VCH Verlag GmbH & Co. KgaA, Weinheim ISBN 3-527-30818-0 1.1.3.3 Risk Factors for Obesity 22 1.1.3.4 Genetic Factors 22 1.1.4 Risks of Obesity 23 1.1.4.1 Mortality 23 1.1.4.2 Cardiovascular Disease 25 1.1.4.3 Diabetes mellitus (type 2) 25 1.1.4.4 Cancer 26 1.1.4.5 Gall Bladder and Liver Diseases 26 1.1.4.6 Musculoskeletal Diseases 27 1.1.4.7 Production of Sex Hormones 27 1.1.4.8 Diseases of the Respiratory Organs 27 1.1.4.9 Health-related Quality of Life 27 1.1.5 Summary 28 1.1.6 Comments on Facts 1–4 28 1.2 Obesity as a Health Problem in Children and Adolescents 34 1.2.1 Background 34 1.2.2 Definition 34 1.2.3 Causes of Obesity 36 1.2.4 Morbidity and Obesity 37 1.2.5 Risk of Children becoming Overweight Adults 38 1.2.6 Summary 39 1.3 International Overview of Obesity Intervention Programs 42 1.3.1 Australia 42 1.3.2 France 43 1.3.3 Norway 43 1.3.4 New Zealand 44 1.3.5 Finland 45 1.3.6 Canada 45 1.3.7 Sweden 46 1.3.8 United States 46 1.4 Cost of Obesity and Obesity-Related Diseases 47 1.4.1 Methods of Estimating the Cost to Society 47 1.4.2 Methods of Searching the Literature 47 1.4.3 Results 48 1.4.3.1 Studies Addressing Direct Costs of Obesity 48 1.4.3.2 Studies Concerning Other Economic Aspects 50 1.4.3.3 Conclusions 53 2 Systematic Literature Review – Methods 57 2.1 Background 57 2.2 Literature Search 57 2.3 Literature Review and Quality Assessment 58 2.4 Reporting Facts and Conclusions 61 X Contents 3 Preventing Obesity 63 3.1 Preventing Obesity in Adults 63 Summary 63 3.1.1 Introduction 63 3.1.2 Methods 65 3.1.3 Results 66 3.1.4 Discussion 72 3.2 Preventing Obesity in Children and Adolescents 75 Summary 75 3.2.1 Methods 75 3.2.2 Results 76 3.2.3 Interesting Observations that do not Meet the Minimum Criteria 86 3.2.4 Discussion 89 4 Treating Obesity in Adults 93 4.1 Dietary Treatment 93 Summary 93 4.1.1 Introduction 94 4.1.2 Special Methodological Problems in Studies of Weight Loss 95 4.1.3 Methods 96 4.1.4 Results and Discussion 97 4.1.4.1 General Dietary Counseling, Different Types of Programs 97 4.1.4.2 Energy (Calorie) Restriction 109 4.1.4.3 Meal Replacement 111 4.1.4.4 Fat Restriction, with or without Energy Limitations 112 4.1.4.5 Carbohydrate Type 113 4.1.4.6 Lactovegetarian Diet 114 4.1.4.7 Commercial Weight-Loss Programs 114 4.1.4.8 Other Aspects 115 4.2 Special Diets 120 4.2.1 Dietary Fiber 120 Summary 120 4.2.1.1 Introduction 120 4.2.1.2 Methods 121 4.2.1.3 Results 121 4.2.1.4 Discussion 121 4.2.2 Low-Energy Diets 122 Summary 122 4.2.2.1 Introduction 123 4.2.2.2 Method 124 4.2.2.3 Results 125 4.2.3 Fasting 128 Summary 128 4.2.3.1 Introduction 128 4.2.3.2 Results 129 Contents XI 4.3 Behavior Therapy 131 Summary 131 4.3.1 Introduction 131 4.3.2 Methods 132 4.3.3 Results 132 4.3.4 Discussion 136 4.4 Physical Exercise 139 Summary 139 4.4.1 Introduction 139 4.4.2 Special Methodological Problems in Studies of Physical Exercise 139 4.4.3 Methods 140 4.4.4 Results 141 4.4.5 Discussion 144 4.5 Pharmacotherapy 149 Summary 149 4.5.1 Introduction 150 4.5.2 Methodological Aspects of Drug Studies 150 4.5.3 Orlistat and Sibutramine 151 4.5.4 Other Drugs 152 4.5.5 Method 152 4.5.6 Results 153 4.5.6.1 Orlistat 153 4.5.6.2 Sibutramine 158 4.5.6.3 Caffeine/Ephedrine 160 4.6 Surgery 162 Summary 162 4.6.1 Introduction 163 4.6.2 Literature Search 164 4.6.3 Findings on Weight Reduction and Complications 165 4.6.3.1 Gastric Bypass (GBP) 165 4.6.3.2 Horizontal Gastroplasty (HGPL) 167 4.6.3.3 Vertical Banded Gastroplasty (VBG) 168 4.6.3.4 Gastric Banding (GB) 176 4.6.3.5 Complications Following Stomach Procedures 178 4.6.3.6 Intestinal Bypass 178 4.6.3.7 Bileopancreatic Bypass (BPB) and Duodenal Switch (DS) 179 4.6.3.8 Laparoscopic or Open Surgery 180 4.6.4 Surgery Compared to Conservative Treatment and Effects on Risk Factors 181 4.6.5 The SOS Study 181 4.6.5.1 Aim and Design 181 4.6.5.2 Weight Loss in the SOS Study 182 4.6.5.3 Surgical Complications in the SOS Study 182 4.6.5.4 Effects on Risk Factors in the SOS Study 183 XII Contents 4.6.5.5 Effects on the Cardiovascular System in the SOS Study 183 4.6.5.6 Quality of Life in SOS Before and After Weight Loss 184 4.6.5.7 Health Economics and SOS 185 4.6.6 Appendix: Glossary and Surgical Details 185 4.6.6.1 Glossary 185 4.6.6.2 Description of Surgical Methods 190 4.6.6.3 Technical Considerations in Obesity Surgery 192 4.7 Alternative Medicine 201 Summary 201 4.7.1 Introduction 201 4.7.2 Definition of Alternative Medicine 202 4.7.3 Alternative Medicine Methods Used to Treat Obesity 202 4.7.4 Costs 204 4.7.5 Methods 204 4.7.6 Critical Review of Studies 205 4.7.7 Results 206 4.7.8 Studies Fulfilling the Minimum Criteria 206 4.7.8.1 Acupuncture 207 4.7.8.2 Hypnosis 209 4.7.8.3 Other Studies 212 4.7.8.4 Discussion and Conclusions 214 4.7.9 Overview of Recent Chinese Studies 216 4.7.9.1 Literature Search 216 4.7.9.2 Results 216 4.7.9.3 Discussion and Conclusions 217 4.8 Negative Effects of Weight Loss 220 4.9 Maintaining Weight Loss 223 5 Treating Obesity in Children and Adolescents 227 Summary 227 5.1 Dietary Intervention, Exercise, and Behavior Modification/Family Therapy 228 5.1.1 Results 228 5.2 Long-Term Effects of Different Treatments 238 5.2.1 Observations that do not Meet the Minimum Criteria 239 5.2.3 Pharmacotherapy 242 5.2.4 Surgery 242 5.2.5 Very Low Calorie Diet (VLCD) 247 5.2.6 Other Types of Treatment 250 5.2.6.1 Residential 250 5.2.6.2 Weight Watcher Treatment in Children 250 5.2.6.3 Physical Exercise 250 5.2.6.4 Alternative Medicine 251 5.3 Effects of Treatment on Risk Factors and Mental Health 251 5.4 Side Effects of Treatment 252 Contents XIII 5.5 Discussion 254 5.5.1 Behavior Modification, Diet, and Exercise 255 5.5.2 Surgical Intervention 256 5.5.3 VLCD 256 6 Quality of Life 261 Summary 261 6.1 Introduction 262 6.2 Methods 263 6.3 Results 263 6.3.1 Quality of Life in Overweight and Obese People 263 6.3.2 Studies of Obese People who Seek Treatment 267 6.3.3 Comparisons with People having other Chronic Disease and Disability 268 6.3.4 Specific Psychosocial Problems in Obese Patients 271 6.3.5 Effects of Surgery on Quality of Life 272 6.3.6 Effects of Non-Surgical Treatment on Quality of Life 274 6.4 Appendix: Conclusions and Need for Research 276 6.4.1 Quality of Life and Obesity: Population Studies 276 6.4.2 Quality of Life and Obesity: Clinical Studies 276 6.4.3 Quality of Life after Surgery for Severe Obesity 276 6.4.4 Quality of Life after Nonsurgical Treatment for Obesity 277 6.4.5 Need for Further Research 277 7 Effects of Obesity Treatment on Diseases and Special Conditions 281 7.1 Diabetes Mellitus (Type 2) 281 Summary 281 7.1.1 Introduction 282 7.1.2 Methods 282 7.1.3 Results 282 7.1.3.1 Effects of Obesity Treatment on Type 2 Diabetes 282 7.1.3.2 Prevention of Type 2 Diabetes 288 7.1.4 Discussion 292 7.2 Hypertension 297 Summary 297 7.2.1 Introduction 297 7.2.2 Results 297 7.2.2.1 Effect of Obesity Treatment on Hypertension 297 7.2.2.2 Prevention of Hypertension 301 7.2.3 Discussion 302 7.3 Blood Lipid Disorders 306 Summary 306 7.3.1 Background 306 7.3.2 Method 307 XIV Contents 7.3.3 Results 307 7.3.3.1 Diet Treatment Including VLCD 307 7.3.3.2 Pharmacotherapy 312 7.3.3.3 Surgical Treatment 313 7.3.3.4 Other Studies on Lowering Blood Lipids 313 7.3.4 Discussion 314 7.4 Sleep Apnea 317 Summary and Conclusion 317 7.4.1 Introduction 317 7.4.2 Method 317 7.4.3 Results 317 7.5 Infertility and Pregnancy Outcome 320 Summary and Conclusions 320 7.5.1 Introduction 320 7.5.2 Results 320 8 Economic Evaluation of Treatment Methods 323 Summary 323 8.1 Method 324 8.2 Results 324 8.2.1 Counseling and VLCD 324 8.2.2 Surgical intervention 328 8.2.3 Pharmacotherapy 332 9 Ethical Aspects 335 9.1 Patients’ Problems 336 9.2 Treatment 336 9.3 Interaction with Health Services 337 9.4 Quackery 338 9.5 Obesity as a Social Problem 338 9.6 General Prevention 339 Glossary and Definitions 341 Index 349 Contents