The Evolutionary Biology of Human Body Fatness: Thrift and Control (Cambridge Studies in Biological and Evolutionary Anthropology, Series Number 58)

This Comprehensive Synthesis Of Current Medical And Evolutionary Literature Addresses Key Questions About The Role Body Fat Plays In Human Biology. It Explores How Body Energy Stores Are Regulated, How They Develop Over The Life-course, What Biological Functions They Serve, And How They May Have Evolved. There Is Now Substantial Evidence That Human Adiposity Is Not Merely A Buffer Against The Threat Of Starvation, But Is Also A Resource For Meeting The Energy Costs Of Growth, Reproduction And Immune Function. As Such It May Be Considered As Important In Our Species Evolution As Other Traits Such As Bipedalism, Large Brains, And Long Life Spans And Developmental Periods. Indeed, Adiposity Is Integrally Linked With These Other Traits, And With Our Capacity To Colonise And Inhabit Diverse Ecosystems. It Is Because Human Metabolism Is So Sensitive To Environmental Cues That Manipulative Economic Forces Are Now Generating The Current Obesity Epidemic--provided By Publisher. Machine Generated Contents Note: 1. Introduction; 2. Human Fatness In Broad Context; 3. The Proximate Causes Of Fat Deposition; 4. The Ontogenetic Development Of Adiposity; 5. The Life-course Induction Of Adiposity; 6. The Fitness Value Of Fat; 7. The Evolutionary Biology Of Adipose Tissue; 8. Adiposity In Hominid Evolution; 9. Adiposity In Human Evolution; 10. The Evolution Of Obesity. Jonathan C.k. Wells. Includes Bibliographical References And Index. Half-title......Page 3 Series-title......Page 4 Title......Page 5 Copyright......Page 6 Dedication......Page 7 Contents......Page 9 Preface......Page 11 1 Introduction......Page 15 2 Human fatness in broad context......Page 30 2.1 Body composition techniques......Page 31 2.2 Cross-species comparisons......Page 34 2.3 Comparisons within humans: Body mass index......Page 39 2.4 The limitations of percentage fat......Page 43 2.5 Between-populations comparisons based on skinfolds......Page 50 2.6 Sexual dimorphism......Page 51 2.7 Population variability in shape......Page 57 Summary......Page 61 3.1 The energy balance equation......Page 63 Heritability......Page 69 Body fatness as a polygenic trait......Page 72 Imprinted genes......Page 73 Epigenetic effects......Page 74 Extra-somatic contributions......Page 75 3.3 Neurobiology of appetite......Page 76 3.4 Endocrine and paracrine factors......Page 78 Insulin and other pancreatic hormones......Page 79 Cortisol......Page 81 Leptin......Page 82 Sex hormones......Page 83 Paracrine regulation......Page 84 3.5 Inflammation......Page 86 3.6 Dietary composition......Page 87 3.7 Physical activity level......Page 91 3.8 Eating style......Page 96 3.9 Parenting behaviour......Page 97 3.10 Psychological stress......Page 101 3.11 Fat deposition in a toxic environment......Page 102 Summary......Page 105 4 The ontogenetic development of adiposity......Page 106 4.1 Fetal life......Page 107 4.2 Body composition at birth......Page 109 4.3 Body composition during infancy......Page 113 4.4 Body composition during childhood and adolescence......Page 117 4.5 Adulthood......Page 122 4.6 Pregnancy......Page 127 4.7 Lactation......Page 129 Summary......Page 130 5 The life-course induction of adiposity......Page 132 5.1 Phenotypic induction and tracking......Page 133 5.2 The limitation of outcomes......Page 137 5.3 Induction of body size......Page 140 5.4 Induction of neonatal body composition during fetal life......Page 141 5.5 Induction of later body composition by fetal experience......Page 145 5.6 Induction of body composition by post-natal growth......Page 151 5.7 Induction of body composition during childhood......Page 156 5.9 Induction of the rate of maturation......Page 162 Summary......Page 165 6.1 Buffering famine and malnutrition......Page 167 6.2 Accommodating fluctuations in energy supply......Page 175 Summary......Page 182 6.4 Adaptation to cold......Page 183 Conception......Page 186 Pregnancy......Page 189 Lactation......Page 190 Summary......Page 192 6.6 Regulation of offspring growth......Page 193 6.7 Buffering of the offspring brain......Page 194 6.8 Immune function......Page 197 6.9 Sexual selection......Page 201 Summary......Page 207 7.1 Evolution of the adipocyte and adipose tissue......Page 209 7.2 Fat stores as adaptive strategy......Page 212 7.3 Adipose tissue in mammalian evolution......Page 213 7.4 The thrifty-genotype hypothesis......Page 217 7.5 The thrifty-phenotype hypothesis......Page 218 7.6 Integrating two models of thrift......Page 222 7.7 A game-theory model of fat stores......Page 223 7.8 Summary......Page 227 8 Adiposity in hominin evolution......Page 229 8.1 Trends in seasonality......Page 230 8.2 Trends in body size......Page 233 8.3 Trends in encephalisation......Page 239 8.4 Trends in growth patterns......Page 245 8.5 Trends in diet, metabolism and appetite......Page 246 8.6 The evolution of a colonising reproductive strategy......Page 249 8.7 Trends in disease load......Page 252 8.8 Trends in social stress......Page 254 Summary......Page 256 9 Adiposity in human evolution......Page 258 9.1 Genetic diversification and physical environments......Page 259 9.2 Genetic diversification through niche construction......Page 261 9.3 The origins of farming and famines......Page 263 9.4 The emergence of social stratification......Page 267 9.5 Re-evaluating the thrifty-genotype hypothesis......Page 270 9.6 Variable disease load......Page 274 9.7 Genetic variability and bet-hedging......Page 278 9.8 The thrifty-phenotype hypothesis and population-metabolic variability......Page 279 Summary......Page 282 10 The evolution of human obesity......Page 284 10.1 The evolutionary history of obesity......Page 285 10.2 The creation of the obesogenic niche......Page 289 10.3 Secular trends in diet......Page 290 10.4 Secular trends in physical activity......Page 294 10.5 Changes in circadian rhythms......Page 298 10.6 Secular trends in social stress......Page 299 10.7 Secular trends in reproductive behaviour......Page 301 10.8 Secular trends in exposure to pharmacological agents, toxins and disease......Page 303 10.9 The global obesity epidemic......Page 304 10.10 Obesity and capitalism......Page 306 10.11 The future of obesity......Page 312 References......Page 316 Index......Page 377 Half-title 3 Series-title 4 Title 5 Copyright 6 Dedication 7 Contents 9 Preface 11 1 Introduction 15 2 Human fatness in broad context 30 2.1 Body composition techniques 31 2.2 Cross-species comparisons 34 2.3 Comparisons within humans: Body mass index 39 2.4 The limitations of percentage fat 43 2.5 Between-populations comparisons based on skinfolds 50 2.6 Sexual dimorphism 51 2.7 Population variability in shape 57 Summary 61 3 Proximate causes of lipid deposition and oxidation 63 3.1 The energy balance equation 63 3.2 Genetic factors 69 Heritability 69 Body fatness as a polygenic trait 72 Imprinted genes 73 Epigenetic effects 74 Extra-somatic contributions 75 Summary 76 3.3 Neurobiology of appetite 76 3.4 Endocrine and paracrine factors 78 Endocrine regulation 79 Insulin and other pancreatic hormones 79 Cortisol 81 Leptin 82 Sex hormones 83 Cytokines 84 Paracrine regulation 84 Summary 86 3.5 Inflammation 86 3.6 Dietary composition 87 3.7 Physical activity level 91 3.8 Eating style 96 3.9 Parenting behaviour 97 3.10 Psychological stress 101 3.11 Fat deposition in a toxic environment 102 Summary 105 4 The ontogenetic development of adiposity 106 4.1 Fetal life 107 4.2 Body composition at birth 109 4.3 Body composition during infancy 113 4.4 Body composition during childhood and adolescence 117 4.5 Adulthood 122 4.6 Pregnancy 127 4.7 Lactation 129 Summary 130 5 The life-course induction of adiposity 132 5.1 Phenotypic induction and tracking 133 5.2 The limitation of outcomes 137 5.3 Induction of body size 140 5.4 Induction of neonatal body composition during fetal life 141 5.5 Induction of later body composition by fetal experience 145 5.6 Induction of body composition by post-natal growth 151 5.7 Induction of body composition during childhood 156 5.8 Mechanisms of body composition induction 162 5.9 Induction of the rate of maturation 162 5.10 Transgenerational effects 165 Summary 165 6 The fitness value of fat 167 6.1 Buffering famine and malnutrition 167 Summary 175 6.2 Accommodating fluctuations in energy supply 175 Summary 182 6.3 Mechanical Functions 183 6.4 Adaptation to cold 183 Summary 186 6.5 Regulation of reproduction 186 Conception 186 Pregnancy 189 Lactation 190 Summary 192 6.6 Regulation of offspring growth 193 6.7 Buffering of the offspring brain 194 6.8 Immune function 197 Summary 201 6.9 Sexual selection 201 Summary 207 Summary 207 7 The evolutionary biology of adipose tissue 209 7.1 Evolution of the adipocyte and adipose tissue 209 7.2 Fat stores as adaptive strategy 212 7.3 Adipose tissue in mammalian evolution 213 7.4 The thrifty-genotype hypothesis 217 7.5 The thrifty-phenotype hypothesis 218 7.6 Integrating two models of thrift 222 7.7 A game-theory model of fat stores 223 7.8 Summary 227 8 Adiposity in hominin evolution 229 8.1 Trends in seasonality 230 8.2 Trends in body size 233 8.3 Trends in encephalisation 239 8.4 Trends in growth patterns 245 8.5 Trends in diet, metabolism and appetite 246 8.6 The evolution of a colonising reproductive strategy 249 8.7 Trends in disease load 252 8.8 Trends in social stress 254 Summary 256 9 Adiposity in human evolution 258 9.1 Genetic diversification and physical environments 259 9.2 Genetic diversification through niche construction 261 9.3 The origins of farming and famines 263 9.4 The emergence of social stratification 267 9.5 Re-evaluating the thrifty-genotype hypothesis 270 9.6 Variable disease load 274 9.7 Genetic variability and bet-hedging 278 9.8 The thrifty-phenotype hypothesis and population-metabolic variability 279 Summary 282 10 The evolution of human obesity 284 10.1 The evolutionary history of obesity 285 10.2 The creation of the obesogenic niche 289 10.3 Secular trends in diet 290 10.4 Secular trends in physical activity 294 10.5 Changes in circadian rhythms 298 10.6 Secular trends in social stress 299 10.7 Secular trends in reproductive behaviour 301 10.8 Secular trends in exposure to pharmacological agents, toxins and disease 303 10.9 The global obesity epidemic 304 10.10 Obesity and capitalism 306 10.11 The future of obesity 312 References 316 Index 377 0521884209,9780521884204