Molecular basis of human nutrition

Preface ix Acknowledgements x 1 Introduction 1 1.1 What is nutrition? 1 1.2 Estimation of nutrient requirements 3 Summary 11 Further reading 12 2 Energy 13 2.1 Energy content of foods 13 2.2 Sources of energy 15 2.3 Energy expenditure 16 2.4 Energy requirements 22 2.5 Energy balance 23 Summary 26 Further reading 26 3 Protein 27 3.1 The need for protein 27 3.2 Protein chemistry 28 3.3 Food sources 32 3.4 Digestion, absorption and metabolism 33 3.5 Classification of amino acids as essential or non-essential 37 3.6 Protein quality 38 3.7 Protein requirements and recommended intakes 41 Summary 43 Further reading 43 4 Carbohydrate 44 4.1 Introduction 44 4.2 Classification 45 4.3 Carbohydrate intake 51 4.4 Digestion and absorption 52 4.5 Metabolism of a glucose load 54 © 2003 Taylor & Francis C O N T E N T S vi 4.6 Effects of unavailable carbohydrate intake on health 55 Summary 57 Further reading 57 5 Fat 58 5.1 Introduction 58 5.2 The chemistry of fats 58 5.3 Composition of different dietary fats 64 5.4 The digestion of fat 64 5.5 Physiological role of fat 66 5.6 Relationship between the intake of polyunsaturated fatty acids and vitamin E intake 73 5.7 Dietary intakes of fat 74 5.8 Dietary Reference Values for fat and fatty acids 74 Summary 75 Further reading 75 6 Minerals 76 6.1 Sodium, potassium and chloride 76 6.2 Calcium, phosphorus, magnesium and fluoride 80 6.3 Iron, copper and zinc 84 6.4 Selenium, iodine and chromium 89 Summary 92 Further reading 93 7 Vitamins 94 7.1 Thiamin, niacin, riboflavin, biotin and pantothenic acid 95 7.2 Vitamin B12, folate and vitamin B6 101 7.3 Vitamin C 105 7.4 Fat-soluble vitamins A, D, K and E 106 Summary 114 Further reading 114 8 Deficiency and toxicity disorders 115 8.1 Introduction 115 8.2 Protein Energy Malnutrition 116 8.3 Vitamin A deficiency disease 119 8.4 Rickets and osteomalacia 120 8.5 Pellagra 122 8.6 Thiamin deficiency 122 8.7 Iodine deficiency disease 123 8.8 Nutritional anaemias 124 8.9 Toxicities 125 Summary 129 Further reading 129 9 Diet-related disease 130 9.1 Obesity 132 9.2 Type II diabetes 135 9.3 Cardiovascular disease 137 9.4 Diet and cancer 142 9.5 Dental caries 146 Summary 147 Further reading 148 10 Food 149 10.1 Idiosyncratic adverse reactions to food 149 10.2 Naturally occurring toxicants in food 150 © 2003 Taylor & Francis vii C O N T E N T S 10.3 Contaminants 153 10.4 Food additives 158 10.5 New developments 158 10.6 Genetically modified food 159 Summary 161 Final remarks and conclusion 161 Further reading