Nutrition : Maintaining and improving health, Fourth edition

625 Pages·2012·6.08 MB·English

by  Press

Nutrition
Maintaining and improving health
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Nutrition
Maintaining and improving health
Fourth edition
Geoffrey P Webb BSc MSc PhD
Nutrition writer, and consultant at the School of Health,
Sport and Bioscience, University of East London, London, UK
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CRC Press
Taylor & Francis Group
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Version Date: 20150220
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For my daughter Kate Webb on the understanding
that she dedicates her first book to me.
Accessing the resources on the companion website
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Contents
Preface xi
Acknowledgements xiv
PART 1 – CONCEPTS AND PRINCIPLES
1. Changing priorities for nutrition education 3
Identification of the essential nutrients 3
Adequacy: the traditional priority in nutrition 5
The current priority: diet as a means to health promotion or disease prevention 7
Is intervention to induce dietary change justified? 16
Effecting dietary change 23
Concluding remarks 29
2. Food selection 30
Introduction and aims of the chapter 30
The biological model of food 31
Dietary and cultural prejudice 32
Food classification systems 33
Non-nutritional uses of food 38
The hierarchy of human needs 39
A model of food selection: the ‘hierarchy of availabilities’ model 41
Physical availability 42
Economic availability 43
Cultural availability 56
‘Gatekeeper’ limitations on availability 62
3. Methods of nutritional assessment and surveillance 64
Introduction and aims of the chapter 64
Strategies for nutritional assessment 64
Measurement of food intake 65
Tables of food composition 72
Dietary standards and nutrient requirements 75
Clinical signs for the assessment of nutritional status 85
Anthropometric assessment in adults 86
Anthropometric assessment in children 92
Estimating fatness in animals 94
Biochemical assessment of nutritional status 95
Measurement of energy expenditure and metabolic rate 98
4. Methods to establish links between diet and chronic disease 102
Introduction and aims of the chapter 102
Strategic approaches: observational versus experimental 102
Features and problems of epidemiological methods 104
Cross-cultural comparisons 107
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Contents vii
Time trends 110
Migration studies 112
Cohort studies 112
Case–control studies 115
Cross-sectional studies 117
‘Experiments’ of nature 118
Animal experiments 118
Human experimental studies 121
In-vitro studies 132
Scientific honesty 133
5. Dietary guidelines and recommendations 134
The range of ‘expert reports’ and their consistency 134
Variations in the presentation of guidelines and recommendations 136
‘Food’ recommendations 137
Energy and body weight 139
Recommendations for fats, carbohydrates, protein and salt 140
Alcohol 143
How current UK diets compare with ‘ideal’ intakes 146
Other nutrients 147
Willingness to change 147
Some barriers to dietary change 149
Aids to food selection 150
Concluding remarks 154
6. Cellular energetics 156
Introduction and aims of the chapter 156
Overview of metabolism 156
Metabolism of glucose and the monosaccharides 158
Metabolism of fatty acids and glycerol 160
Metabolism of amino acids 161
The pentose phosphate pathway 161
Overview of macronutrient handling in the gut 162
PART 2 – ENERGY, ENERGY BALANCE AND OBESITY
7. Introduction to energy aspects of nutrition 167
Sources of energy 167
Units of energy 167
How energy requirements are estimated 168
Variation in average energy requirements: general trends 170
Energy content of foods 171
Sources of dietary energy by nutrient 172
Energy density 174
Nutrient density 176
Sources of dietary energy by food groups 177
Starvation 178
Eating disorders 182
Cancer cachexia 185
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viii Contents
8. Energy balance and its regulation 187
The concept of energy balance 187
Physiological regulation of energy balance 188
The ‘set point’ theory 189
Is energy expenditure regulated? 189
External influences on food intake 192
Control of energy intake 192
The leptin story 198
9. Obesity 202
Defining obesity 202
Prevalence of obesity 203
Consequences of obesity 211
The metabolic syndrome or ‘syndrome X’ 219
Causes of obesity 219
Prevention and treatment of obesity in populations 229
Obesity treatment in individuals 232
‘Aggressive’ treatments for obesity 237
PART 3 – THE NUTRIENTS
10. Carbohydrates 245
Introduction 245
Nature and classification of carbohydrates 246
Dietary sources of carbohydrates 247
Sugars 248
Artificial sweeteners 250
Diet and dental health 252
Starches 255
Non-starch polysaccharide 257
Resistant starch 260
The glycaemic index 261
Dietary factors in the aetiology of bowel cancer 262
Dietary factors in heart disease 266
11. Protein and amino acids 268
Introduction 268
Chemistry and digestion 268
Intakes, dietary standards and food sources 270
Nitrogen balance 271
Protein quality 274
The significance of protein in human nutrition 278
Concluding remarks 284
12. Fats 285
Nature of dietary fat 285
Types of fatty acid 287
Sources of fat in the human diet 291
Roles of fat in the diet 294
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Contents ix
Blood lipoproteins 300
Digestion, absorption and transport of dietary lipids 301
Transport of endogenously produced lipids 303
The diet–heart hypothesis 304
Fish oils 317
Other natural oils used as supplements 322
13. The micronutrients 324
Scope of this chapter 324
Overview of dietary supplements 325
Food fortification 329
Assessment of the micronutrient adequacy of British adults 330
Anti-oxidants and the oxidant theory of disease 335
Do high anti-oxidant intakes prevent heart disease, cancer and other chronic diseases? 341
Use of substances other than essential nutrients as dietary supplements 346
14. The vitamins 357
General concepts and principles 357
Vitamin A (retinol) 361
Vitamin D (cholecalciferol) 365
Vitamin E (α-tocopherol) 371
Vitamin K (phylloquinone) 372
Thiamin (vitamin B) 374
1
Riboflavin (vitamin B) 376
2
Niacin (vitamin B) 377
3
Vitamin B (pyridoxine) 380
6
Vitamin B (cobalamins) 381
12
Folate or folic acid (vitamin B) 383
9
Biotin 389
Pantothenic acid 389
Vitamin C (ascorbic acid) 390
15. The minerals 393
Introduction 393
Chromium 394
Copper 395
Fluoride 396
Magnesium 396
Manganese 397
Molybdenum 398
Phosphorus 398
Potassium 398
Selenium 399
Zinc 400
Iodine and iodine-deficiency diseases 402
Iron and iron-deficiency anaemia 405
Calcium storage and uptake 410
Calcium and bone health 414
Sodium and disease 421
Review of evidence for a salt–hypertension link 427
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