Barasi’s Human nutrition : a health perspective /

Section I Foods, Nutrient Requirements and Nutrition
Chapter 1 Introduction: What Is Nutrition?...................................................................................3
Aims..............................................................................................................................3
Definitions of Nutrition.................................................................................................3
Evidence-Based Nutrition.........................................................................................4
Why Is Nutrition Important?.........................................................................................4
What Do We Eat?..........................................................................................................6
How Is Information about People’s Diets Collected?....................................................7
Population and Household Information....................................................................7
Studying Nutrition.........................................................................................................8
Summary.......................................................................................................................8
Activity..........................................................................................................................9
Chapter 2 Nutrient Requirements and the Nutritionally Balanced Diet...................................... 11
Aims............................................................................................................................ 11
Diet Quality and the Nutritionally Balanced Diet...................................................... 11
Consumers and Health Claims............................................................................... 11
Nutritionally Balanced Diet: Which Foods to Choose?.............................................. 12
What Is the Difference between Meals and Snacks?............................................. 12
Nutritionally Balanced Diet: How Much to Eat?........................................................ 13
What Are the Features of a Nutritionally Balanced Diet?.......................................... 14
Eating More or Less of Particular Foods............................................................... 14
Eating More or Less of Particular Nutrients.......................................................... 14
Eating Specific Foods That Are Believed to Have ‘Health-Promoting’
Properties................................................................................................................ 15
What Nutrients Are Needed and in What Amounts?.................................................. 15
Nutritional Requirement......................................................................................... 16
Distribution of Nutritional Requirements in a Population.......................................... 17
From Requirements to Recommendations: Dietary Reference Values ...................... 18
Fats and Carbohydrates.......................................................................................... 19
Less-Studied Micronutrients..................................................................................20
Practical Applications.............................................................................................20
For Individuals...................................................................................................20
For Groups of Individuals.................................................................................. 21
For Dietary Planning......................................................................................... 21
Food Labelling................................................................................................... 21
vi Contents
Dietary Planning.........................................................................................................22
Meal Planning Tools...............................................................................................22
Nutrition Information..................................................................................................26
The Question of Alcohol.............................................................................................26
Summary.....................................................................................................................27
Study Questions...........................................................................................................28
Activities.....................................................................................................................28
Bibliography and Further Reading..............................................................................29
Chapter 3 Macronutrients in Foods and Diets: Proteins, Carbohydrates and Fats...................... 31
Aims............................................................................................................................ 31
Proteins........................................................................................................................ 31
Amino Acids: The Building Blocks....................................................................... 32
Proteins in Food.....................................................................................................34
Protein Quality....................................................................................................... 35
Measuring Protein Quality................................................................................ 35
Protein Requirements.............................................................................................36
Carbohydrates.............................................................................................................38
What Are Carbohydrates?......................................................................................38
Monosaccharides............................................................................................... 39
Disaccharides.....................................................................................................40
Oligosaccharides................................................................................................ 41
Polysaccharides.................................................................................................. 41
How Much Carbohydrate Should We Have?.......................................................... 45
Fats.............................................................................................................................. 47
What Are Fats?....................................................................................................... 47
Triglycerides......................................................................................................48
Types of Fatty Acids..........................................................................................49
Essential Fatty Acids......................................................................................... 51
Conjugated Linoleic Acid.................................................................................. 52
Other Lipids....................................................................................................... 53
Fats in the Diet.......................................................................................................54
Sources of Fat in the Diet..................................................................................54
Sources of Essential Fatty Acids....................................................................... 55
Trends in Intakes of Fats.................................................................................... 55
How Much Fat Should We Have in the Diet?.........................................................56
Summary..................................................................................................................... 57
Proteins................................................................................................................... 57
Carbohydrates......................................................................................................... 57
Fats......................................................................................................................... 57
Study Questions........................................................................................................... 58
Activity........................................................................................................................ 58
Bibliography and Further Reading.............................................................................. 58
Chapter 4 Vitamins and Phytochemicals..................................................................................... 61
Aims............................................................................................................................ 61
Vitamins...................................................................................................................... 61
Fat-Soluble Vitamins.............................................................................................. 62
Vitamin A.......................................................................................................... 62
Contents vii
Vitamin D..........................................................................................................64
Vitamin E...........................................................................................................65
Vitamin K..........................................................................................................66
Water-Soluble Vitamins.......................................................................................... 67
Thiamin (Vitamin B1)........................................................................................68
Riboflavin (Vitamin B2).....................................................................................68
Nicotinic Acid (Niacin, Vitamin B3).................................................................69
Vitamin B6......................................................................................................... 70
Folate................................................................................................................. 71
Vitamin B12........................................................................................................ 72
Pantothenic Acid (Vitamin B5).......................................................................... 73
Biotin (Vitamin B7)........................................................................................... 73
Vitamin C.......................................................................................................... 74
Phytochemicals........................................................................................................... 75
Phenolic Compounds, Including Flavonoids.......................................................... 76
Dietary Phytoestrogens.......................................................................................... 76
Phytosterols............................................................................................................77
Glucosinolates........................................................................................................ 78
Carotenoids............................................................................................................. 78
Use of Vitamin and Other Nutritional Supplements................................................... 79
Summary..................................................................................................................... 79
Study Questions...........................................................................................................80
Activity........................................................................................................................80
Bibliography and Further Reading..............................................................................80
Chapter 5 Minerals, Electrolytes and Fluid.................................................................................83
Aims............................................................................................................................83
Minerals......................................................................................................................83
Major Minerals.......................................................................................................85
Calcium..............................................................................................................85
Phosphorus.........................................................................................................86
Magnesium........................................................................................................86
Sulphur...............................................................................................................86
Microminerals or Trace Elements..........................................................................87
Iron.....................................................................................................................87
Zinc....................................................................................................................88
Copper...............................................................................................................88
Selenium............................................................................................................89
Iodine.................................................................................................................89
Chromium..........................................................................................................90
Fluoride..............................................................................................................90
Electrolytes.................................................................................................................. 91
Sodium and Chloride.............................................................................................. 91
Sodium and Chloride in Foods..........................................................................92
Dietary Reference Value....................................................................................92
Potassium................................................................................................................93
Dietary Reference Value....................................................................................93
Potassium in the Diet.........................................................................................93
Fluids: Keeping the Body Hydrated............................................................................93
What to Drink?.......................................................................................................93
viii Contents
Water..................................................................................................................94
Soft Drinks........................................................................................................94
Fruit Juices.........................................................................................................94
Milk...................................................................................................................94
Tea and Coffee...................................................................................................94
How Much to Drink?..............................................................................................94
Water in Foods........................................................................................................94
Dehydration............................................................................................................95
Summary.....................................................................................................................96
Study Questions...........................................................................................................96
Activities.....................................................................................................................96
Bibliography and Further Reading..............................................................................97
Section II Nutrition through the Life Cycle
Chapter 6 Nutrition during Pregnancy and Lactation ��������������������������������������������������������������� 101
Aims.......................................................................................................................... 101
Nutrition before Pregnancy....................................................................................... 102
Nutrition at the Time of Conception......................................................................... 103
Nutrition during Pregnancy....................................................................................... 104
What Are the Dietary Goals in Pregnancy?............................................................. 105
Diet in Pregnancy...................................................................................................... 106
Appetite................................................................................................................ 106
Energy.................................................................................................................. 106
Nutrients............................................................................................................... 106
Food Safety........................................................................................................... 107
Should Supplements Be Given?................................................................................. 108
Who Is Most at Risk in Pregnancy?.......................................................................... 109
Teenage Mothers.................................................................................................. 109
Low Income.......................................................................................................... 109
Underweight and Overweight Women................................................................. 110
Other Situations.................................................................................................... 110
Long-Term Consequences of Intrauterine Events..................................................... 110
Higher Blood Pressure.......................................................................................... 111
Insulin Resistance and Diabetes Mellitus............................................................ 112
Cholesterol Metabolism and Blood Clotting........................................................ 112
Other Conditions.................................................................................................. 113
Nursing or Lactating Mother..................................................................................... 115
Process of Lactation.................................................................................................. 115
Milk Production or Lactogenesis......................................................................... 115
Milk Ejection or Let Down.................................................................................. 115
Diet in Lactation........................................................................................................ 115
Energy.................................................................................................................. 116
Protein.................................................................................................................. 118
General Considerations............................................................................................. 118
Decision to Breastfeed.............................................................................................. 118
Summary................................................................................................................... 119
Contents ix
Study Questions......................................................................................................... 119
Activities................................................................................................................... 119
Bibliography and Further Reading............................................................................ 120
Chapter 7 Nutrition during Infancy, Childhood and Adolescence............................................ 123
Aims.......................................................................................................................... 123
Infants........................................................................................................................ 123
Growth.................................................................................................................. 123
Nutrition and Development.................................................................................. 125
Development of the Digestive Tract................................................................ 125
Energy.............................................................................................................. 126
Protein.............................................................................................................. 127
Fats................................................................................................................... 127
Carbohydrates.................................................................................................. 127
Fluid................................................................................................................. 127
Minerals........................................................................................................... 128
Vitamins.......................................................................................................... 128
Meeting Nutritional Needs................................................................................... 128
Breastfeeding or Bottle-Feeding?............................................................................. 129
Formula Milk and Breast Milk Compared........................................................... 130
Proteins in Milk............................................................................................... 130
Carbohydrates in Milk..................................................................................... 131
Fats in Milk...................................................................................................... 131
Vitamins.......................................................................................................... 131
Minerals........................................................................................................... 131
Immunological Factors.................................................................................... 131
Other Factors................................................................................................... 132
Other Milks Available..................................................................................... 132
Future Health................................................................................................... 132
Weaning..................................................................................................................... 133
Why Should a Baby Be Weaned?......................................................................... 133
Child from 1 to 5 Years of Age................................................................................. 136
School-Age Children................................................................................................. 137
Influences on Nutritional Intakes......................................................................... 137
Autonomy........................................................................................................ 138
Growth............................................................................................................. 138
Activity............................................................................................................ 138
Societal Pressures............................................................................................ 139
Nutritional Needs................................................................................................. 139
What Do Children and Adolescents Eat?.................................................................. 141
Health-Related Aspects........................................................................................ 141
Dietary Patterns.................................................................................................... 141
Nutritional Intakes................................................................................................ 142
School Meals........................................................................................................ 144
Minimum Nutritional Standards..................................................................... 144
Alternatives to School Lunch.......................................................................... 146
Some Potential Nutritional Problems........................................................................ 147
Vegetarianism....................................................................................................... 147
Teenage Athletes.................................................................................................. 148
x Contents
Pregnant Teenagers............................................................................................... 148
Dieting.................................................................................................................. 148
Smoking and Alcohol Use.................................................................................... 149
Summary................................................................................................................... 150
Study Questions......................................................................................................... 150
Activity...................................................................................................................... 150
Bibliography and Further Reading............................................................................ 150
Chapter 8 Nutrition during Adulthood and Ageing................................................................... 153
Aims.......................................................................................................................... 153
Adult Men.................................................................................................................. 154
Do Men Have Problems Achieving These Guidelines and
Are They Appropriate?......................................................................................... 154
Adult Women............................................................................................................. 154
Vegetarians................................................................................................................ 155
Minority Ethnic Groups............................................................................................ 157
Low Income and Nutrition........................................................................................ 158
Characteristics of the Diet.................................................................................... 159
Nutritional Implications....................................................................................... 161
Practical Help....................................................................................................... 162
Older Adults.............................................................................................................. 163
Why Are Some Elderly Persons at Risk?............................................................. 164
Sensory System................................................................................................ 164
Gastrointestinal System................................................................................... 164
Kidney Function.............................................................................................. 165
Lean Tissue...................................................................................................... 165
Mobility........................................................................................................... 165
Immune System............................................................................................... 168
Brain and Nervous System.............................................................................. 168
Other Factors................................................................................................... 169
Factors Affecting Nutritional Status.................................................................... 169
Inadequate Intake............................................................................................ 169
Less Efficient Digestion and Absorption......................................................... 170
Altered Needs.................................................................................................. 170
What Is the Nutritional State of Older Adults?.................................................... 171
What Are the Nutritional Requirements for the Elderly?.................................... 173
Summary................................................................................................................... 175
Study Questions......................................................................................................... 175
Activities................................................................................................................... 176
Bibliography and Further Reading............................................................................ 176
Section III Digestion, Absorption and Nutrient Metabolism
Chapter 9 Gut Structures, Functions and Control of Digestion................................................. 181
Aims.......................................................................................................................... 181
Basic Anatomy and Physiology................................................................................. 181
Contents xi
Functions of the GI Tract.......................................................................................... 182
Digestion............................................................................................................... 183
Secretion............................................................................................................... 183
Motility................................................................................................................. 185
Absorption............................................................................................................ 186
Control of Eating and Digestive Functions............................................................... 186
Sensory Signals.................................................................................................... 188
Pre-Absorptive Information................................................................................. 188
Post-Absorptive Signals........................................................................................ 188
Metabolism........................................................................................................... 189
Integration by the Brain........................................................................................ 190
Summary................................................................................................................... 190
Study Questions......................................................................................................... 190
Activity...................................................................................................................... 191
Bibliography and Further Reading............................................................................ 191
Chapter 10 Digestion and Absorption of Nutrients..................................................................... 193
Aims.......................................................................................................................... 193
Digestion and Absorption of Macronutrients............................................................ 193
Proteins................................................................................................................. 193
Digestion of Proteins....................................................................................... 193
Absorption of the Products of Protein Digestion............................................. 193
Fats....................................................................................................................... 195
Digestion of Fats.............................................................................................. 195
Absorption of the Products of Fat Digestion................................................... 195
Carbohydrates....................................................................................................... 197
Digestion of Carbohydrates............................................................................. 197
Absorption of Carbohydrates........................................................................... 199
Digestion and Absorption of Vitamins..................................................................... 201
Vitamin A............................................................................................................. 201
Vitamin D.............................................................................................................202
Vitamin E.............................................................................................................202
Vitamin K.............................................................................................................202
Thiamin................................................................................................................203
Riboflavin.............................................................................................................203
Niacin...................................................................................................................203
Vitamin B6............................................................................................................203
Folate....................................................................................................................203
Vitamin B12...........................................................................................................203
Vitamin C.............................................................................................................204
Digestion and Absorption of Minerals, Trace Elements and Electrolytes................204
Calcium................................................................................................................204
Enhancing factors............................................................................................204
Inhibitory factors.............................................................................................205
Phosphorus...........................................................................................................206
Magnesium...........................................................................................................206
Iron.......................................................................................................................206
Control of absorption.......................................................................................207
Zinc.......................................................................................................................208
xii Contents
Copper..................................................................................................................208
Selenium...............................................................................................................208
Iodine....................................................................................................................209
Fluoride................................................................................................................209
Sodium and Chloride............................................................................................209
Potassium..............................................................................................................209
Fluid Balances................................................................................................. 210
Digestion and Absorption of Phytochemicals........................................................... 212
Summary................................................................................................................... 213
Study Questions......................................................................................................... 214
Activity...................................................................................................................... 214
Bibliography and Further Reading............................................................................ 214
Chapter 11 Metabolism and Function of Macronutrients............................................................ 215
Aims.......................................................................................................................... 215
Proteins...................................................................................................................... 215
Amino Acid Metabolism........................................................................................... 215
Amino Acid Pool.................................................................................................. 216
Control of Protein Metabolism............................................................................. 218
Contribution of Protein to Body Composition................................................. 218
Formation of Enzymes.................................................................................... 219
Homeostasis..................................................................................................... 219
Hormones......................................................................................................... 219
Acid–Base Balance.......................................................................................... 219
Fluid Balance................................................................................................... 219
Immunity......................................................................................................... 219
Transport.......................................................................................................... 219
Blood Clotting.................................................................................................220
Other Functions...............................................................................................220
Fats............................................................................................................................220
Metabolic Roles....................................................................................................220
Meeting the Energy Needs: Fat Metabolism...................................................220
Fat Requires Specialized Proteins for Transport around the Body................. 221
Storage: The Adipose Tissue...........................................................................223
Adipose Tissue and Metabolic Regulation......................................................224
Fat Utilization..................................................................................................224
Functions of Fat in the Body...........................................................................225
Structure of Membranes..................................................................................226
Link with Glucose Metabolism: Insulin Resistance........................................226
Steroid Metabolism..........................................................................................226
Essential Fatty Acids.......................................................................................226
Carbohydrates...........................................................................................................228
Carbohydrates Metabolism...................................................................................229
Carbohydrate Storage...........................................................................................229
Glycogenesis....................................................................................................229
Lipogenesis......................................................................................................229
Mobilization of Carbohydrates.............................................................................229
Glycogenolysis/Glycolysis...............................................................................229
Gluconeogenesis..............................................................................................230
Contents xiii
Metabolic Consequences of Sugar Intake....................................................... 231
Other Physiological Roles of Carbohydrates................................................... 231
Gut Health........................................................................................................ 231
Summary................................................................................................................... 233
Study Questions......................................................................................................... 233
Bibliography and Further Reading............................................................................ 233
Chapter 12 Metabolism and Function of Micronutrients............................................................. 235
Aims.......................................................................................................................... 235
Vitamins.................................................................................................................... 235
Vitamin A............................................................................................................. 235
Vision...............................................................................................................236
Cellular Differentiation.................................................................................... 237
Growth.............................................................................................................238
Antioxidant Role..............................................................................................238
Other Functions...............................................................................................238
Vitamin D.............................................................................................................238
Vitamin E............................................................................................................. 239
Vitamin C.............................................................................................................240
Vitamin K.............................................................................................................240
Thiamin (Vitamin B1)........................................................................................... 241
Riboflavin (Vitamin B2)....................................................................................... 241
Niacin (Vitamin B3).............................................................................................. 241
Pyridoxine (Vitamin B6)......................................................................................242
Folate (Vitamin B9)..............................................................................................242
Cobalamin (Vitamin B12)..................................................................................... 243
Pantothenic Acid (Vitamin B5)............................................................................. 243
Biotin (Vitamin B7)..............................................................................................244
Minerals....................................................................................................................244
Calcium................................................................................................................244
In Bones...........................................................................................................244
In Blood and Body Fluids................................................................................244
Why Does Plasma Calcium Need to Be Closely Regulated?..........................246
Phosphorus...........................................................................................................246
Magnesium...........................................................................................................246
Iron....................................................................................................................... 247
Losses of Iron.................................................................................................. 247
Stored Iron....................................................................................................... 247
Zinc.......................................................................................................................248
Copper..................................................................................................................248
Selenium...............................................................................................................249
Iodine....................................................................................................................249
Chromium.............................................................................................................250
Sodium, Chloride and Potassium.........................................................................250
Summary................................................................................................................... 251
Study Questions......................................................................................................... 251
Activities................................................................................................................... 252
Bibliography and Further Reading............................................................................ 252
xiv Contents
Section IV Eating Behaviour and Nutritional Epidemiology
Chapter 13 Habits and Influences on Eating Behaviours............................................................ 255
Aims.......................................................................................................................... 255
Reasons for Eating.................................................................................................... 255
Habit as an Influence on Eating Behaviour.......................................................... 255
Psychological Drivers for Eating..........................................................................256
Sensory Appeal....................................................................................................256
Social Influence.................................................................................................... 257
Food Habits............................................................................................................... 258
Acquisition of Food Habits................................................................................... 259
Changing Food Habits.......................................................................................... 259
Food Choices........................................................................................................260
Availability........................................................................................................... 261
Physical/Environmental Factors...................................................................... 261
Legislative Factors........................................................................................... 262
Affordability, Cost and Taxation..................................................................... 262
Accessibility.................................................................................................... 262
Acceptability........................................................................................................263
Cultural Factors...............................................................................................263
Physiological Factors.......................................................................................264
Social/Psychological Influences......................................................................265
Summary................................................................................................................... 267
Study Questions......................................................................................................... 267
Activities................................................................................................................... 267
Bibliography and Further Reading............................................................................268
Chapter 14 Diet and Coronary Heart Disease.............................................................................269
Aims..........................................................................................................................269
Changes in Rates of Cardiovascular Disease............................................................ 270
What Is Coronary Heart Disease?............................................................................. 270
Injury to the Coronary Arteries............................................................................ 271
Fibrous Plaque Formation.................................................................................... 271
Thrombosis and Heart Attack.............................................................................. 271
Studying Coronary Heart Disease............................................................................ 273
Origins of the Lipid Hypothesis........................................................................... 273
Cross-Community Comparisons..................................................................... 273
Prospective Studies.......................................................................................... 274
Intervention Studies......................................................................................... 274
Risk Factors............................................................................................................... 276
Genetic Predisposition..........................................................................................277
Age........................................................................................................................277
Social Conditions and Social Inequality..............................................................277
Birthweight........................................................................................................... 278
Geographical Location and Sunlight................................................................... 278
Disease.................................................................................................................. 279
Smoking................................................................................................................ 279
Contents xv
High Blood Pressure.............................................................................................280
Raised Blood Lipids.............................................................................................280
Weight...................................................................................................................280
Physical Activity................................................................................................... 281
Psychosocial Factors............................................................................................. 281
Dietary Factors..................................................................................................... 281
Fats...................................................................................................................282
Total Energy....................................................................................................285
Salt...................................................................................................................285
Calcium............................................................................................................286
Alcohol............................................................................................................286
Fibre (Non-Starch Polysaccharides)................................................................286
Antioxidants.....................................................................................................287
Homocysteine and Folate.................................................................................289
Future Directions.......................................................................................................290
Summary...................................................................................................................290
Study Questions.........................................................................................................290
Bibliography and Further Reading............................................................................290
Chapter 15 Diet and Cancer.........................................................................................................293
Aims..........................................................................................................................293
What Is Cancer?........................................................................................................294
Studying the Relationship between Diet and Cancer................................................294
Ecological or Correlational Studies...................................................................... 295
Case–Control Studies........................................................................................... 295
Prospective Cohort Studies..................................................................................296
Meta-Analysis.......................................................................................................296
Environmental Causes of Cancer..............................................................................296
Role of Diet...........................................................................................................297
Possible Promoting Factors..................................................................................298
Total Energy Intake.........................................................................................298
Fat Intakes........................................................................................................298
Alcohol............................................................................................................299
Salt...................................................................................................................300
Meat and Fish..................................................................................................300
Other Promoters of Cancer.............................................................................. 301
Possible Protective Factors................................................................................... 301
Nonstarch Polysaccharides (Dietary Fibre).....................................................302
Fruit and Vegetables........................................................................................303
Antioxidant Nutrients......................................................................................303
Other Chemically Active Constituents............................................................304
Calcium............................................................................................................304
Prevention of Cancer.................................................................................................305
Summary...................................................................................................................308
Study Questions.........................................................................................................308
Activities...................................................................................................................308
Bibliography and Further Reading............................................................................309
xvi Contents
Section V Dietary and Nutritional Assessment
Chapter 16 Energy: Intake and Expenditure............................................................................... 313
Aims.......................................................................................................................... 313
Units of Measurement of Energy.............................................................................. 313
Energy Intake............................................................................................................ 314
Energy Content of Foods...................................................................................... 314
Bomb Calorimeter........................................................................................... 314
Proximate Principles........................................................................................ 315
Dietary Assessment.............................................................................................. 317
Contribution from Food Groups...................................................................... 317
Energy Output........................................................................................................... 318
Basal Metabolic Rate............................................................................................ 318
Influence of Body Weight................................................................................ 320
Influence of Gender......................................................................................... 320
Influence of Age.............................................................................................. 320
Influence of Disease Status.............................................................................. 320
Thermogenesis...................................................................................................... 321
Physical Activity................................................................................................... 321
Measurement of Energy Output........................................................................... 322
Direct Calorimetry..........................................................................................324
Indirect Methods..............................................................................................324
Calculation of Energy Expenditure........................................................................... 325
Calculation of 24-Hour Energy Expenditure: An Example................................. 326
Summary................................................................................................................... 327
Study Questions......................................................................................................... 327
Activities................................................................................................................... 327
Bibliography and Further Reading............................................................................ 329
Chapter 17 Energy Balance......................................................................................................... 331
Aims.......................................................................................................................... 331
Energy Balance......................................................................................................... 331
Influences on Energy Intake................................................................................. 332
Influences on Energy Output................................................................................ 332
Adaptations to Basal Metabolic Rate.............................................................. 332
Adaptations to Thermogenesis........................................................................ 333
Adaptations to Physical Activity..................................................................... 334
How Well Is Energy Balance Controlled?................................................................ 335
Control Mechanisms............................................................................................. 335
Energy Balance and Imbalance................................................................................. 337
Negative Energy Balance..................................................................................... 337
The Fasted State................................................................................................... 338
Starvation.............................................................................................................. 338
Positive Energy Balance....................................................................................... 339
Energy Balance and Body Composition...............................................................340
Summary................................................................................................................... 341
Study Questions......................................................................................................... 341
Bibliography and Further Reading............................................................................ 341
Contents xvii
Chapter 18 Dietary and Nutritional Assessment......................................................................... 343
Aims.......................................................................................................................... 343
Nutritional Status...................................................................................................... 343
What We Eat: Diet Composition.......................................................................... 343
What We Are: Body Composition........................................................................ 343
What We (Can) Do: Function...............................................................................344
What We Pass On.................................................................................................344
What We Eat: Dietary Assessment...........................................................................344
The Weighed Inventory (or Weighed Dietary Record)........................................344
Food Diaries (or Estimated Dietary Records)...................................................... 345
Food Frequency Questionnaires (FFQs).............................................................. 345
The Diet Interview................................................................................................346
Practical Issues in Dietary Assessment Methods.................................................346
Misreporting....................................................................................................346
Measurement Errors, Bias and Precision......................................................... 347
Validity............................................................................................................ 347
What We Are: Body Composition.............................................................................348
Measuring Body Composition..................................................................................348
Body Mass Index..................................................................................................348
Skinfold and Skeletal Measurements................................................................... 350
Anthropometry..................................................................................................... 351
Underwater Weighing........................................................................................... 353
Other Indirect Methods........................................................................................ 353
Bioelectrical Impedance.................................................................................. 353
Ultrasound....................................................................................................... 353
Other Techniques............................................................................................. 354
What Are the Average Values for Body Composition?............................................. 354
What We Can Do: Functional Capacity.................................................................... 354
Biochemical Indicators.............................................................................................. 355
Clinical Indicators..................................................................................................... 355
What Can We Learn from Nutritional Assessment?................................................. 356
How Is Nutritional Status Information Used?........................................................... 357
Summary................................................................................................................... 357
Study Questions......................................................................................................... 358
Activity...................................................................................................................... 358
Bibliography and Further Reading............................................................................ 358
Section VI Applied Nutrition
Chapter 19 Introduction to Public Health Nutrition and Health Promotion................................ 363
Aims.......................................................................................................................... 363
What Is the Basis of Health-Promoting Policies and What Is Proposed?.................366
Dietary Links.......................................................................................................366
Lifestyle and Social Factors.................................................................................366
Undernutrition, Malnutrition and the Double Burden of Disease in
Developing Countries...........................................................................................369
From Goals to Guidelines....................................................................................369
xviii Contents
What Is Health Promotion?....................................................................................... 371
Planning................................................................................................................ 372
Intervention........................................................................................................... 373
Evaluation............................................................................................................. 374
Health-Promotion Initiatives and the Individual....................................................... 375
Information and Education................................................................................... 375
Schools.................................................................................................................. 376
The NHS and Health Professionals...................................................................... 376
Media/Advertising................................................................................................ 376
The Food Chain.................................................................................................... 377
Constraints............................................................................................................ 377
A Targeted Policy................................................................................................. 377
Economics of Health Promotion............................................................................... 379
Summary...................................................................................................................380
Study Questions.........................................................................................................380
Activities................................................................................................................... 381
Bibliography and Further Reading............................................................................ 381
Chapter 20 Introduction to Obesity and Weight Management.................................................... 383
Aims.......................................................................................................................... 383
Obesity: What Are the Reasons?............................................................................... 383
Dietary Intake: Energy Consumption and Obesity.............................................. 385
Physical Activity................................................................................................... 388
Genetic Predisposition..........................................................................................388
Age and Gender.................................................................................................... 389
Socio-Economic status.............................................................................................. 389
Psychological Factors...........................................................................................390
Health Risks and Costs of Overweight and Obesity.................................................390
Treatment of Obesity/Overweight............................................................................. 392
Energy-Controlled Diets....................................................................................... 393
Pharmacological Agents....................................................................................... 394
Surgical Intervention (‘Bariatric Surgery’).......................................................... 395
Psychological and Behavioural Therapy.............................................................. 395
Physical Activity................................................................................................... 395
Unsafe Methods of Weight Loss.......................................................................... 396
Summary................................................................................................................... 396
Study Questions.........................................................................................................397
Activity......................................................................................................................397
Bibliography and Further Reading............................................................................397
Chapter 21 Introduction to Clinical Nutrition.............................................................................399
Aims..........................................................................................................................399
Negative Energy Balance..........................................................................................400
Weight Loss Due to Illness................................................................................... 401
Correcting Weight Loss........................................................................................ 401
Starvation and Refeeding.....................................................................................402
Malnutrition Screening and Diagnosis......................................................................403
Screening Tools....................................................................................................403
Nutritional Support: Enteral and Parenteral Feeding................................................405
Contents xix
Clinical Micronutrient Deficiencies..........................................................................406
Adverse Reactions to Food........................................................................................406
Food Poisoning.....................................................................................................407
Food Aversion.......................................................................................................407
Food Intolerance...................................................................................................408
Why Do Some Individuals Develop Food Allergy? Atopy............................. 410
Diagnosis.............................................................................................................. 411
Effect of Infection on Nutritional Status.............................................................. 412
Effect of Nutritional Status on Immunity............................................................. 413
Nutrition Management and Cancer...................................................................... 414
Nutrition Management and Metabolic Disorders................................................. 414
Drug–Nutrient Interactions....................................................................................... 414
Effects of Diet on Drugs....................................................................................... 415
Dietary Factors Affecting Drug Metabolism.................................................. 415
Dietary Factors Affecting Drug Excretion...................................................... 415
Drug Effects on Food Intake........................................................................... 415
Gastro-Intestinal Function............................................................................... 415
Metabolic Effects of Drugs on Nutrients......................................................... 416
Influence of Disability on Nutrition.......................................................................... 416
Appetite................................................................................................................ 417
Ability to Obtain and Prepare Food..................................................................... 417
Ability to Ingest, Chew and Swallow Food.......................................................... 417
Impact on Digestion and Absorption.................................................................... 417
Impact on Metabolism.......................................................................................... 418
Nutritional Consequences..................................................................................... 418
Eating Disorders........................................................................................................ 418
Summary................................................................................................................... 419
Study Questions......................................................................................................... 419
Bibliography and Further Reading............................................................................ 419
Chapter 22 Introduction to Sport Nutrition.................................................................................. 421
Aims.......................................................................................................................... 421
Nutrition and the Athlete........................................................................................... 421
Energy Needs in Sport......................................................................................... 422
Energy as Adenosine Triphosphate (ATP)........................................................... 422
Energy from Fat and Carbohydrates.................................................................... 423
During Training............................................................................................... 425
After Exercise.................................................................................................. 425
Protein Needs....................................................................................................... 426
Dietary Supplements............................................................................................ 427
Vitamin and Mineral Supplements.................................................................. 427
Creatine............................................................................................................ 427
Fluid...................................................................................................................... 428
Sports Products..................................................................................................... 429
Summary................................................................................................................... 429
Study Questions......................................................................................................... 430
Activities................................................................................................................... 430
Bibliography and Further Reading............................................................................ 430
xx Contents
Chapter 23 Improving Foods for Better Nutrition....................................................................... 431
Aims.......................................................................................................................... 431
Foods, Food Components and Health Claims........................................................... 432
Terminology......................................................................................................... 433
Smart Foods.............................................................................................................. 433
Foods with Novel Molecular Structures............................................................... 433
Meat Analogues.................................................................................................... 434
Foods Produced by Biotechnology....................................................................... 434
Functional Foods.................................................................................................. 435
Fortified Foods..................................................................................................... 435
Reduced Content of Nutrients......................................................................... 436
Foods Containing Phytochemicals.................................................................. 436
Foods with Added Components...................................................................... 436
Omega-Enriched Eggs..................................................................................... 437
Clinical Usage.................................................................................................. 437
Foods Containing Bacteria.............................................................................. 437
Food Reformulation.................................................................................................. 439
Nutrient Profiling...................................................................................................... 441
Organic Food.............................................................................................................442
Conclusions...............................................................................................................443
Summary...................................................................................................................443
Study Questions.........................................................................................................443
Activities...................................................................................................................444
Bibliography and Further Reading............................................................................444
Index...............................................................................................................................................447