Nutrition

2020·English

by  Geoffrey P. Webb

Cover Page: i
Half-Title Page: i
Title Page: iii
Copyright Page: iv
Dedication Page: iv
Contents Page: vii
Preface Page: xxii
Acknowledgement Page: xxvi
About the author Page: xxviii
PART 1 CONCEPTS AND PRINCIPLES Page: xxx
1 Changing priorities in nutrition Page: 2
Ensuring adequacy and use of food groups Page: 3
A new priority – reducing the chronic diseases of ageing populations Page: 6
Plates and pyramids: food guides to reflect modern nutritional priorities Page: 7
Failure to fully implement better nutritional knowledge and understanding Page: 9
The future of nutrition research Page: 12
Yoghurt and ovarian cancer? A case study of unproductive research Page: 14
Key reference Page: 18
2 Food selection Page: 18
Introduction and aims of the chapter Page: 19
The biological model of food Page: 20
Dietary and cultural prejudice Page: 21
Food classification systems Page: 22
Nutritional classification Page: 22
Consumer classification Page: 23
Anthropological classification of foods Page: 25
Non-nutritional uses of food Page: 27
Religion, morality and ethics Page: 27
Status and wealth Page: 27
Interpersonal relationships Page: 27
Political Page: 28
Folk medicine Page: 28
The hierarchy of human needs Page: 28
A model of food selection – “The hierarchy of availabilities model” Page: 30
Physical availability Page: 32
Economic availability Page: 32
International trends Page: 33
The problem of feeding the world Page: 34
Effects of income upon food selection in the UK Page: 36
Cultural availability Page: 37
Dietary taboos Page: 38
Effects of migration upon eating habits Page: 40
“Gatekeeper” limitations on availability Page: 43
A social–ecological model for food and activity decisions Page: 45
Key references Page: 46
3 Methods of nutritional assessment and surveillance Page: 46
Aims and introduction Page: 47
Strategies for nutritional assessment Page: 47
The general lack of valid and reliable measurements in nutrition Page: 48
Measurement of food intake Page: 49
Population or group methods Page: 49
Individual methods Page: 53
Retrospective methods Page: 53
Prospective methods Page: 54
Doubly labelled water (DLW) Page: 56
Tables of food composition Page: 58
Food table problems and errors Page: 58
Dietary standards and nutrient requirements Page: 60
Origins of dietary standards Page: 60
Definitions and explanations Page: 60
The uses of dietary standards Page: 63
Inaccurate standards Page: 64
Defining requirement Page: 65
Deprivation studies Page: 66
Radioactive tracer studies Page: 66
Balance studies Page: 67
Factorial methods Page: 67
Measurement of blood or tissue levels Page: 68
Biochemical markers Page: 68
Biological markers Page: 69
Animal experiments Page: 69
Clinical signs for the assessment of nutritional status Page: 70
Anthropometric assessment in adults Page: 71
Uses of anthropometric assessment Page: 72
Height and weight Page: 73
The Body Mass Index Page: 73
Alternatives to height Page: 74
Skinfold calipers Page: 74
Bioelectrical impedance (BIA) Page: 75
Estimation of fatness from body density Page: 76
An alternative method of measuring body volume (air displacement plethysmography or Bod Pod) Page: 76
Body water content as a predictor of body fat content Page: 76
Mid-arm circumference measures Page: 77
Anthropometric assessment in children Page: 77
Body mass index in children Page: 78
Estimating fatness in animals Page: 80
Biochemical assessment of nutritional status Page: 81
Measurement of energy expenditure and metabolic rate Page: 83
Comparisons of metabolic rates between individuals Page: 85
Key references Page: 86
4 Investigating links between diet and health outcomes Page: 88
Aims and scope of the chapter Page: 89
Observation vs experimentation Page: 89
Range and classification of the methods available Page: 90
About statistics Page: 92
Observational human studies Page: 94
Geographical comparisons Page: 94
Anomalous populations Page: 95
Special groups Page: 95
Time trends Page: 95
Migration studies Page: 96
Cross-sectional surveys Page: 96
“Experiments” of nature Page: 97
Case-control studies Page: 97
Cohort studies Page: 98
Association in observational studies does not prove cause and effect Page: 99
Criteria for establishing cause and effect Page: 101
Animal and in vitro experiments Page: 102
Role of animal and in vitro experiments Page: 102
Animal use in UK experiments Page: 104
The rationale for using non-human species in medical research Page: 104
In vitro experiments Page: 104
Animal experiments Page: 105
The potential of animal experiments to mislead human biologists Page: 105
Different strategies of mice and people during cold exposure Page: 106
The nutritional burden of pregnancy in mice and people Page: 107
Species vary in the nutrients they require and their response to foreign chemicals Page: 107
Human experimental studies Page: 108
General design aims of human experimental studies Page: 108
Classifying human experiments Page: 108
Important technical terms Page: 109
Random allocation Page: 109
Double-blind, placebo-controlled Page: 109
Crossover design vs parallel design Page: 110
Risk factors and risk markers Page: 110
Compliance and contamination Page: 111
Some examples of human experimental studies Page: 112
Watercress and cancer Page: 112
Echinacea and cold symptoms Page: 113
Fluoridated water and dental caries in children Page: 113
Folic acid supplements and neural tube defects Page: 113
Vitamin E (alpha-tocopherol), beta-carotene and the risk of lung cancer Page: 113
Scoring clinical trials for quality Page: 114
A warning about uncontrolled trials Page: 114
Key references Page: 116
5 Investigating links between diet and health – amalgamation, synthesis and decision making Page: 116
Aims and scope of the chapter Page: 117
Meta-analysis Page: 117
What is it? Page: 117
Growth of meta-analysis Page: 118
Summarising the results of a meta-analysis Page: 119
Some general problems with meta-analysis Page: 120
Decision-making and hierarchies of evidence Page: 121
The basic dilemma Page: 121
Harm from intervention based on inadequate evidence? Page: 122
Harm from unduly delayed intervention? Page: 122
Evidence hierarchies Page: 123
National Institute for Health and Clinical Excellence (NICE) Page: 126
The need to be critical of the latest published research findings Page: 127
Why are so many research findings irreproducible? Page: 128
Bias Page: 129
The pressure to achieve statistical significance Page: 129
Selective exclusion/inclusion of outlying results Page: 130
Multiple analyses Page: 130
Underpowered studies Page: 131
Small effect size Page: 131
Multiple modelling Page: 132
Randomised controlled trials, the gold standard of evidence? Page: 132
Are meta-analyses the platinum standard? Page: 134
A footnote about research fraud Page: 136
Key references Page: 139
6 Dietary guidelines and recommendations Page: 140
The range of “expert reports” and their consistency Page: 141
Variations in the presentation of guidelines and recommendations Page: 144
“Food” recommendations Page: 145
Energy and body weight Page: 146
Recommendations for fats, carbohydrates, protein and salt Page: 146
UK Targets Page: 146
Rationale Page: 147
Alcohol Page: 148
Changing UK alcohol recommendations Page: 149
What do these guidelines mean in terms of real-life behaviour? Page: 149
How does current consumption compare to the new guidelines? Page: 149
The economic impacts of alcohol Page: 150
The (apparent) alcohol–mortality J-curve? Page: 151
Alcohol increases risk of cancer, liver disease and accidental death Page: 152
Why are the 1995 and 2016 conclusions so different? Page: 153
Summing up the alcohol debate Page: 155
How do current UK diets compare with “ideal” intakes? Page: 156
Willingness to change Page: 157
Some barriers to dietary change Page: 158
Aids to food selection Page: 160
Concluding remarks Page: 161
Key references Page: 164
PART 2 ENERGY, ENERGY BALANCE AND OBESITY Page: 164
7 Introduction to energy aspects of nutrition Page: 166
Units of energy Page: 167
How are energy requirements estimated? Page: 168
Variation in average energy requirements – general trends Page: 170
The energy content of foods Page: 172
Sources of dietary energy by nutrient Page: 173
Energy density Page: 176
Nutrient density Page: 178
The sources of dietary energy by food groups Page: 179
Starvation Page: 180
The immediate causes of starvation Page: 180
Physiological responses and adaptations Page: 180
Some adverse consequences of starvation Page: 182
Eating disorders Page: 183
Anorexia nervosa: Characteristics and consequences Page: 183
Bulimia nervosa and binge eating disorder Page: 184
Incidence of eating disorders Page: 185
Causes of eating disorders Page: 185
Cachexia Page: 187
Cancer anorexia cachexia syndrome Page: 187
Key references Page: 190
8 Energy balance and its regulation Page: 190
Concept of energy balance Page: 191
Is there physiological regulation of energy balance? Page: 193
“Set point” theory Page: 193
External influences that affect food intake Page: 194
Physiological regulation of energy intake Page: 194
Early work with experimental animals Page: 194
Hypothalamic centres controlling feeding – a more recent perspective Page: 195
Gut-fill cues Page: 197
The glucostat theory Page: 198
The lipostat or adipostat theory Page: 198
The leptin story Page: 200
Is energy expenditure regulated? Page: 203
Key references Page: 208
9 Obesity Page: 208
Defining obesity Page: 209
Prevalence of overweight and obesity Page: 210
A worldwide perspective Page: 212
Effects of ethnicity and social status upon obesity prevalence Page: 214
Overweight and obesity in children Page: 217
The consequences of obesity Page: 220
The relationship between BMI and life expectancy Page: 220
Obesity and the quality of life Page: 222
Not all body fat is equally bad Page: 224
Weight cycling Page: 225
Does high BMI directly cause an increase in mortality? Page: 225
The metabolic syndrome or “syndrome X” Page: 228
The causes of obesity Page: 228
Nature or nurture? Page: 229
A weakening link between hunger and eating? – The internal/external hypothesis and behaviour therapy Page: 230
Variety of food and sensory specific satiety Page: 232
Is fat more fattening than carbohydrate? Page: 233
Inactivity as a cause of obesity Page: 235
Prevention and treatment of obesity in populations Page: 237
Adopting a “low-risk” lifestyle Page: 237
Targeting anti-obesity measures or campaigns Page: 239
Obesity treatment in individuals Page: 240
Realistic rates of weight loss Page: 240
The reducing diet Page: 241
Alternative diets Page: 241
The role of exercise Page: 242
Are the obese less “vigilant”? Page: 244
More “aggressive” treatments for obesity Page: 245
Drug therapy Page: 245
Appetite suppressants Page: 245
Drugs that block digestion Page: 246
Drugs based on gut hormones Page: 247
Drugs that increase energy expenditure Page: 247
Leptin and leptin analogues Page: 247
Surgical treatment for obesity Page: 247
Very Low Energy Diets (VLEDs) Page: 248
Use of these more extreme treatments Page: 249
Key references Page: 250
PART 3 THE NUTRIENTS Page: 252
10 Carbohydrates Page: 254
Introduction Page: 255
Nature, classification and metabolism of carbohydrates Page: 256
Aerobic metabolism of pyruvic acid Page: 258
Dietary sources of carbohydrate Page: 258
Sugars Page: 259
Lactose or milk sugar Page: 260
Sucrose Page: 260
The new UK “sugar tax” Page: 261
Artificial sweeteners Page: 263
“Calorie-free” sweeteners Page: 263
Sugar replacers Page: 265
Diet and dental health Page: 266
Starches Page: 269
Dietary fibre/NSP Page: 270
Resistant starch Page: 274
The glycaemic index (GI) and glycaemic load (GL) Page: 276
Dietary fibre and other factors in the aetiology of bowel cancer and heart disease Page: 277
Background Page: 277
Possible mechanisms by which dietary factors may affect bowel cancer risk Page: 278
Descriptive epidemiology Page: 278
Case-control and cohort studies Page: 280
What about fibre and heart disease? Page: 280
Key references Page: 282
11 Protein and amino acids Page: 284
Traditional scientific aspects of protein nutrition Page: 285
Introduction Page: 285
Chemistry, digestion and metabolism Page: 285
Amino acid metabolism Page: 287
Intakes, dietary standards and food sources Page: 288
Nitrogen balance Page: 289
Estimation of protein content Page: 289
The concept of nitrogen balance Page: 289
Negative nitrogen balance Page: 289
Requirements for balance Page: 290
Positive nitrogen balance Page: 290
Dietary adequacy for protein is not a major issue Page: 291
Protein quality Page: 293
Essential amino acids Page: 293
Establishing the essential amino acids and quantifying requirements Page: 294
Limiting amino acid Page: 294
First- and second-class proteins Page: 294
Mutual supplementation of protein Page: 295
Measurement of protein quality Page: 295
Do children need more protein than adults? Page: 296
Absolute requirement Page: 296
The relative requirement Page: 297
The protein level/concentration needed in the diet Page: 297
Reasons why the past protein needs of children were exaggerated (personal interpretation) Page: 298
Protein quality is probably of little significance in human nutrition Page: 299
Conclusions Page: 299
The protein gap – one of the biggest errors in nutritional science? Page: 299
Overview Page: 299
Aims of this section Page: 300
Past belief in a protein gap and major initiatives taken to close this gap Page: 300
The concept of a protein gap loses credibility Page: 301
What caused the protein gap mistake? Page: 302
Exaggerated estimates of the protein needs of children Page: 302
Kwashiorkor, due to primary protein deficiency, is the dominant form of worldwide malnutrition? Page: 303
Lasting impact of the protein gap myth Page: 303
Concluding remarks Page: 306
Key references Page: 306
12 Fat Page: 306
Nature of dietary fat Page: 307
Types of fatty acids Page: 309
Saturated fatty acids Page: 309
Monounsaturated fatty acids Page: 309
Polyunsaturated fatty acids Page: 309
Cis/trans isomerisation Page: 310
Effects of chain length and degree of unsaturation upon fatty acid melting points Page: 310
Conjugated linoleic acid (CLA) Page: 311
Distribution of fatty acid types in dietary fat Page: 312
Polyunsaturates: saturates (P:S) ratio Page: 313
Sources of fat in the diet Page: 314
UK fat intakes and their food sources Page: 315
Roles of fat in the diet Page: 316
Fat as an energy source Page: 316
Palatability Page: 317
Satiation Page: 318
Fat-soluble vitamins Page: 318
Essential fatty acids Page: 319
Essential fatty acids and eicosanoid production Page: 320
Blood lipoproteins Page: 322
Digestion, absorption and transport of dietary lipids Page: 323
Transport of endogenously produced lipids Page: 324
Fat metabolism Page: 326
Statins Page: 326
The “diet-heart hypothesis” and its implication for dietary fats Page: 329
Current “health images” of different dietary fats Page: 332
What about saturated vegetable fats like coconut and palm oil? Page: 333
Trans-fatty acids Page: 334
Plant sterols Page: 335
Review of the evidence for the diet-heart hypothesis Page: 336
The key tenets of the diet-heart hypothesis Page: 336
Evidence overview Page: 337
Experimental studies Page: 337
“Experiments of nature” Page: 337
Cohort studies Page: 338
Intervention trials and clinical trials Page: 338
Fish oils Page: 340
Overview Page: 340
How might fish oils exert beneficial health effects? Page: 340
Evidence that high fish oil consumption may reduce CHD Page: 341
Conclusions and fish consumption recommendations Page: 342
Other natural oils used as supplements Page: 343
Key references Page: 344
13 Dietary supplements and food fortification Page: 346
An overview of food fortification Page: 347
Definitions Page: 347
Early successes Page: 348
Fortification in the UK Page: 348
Folic acid (vitamin B9) in flour – a modern fortification success story Page: 348
Time to update UK food fortification policy Page: 351
An overview of dietary supplements Page: 353
Definition and categories of dietary supplements Page: 353
Size and breakdown of the supplement market Page: 354
Overview of uses and potential hazards Page: 354
Some rules and regulations Page: 355
Vitamin and mineral supplements Page: 357
Do vitamin and mineral supplements ensure adequacy? Page: 357
Do micronutrient supplements reduce cancer, cardiovascular disease and increase life expectancy? Page: 359
Do individual micronutrient supplements offer specific benefits? Page: 359
Strategies for improving micronutrient adequacy Page: 363
Natural fats and oils Page: 364
The main “natural oil” supplements Page: 364
Evening primrose and starflower/borage oils Page: 364
Fish oils Page: 365
Dietary supplements or natural medicines? Page: 366
Natural metabolites as dietary supplements Page: 368
Conditionally essential nutrients Page: 368
L-Carnitine Page: 369
Glucosamine and Chondroitin sulphate Page: 369
Co-enzyme Q10(CoQ10) or ubiquinone Page: 370
Creatine Page: 371
Alpha (α)-lipoic acid Page: 371
Lecithin and choline Page: 372
s-Adenosylmethionine Page: 372
Natural extracts as dietary supplements Page: 373
Secondary metabolites in plant extracts Page: 373
Role of plant secondary metabolites in preventing/treating disease Page: 375
Phytoestrogens Page: 376
Garlic supplements Page: 377
Others Page: 378
Antioxidants and the oxidant theory of disease Page: 379
The nature and effects of free radicals Page: 379
Origins of free radicals Page: 379
Physiological mechanisms to limit free radical damage Page: 380
Situations that might increase damage by free radicals Page: 381
Do high antioxidant intakes prevent heart disease, cancer and other chronic diseases? Page: 384
Key references Page: 388
14 Food as medicine Page: 390
Fruit and vegetables five, seven, ten or even three portions per day? Page: 391
Background Page: 391
A flavour of the evidence underpinning the 5-a-day recommendation Page: 392
Calls to change the 5-a-day recommendation Page: 393
Can we justify increasing the 5-a-day recommendations? Page: 397
Is 10-a-day a realistic recommendation? Page: 397
Superfoods Page: 398
What are “superfoods”? Page: 398
What is the theoretical basis of claims for superfoods? Page: 399
Examples of superfoods Page: 400
The choice of which foods to classify as superfoods is biased Page: 402
Conclusions Page: 402
Functional foods Page: 403
Phytoestrogens Page: 404
Probiotics, prebiotics and synbiotics Page: 405
Plant sterols or phtyosterols Page: 408
Key references Page: 410
15 The vitamins Page: 412
Some general concepts and principles Page: 413
What is a vitamin? Page: 413
Classification Page: 414
Vitamin deficiency diseases Page: 415
Precursors and endogenous synthesis of vitamins Page: 416
Circumstances that precipitate deficiency Page: 416
A note about individual vitamins Page: 417
Vitamin A – retinol Page: 417
Key facts Page: 417
Nature and sources of vitamin A Page: 418
Functions Page: 419
Requirements and assessment of vitamin A status Page: 420
Deficiency states Page: 420
Risk factors for deficiency Page: 421
Benefits and risks of high intakes Page: 421
Vitamin D – cholecalciferol Page: 421
Key facts Page: 421
Nature, sources and requirements for vitamin D Page: 422
Functions of vitamin D Page: 424
Acute deficiency states Page: 425
Vitamin D, osteoporosis and non-bone conditions Page: 426
Safely improving the vitamin D status of the population Page: 426
Vitamin E – α-tocopherol Page: 426
Key facts Page: 426
Overview Page: 427
Vitamin K – phylloquinone Page: 427
Key facts Page: 427
Overview Page: 428
Thiamin – vitamin B1 Page: 429
Key facts Page: 429
Nature and sources Page: 429
Functions Page: 429
Requirements and assessment of status Page: 430
Deficiency states Page: 430
Riboflavin – vitamin B2 Page: 431
Key facts Page: 431
Nature and sources Page: 432
Functions Page: 432
Requirements and assessments of status Page: 432
Riboflavin deficiency Page: 432
Niacin – vitamin B3 Page: 432
Key facts Page: 432
Nature and sources Page: 433
Functions Page: 434
Dietary requirements and assessment of status Page: 434
Niacin deficiency Page: 434
Vitamin B6 – pyridoxine Page: 435
Key facts Page: 435
Nature and sources Page: 435
Functions Page: 436
Requirements and assessment of status Page: 436
Deficiency and toxicity Page: 436
Vitamin B12 – cobalamins Page: 437
Key facts Page: 437
Nature and sources Page: 437
Functions Page: 438
Requirements and assessment of status Page: 438
Deficiency of B12 Page: 438
Folate or folic acid (vitamin B9) Page: 438
Key facts Page: 438
Nature and sources Page: 439
Functions Page: 440
Requirements and assessment of folate status Page: 440
Folate deficiency Page: 440
Folic acid and birth defects Page: 441
Potential hazards of high folic acid intake Page: 441
Biotin Page: 441
Key facts Page: 441
General overview Page: 441
Pantothenic acid Page: 442
Key facts Page: 442
Vitamin C – ascorbic acid Page: 442
Key facts Page: 442
Nature and sources Page: 443
Functions Page: 443
Requirements and assessment of status Page: 443
Deficiency states Page: 443
Benefits and risks of high intakes Page: 444
Key references Page: 446
16 The minerals Page: 446
Introduction Page: 447
Chromium Page: 448
Key facts Page: 448
Overview Page: 449
Copper Page: 449
Key facts Page: 449
Overview Page: 449
Fluoride Page: 450
Magnesium Page: 451
Key facts Page: 451
Overview Page: 451
Manganese Page: 451
Overview Page: 452
Molybdenum Page: 452
Key facts Page: 452
Overview Page: 452
Phosphorus Page: 452
Potassium Page: 453
Key facts Page: 453
Overview Page: 453
Selenium Page: 454
Key facts Page: 454
Overview Page: 454
Zinc Page: 455
Key facts Page: 455
Overview Page: 455
Iodine and iodine deficiency diseases Page: 457
Key facts Page: 457
Distribution and physiological function of body iodine Page: 457
Iodine deficiency Page: 457
Epidemiology of iodine deficiency across the world Page: 458
Iodine in the UK and other affluent countries Page: 459
High intakes and goitrogens in food Page: 460
Iron and iron deficiency anaemia Page: 461
Iron nutrition Page: 461
Key facts Page: 461
Distribution of body iron Page: 462
Requirement for dietary iron Page: 462
Regulation of iron balance and iron overload Page: 463
Determination of iron status Page: 463
Iron deficiency Page: 464
Prevalence of iron deficiency and anaemia Page: 464
Preventing iron deficiency Page: 465
Calcium, diet and osteoporosis Page: 467
Key facts Page: 467
Distribution and functions of body calcium Page: 467
Hormonal regulation of calcium homeostasis Page: 468
Requirement and availability of calcium Page: 468
Calcium and bone health Page: 470
The nature of bone Page: 470
Effects of age and sex upon bone density and fracture risk Page: 470
Incidence of osteoporosis Page: 472
General and lifestyle risk factors for osteoporosis Page: 472
Dietary risk factors for osteoporosis Page: 474
Prevention and treatment of osteoporosis Page: 474
Diet and lifestyle conclusions Page: 476
Salt and hypertension Page: 477
Key facts Page: 477
Overview Page: 477
Historical importance of salt Page: 477
The problems with salt Page: 478
Requirement for salt Page: 479
Amount and sources of dietary salt Page: 480
A review of the evidence for a salt–hypertension link Page: 482
Observational evidence Page: 482
Experimental studies Page: 484
Relationship between salt intake and morbidity and mortality Page: 485
Other factors involved in the aetiology of hypertension Page: 486
Conclusions Page: 487
Key references Page: 488
PART 4 VARIATION IN NUTRITIONAL REQUIREMENTS AND PRIORITIES Page: 490
17 Nutrition and the human lifecycle Page: 492
Introduction Page: 493
Nutritional aspects of pregnancy Page: 495
Pregnancy overview Page: 495
Effects of malnutrition in pregnancy Page: 495
The scale of increased nutritional needs in pregnancy Page: 495
RNI and RDA for pregnancy Page: 496
Pregnancy outcomes Page: 497
Estimating the extra nutritional needs of pregnancy Page: 498
Preconception Page: 498
Energy aspects of pregnancy Page: 499
Protein in pregnancy Page: 502
Minerals in pregnancy Page: 503
Calcium Page: 503
Iron Page: 504
Folic acid/folate and NTDs Page: 505
Other vitamins in pregnancy Page: 505
Alcohol and pregnancy Page: 506
Lactation Page: 506
Infancy Page: 507
Breastfeeding versus bottle-feeding Page: 507
Prevalence of breastfeeding Page: 508
Factors influencing choice of infant feeding method Page: 510
The benefits of breastfeeding Page: 513
Weaning Page: 517
When to wean? Page: 517
What are weaning foods? Page: 518
The priorities for weaning foods Page: 518
Childhood and adolescence Page: 520
Data from the rolling NDNS programme Page: 521
The elderly Page: 525
Demographic and social trends Page: 525
The effects of ageing Page: 527
Nutritional requirements of the elderly Page: 529
The diets and nutritional status of elderly people Page: 531
Energy and macronutrients Page: 531
Levels of overweight, obesity and other risk factors Page: 533
Diet and disease risk in the elderly Page: 535
Key references Page: 538
18 Nutrition as treatment Page: 540
Diet as a complete therapy Page: 541
Overview and general principles Page: 541
Food allergy (including coeliac disease) Page: 542
Immediate hypersensitivity reactions Page: 542
Coeliac disease (gluten-induced enteropathy) Page: 543
Phenylketonuria Page: 545
Diet as a specific component of therapy Page: 546
Diabetes mellitus Page: 546
Classification and aetiology Page: 546
Diagnosis Page: 547
Symptoms and long term complications Page: 547
Principles of management Page: 548
Can type-2 diabetes be reversed? Page: 549
Cystic fibrosis Page: 551
Chronic renal failure Page: 553
Malnutrition in hospital patients Page: 554
Overview Page: 554
Prevalence of hospital malnutrition Page: 555
Consequences of hospital malnutrition Page: 555
The traditional causes of hospital malnutrition Page: 557
Improving the nutritional care of hospital patients Page: 560
Aims of dietetic management of general hospital patients Page: 560
Aids to meeting nutritional needs Page: 560
Measures that could improve the nutritional status of hospital patients Page: 561
Impact of nutritional support Page: 562
The Malnutrition Universal Screening Tool Page: 563
NICE quality standards and guidelines Page: 563
Key references Page: 564
19 Some other groups and circumstances Page: 566
Vegetarianism Page: 567
Introduction Page: 567
Prevalence of vegetarianism Page: 568
The risks and benefits of vegetarian and vegan diets Page: 569
Adequacy of vegetarian diets Page: 569
Vegetarian diets and nutritional guidelines Page: 573
Racial minorities Page: 574
Introduction and overview Page: 574
The health and nutrition of particular minority groups Page: 575
Dietary comparison of ethnic groups in Britain Page: 577
Nutrition and physical activity Page: 580
Fitness Page: 580
Guidelines Page: 582
Current levels of physical activity and fitness Page: 582
Long-term health benefits of physical activity Page: 585
Introduction Page: 585
Diet as a means to improving physical performance Page: 587
Key references Page: 590
PART 5 FOOD SAFETY AND QUALITY Page: 592
20 The safety and quality of food Page: 594
Aims of the chapter Page: 595
Consumer protection Page: 595
Food law Page: 595
Food labelling Page: 597
Labelling in the UK Page: 597
Labels in the US Page: 598
An overview of health claims Page: 599
Food poisoning and the microbiological safety of food Page: 601
Introduction Page: 601
The causes of food-borne diseases Page: 602
The causative organisms Page: 602
How bacteria make us ill Page: 603
Circumstances that lead to food-borne illness Page: 603
Principles of safe food preparation Page: 606
Requirements for bacterial growth Page: 606
Some specific causes of food poisoning outbreaks Page: 607
Some practical guidelines to avoid food poisoning Page: 608
Minimise the risks of bacterial contamination of food Page: 608
Maximise killing of bacteria during home preparation of food Page: 609
Minimise the time that food is stored under conditions that permit bacterial multiplication Page: 609
A note about treatment of food-borne disease Page: 610
Pinpointing the cause of a food poisoning outbreak Page: 610
A review of some common food poisoning organisms and foodborne illnesses Page: 612
The Campylobacter Page: 612
Salmonella Page: 612
C. perfringens Page: 613
E. coli 0157 and the VTEC bacteria Page: 613
S. aureus Page: 613
B. cereus Page: 614
C. botulinum Page: 614
L. monocytogenes Page: 614
Bovine spongiform encephalopathy (BSE) Page: 615
Overview Page: 615
The nature of prion diseases Page: 616
The infective agent Page: 616
Causes of prion disease Page: 616
The cattle epidemic of BSE Page: 617
Time course of the epidemic Page: 617
What caused the cattle epidemic? Page: 617
Measures taken to limit vCJD and eliminate BSE Page: 617
The human vCJD epidemic Page: 618
The costs of this crisis Page: 619
Food processing Page: 620
Some general pros and cons of food processing Page: 620
Specific processing methods Page: 622
Canning Page: 622
Pasteurisation Page: 622
Ultra-high temperature treatment Page: 622
Cook chill processing Page: 622
Food irradiation Page: 623
The chemical safety of food Page: 625
Overview of chemical hazards in food Page: 625
Natural toxicants and contaminants Page: 625
Circumstances that may increase chemical hazard Page: 625
Some natural toxicants in “Western” diets Page: 626
Residues of agricultural chemicals Page: 627
Food additives Page: 629
Uses Page: 629
Some arguments against the use of food additives Page: 629
Some counter-arguments Page: 629
Food additive regulation Page: 630
Testing the safety of food additives Page: 631
Key references Page: 634
Index Page: 635