This chapter looks into what affects ageing throughout a person's life. It mentions that ageing is associated with a progressive decline in physiological functioning and can result in loss of independence and poorer quality of life. Dietary habits and nutritional status in older people are determined by numerous factors, such as physiological changes that occur during ageing and these may impact on nutritional status in later life. Ageing is associated with an increased risk of disability and disease which depends on socioeconomic inequalities such as differences in lifestyle. The chapter considers the changes in physiological function during ageing and the nutritional relevance of these changes.
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Ageing and older people
Elizabeth A. Williams
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Alcohol
A. Stewart Truswell
This chapter is about alcohol, which is the only substance that is both a drug affecting brain function and a nutrient. It begins by looking at the production of alcoholic beverages. Alcohol is produced by alcoholic fermentation of glucose; from the basic fermented beverages, alcohol becomes concentrated by the process of distillation. The chapter then considers the metabolism of alcohol and its effect on the brain. Pharmacologists classify ethanol as a central nervous system depressant, and it is in the same group as volatile anaesthetic agents. With increasing levels of blood alcohol, people pass through successive stages of alcohol intoxication. The chapter discusses the medical consequences of excess consumption of alcohol, examining coronary heart disease and alcoholism. It also investigates whether there is genetic liability to alcohol dependence.
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Alcohol metabolism: implications for nutrition and health
Vinood B. Patel and Victor R. Preedy
This chapter considers implications for nutrition and health in relation to alcohol metabolism. It shows how individuals will have a preference for consuming different types of alcoholic beverages, referencing some communities that forbid alcohol consumption on religious, cultural, or moral grounds. Acute and chronic consumption of alcohol may cause malnutrition or act as a toxin and induce pathological changes in a variety of organs and tissues. The chapter provides an overview into how alcohol damages virtually all organs in the body before detailing the principal nutritional deficiencies related to alcoholism. It looks into the causes associated with drinking in low socioeconomic status groups, and government policies to minimize alcohol consumption.
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Anthropometry
Barry Bogin and Laura Medialdea Marcos
This chapter explains that anthropometry is the scientific measurement and analysis of variation in the size and shape of the human body. Anthropometry can provide a relatively quick and inexpensive means for the assessment of nutritional status. Thus, anthropometric assessment most commonly involves the measurement of height, weight, fatness, and muscularity and may include the estimation of biological maturation. The chapter shows that dietary intake and nutritional balance are key determinants of human physical growth and development. It then considers how to minimize the inaccuracy of recordings before detailing the use of anthropometric references and standards to estimate levels of under-nutrition and over-nutrition.
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Assessment of Nutritional Status
A. Stewart Truswell
This chapter presents an assessment of nutritional status. Dietary intake estimation, described in the preceding chapter, cannot always prove that an individual or community is well nourished or poorly or overnourished. Food intake measurement—really, estimation—is ultimately subjective. It depends on the memory, cooperation, and honesty of individuals. Assessment of nutritional status is, by contrast, ultimately objective. A person's weight, height, and chemical concentration in blood or urine is measured by an outside observer and if a second and third observer repeats the measurement, they should obtain about the same result. The chapter then looks at the uses of nutritional assessment, before considering anthropometric assessment and the estimation of body composition.
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The B Vitamins
A. Stewart Truswell
This chapter discusses the B vitamins, including thiamin (vitamin B1), riboflavin, niacin, vitamin B6, biotin, pantothenic acid, folate, and vitamin B12. Thiamin as the diphosphate, thiamin pyrophosphate (TPP), is a co-enzyme for the major decarboxylation steps in carbohydrate metabolism. Riboflavin is part of two important coenzymes, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are oxidizing agents. Meanwhile, niacin plays a central role in metabolism: it functions as the first hydrogen receptor in the electron chain during oxidative phosphorylation in the mitochondria. Vitamin B6 also functions in practically all the reactions involved in amino acid metabolism. Most folates are in the reduced form, tetrahydrofolate (THF), which plays an essential role in 1-carbon transfers in the body.
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Biochemical assessment
Hilary J. Powers
This chapter provides an overview of biochemical assessment. Biochemical assessment forms part of a coordinated set of nutritional investigations that may also include dietary assessment, anthropometry, physiological tests, and clinical investigations. The design of the biochemical aspect of a nutritional assessment depends on there being an available and suitable sample of body fluid or tissue for analysis. The chapter looks into the necessary precautions to be taken during sample selection, storage, and analysis, before providing an outline of essential fieldwork and laboratory methodologies. It covers the correlation between status and nutritional adequacy by considering inter-relationships between the biochemical and other indices of nutritional status.
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Biomarkers
Nita G. Forouhi and Albert Koulman
This chapter assesses biomarkers: characteristics that are objectively measured, as an indicator of normal biological processes, pathogenic processes, or responses to an exposure or intervention. Within that definition, all objective measurements in nutrition research that are indicators of the diet or nutrition-related processes, such as the assessment of body mass index as an indicator of body size, can therefore be called biomarkers. The chapter focuses on a nutritional biomarker specifically to indicate any biological specimen that is an indicator of nutritional status with respect to intake or metabolism of dietary constituents. Nutritional biomarkers include biochemical methods that assess dietary intake or nutritional status based on exogenous intake, endogenous processes, or a combination of both. Though there are multiple uses for nutritional biomarkers, a chief reason for their utility is to serve as complementary objective information rather than as a replacement for subjective dietary information from self-report methods.
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Body size and composition
Mario Siervo
This chapter looks into the use of body composition information in nutrition by considering the key concepts of body size and composition. Nutrients in the diet are essential to provide the elements from which the human body is built, such as energy and cofactors. Body composition changes throughout life since the water content of the body decreases, and the content of protein and fat increases. The chapter then discusses the strength and limitations of measurement techniques, such as bioelectrical impedance, dual-energy X-ray absorptiometry, and air displacement plethysmography. It also covers the recent development in the assessment of body composition using multi-compartment models and novel diagnostic models.
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Cancers
Kathryn E. Bradbury, Aurora Perez-Cornago, and Tim J. Key
This chapter focuses on the pathophysiology of cancer before considering the incidence of cancer worldwide and in the UK. Cancer refers to a disease in which the normal control of cell division is lost so that an individual cell multiplies inappropriately to form a tumour that eventually spreads and causes death. Cancer can arise from the cells of different tissues and organs in the body, so there are many different types of cancer. The chapter shows that the causes of cancer in different parts of the body vary while referencing the impact of tobacco, alcohol, ionizing radiation and ultraviolet light on the body. It considers the epidemiological data linking diet with cancer.
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Carbohydrate metabolism
John M. Brameld, Tim Parr, and David A. Bender
This chapter tackles the function of carbohydrate metabolism. Carbohydrates are not essential nutrients since there is no absolute requirement for a dietary intake. However, a very low carbohydrate diet results in chronically increased production and plasma concentrations of the ketone bodies (ketosis) and the absence of glycogen stores since carbohydrate mainly provides metabolic fuel to all tissues. The chapter then explains the main role of dietary carbohydrates as a metabolic fuel, such as affecting satiety, insulin secretion, and glucose homeostasis. It then considers the pathways of carbohydrate metabolism and its regulation before considering the role of glycogen as a carbohydrate reserve.
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Carbohydrates
Andrew Reynolds and Jim Mann
This chapter discusses carbohydrates, which are the most important source of food energy in the world. The major sources of dietary carbohydrate worldwide are cereal grains (primarily rice, wheat, and maize), with refined sugar, root crops (potatoes, cassava, yams, sweet potatoes, and taro), pulses, vegetables, fruit, and milk products contributing less to overall energy intake. Carbohydrate-containing foods, with the exception of sugar, contribute important amounts of protein, vitamins, minerals, phytochemicals, sterols, and antioxidants to diet. The chapter then looks at the measurement of dietary carbohydrates; the digestion and absorption of carbohydrates; and carbohydrate metabolism. It also considers the relationship between carbohydrates and postprandial glycaemia, gut disorders, and non-communicable disease. Finally, the chapter examines energy values and recommended intakes of carbohydrates.
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Cardiovascular Diseases
Jim Mann and Rachael McLean
This chapter explores cardiovascular disease (CVD), which includes coronary heart disease (CHD), also referred to as coronary artery disease or ischaemic heart disease (IHD), cerebrovascular disease or stroke, and peripheral arterial disease. A similar pathological process underlies each of these three groups of conditions, which affect the heart, the brain, and peripheral arteries. Inappropriate nutrition has most consistently been linked with CHD, and the chapter deals with risk factors for the disease influenced by diet, and the evidence indicating that dietary modification has the potential to reduce clinical CHD. While there are fewer data directly linking nutritional factors to cerebrovascular disease, there are several shared risk factors, and raised blood pressure is a particularly important causal factor for most types of stroke. Thus, dietary advice is a pivotal component in reducing the risk of CHD and cerebrovascular disease and in the treatment of those with established diseases.
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Childhood and Adolescent Nutrition
Rachael Taylor and Anne-Louise Heath
This chapter discusses childhood and adolescent nutrition. Childhood and adolescence are periods of rapid growth, learning, and development. Nutritional needs are high and differ in many respects from those of adults. Ensuring adequate food intake remains the challenge for many of the world's children. In contrast, for most children in high income countries, making more appropriate food choices and developing and maintaining healthy eating habits is paramount. Dietary recommendations for children and adolescents are expressed in two very different, but complementary, formats: dietary guidelines and nutrient intake values. Ideally, each country should develop its own dietary guidelines to ensure that the food- and nutrient-related health concerns of the country are addressed in the context of customary dietary patterns. The chapter then looks at undernutrition, childhood obesity, and some special issues that predominantly relate to adolescents.
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Dental disease
Paula Moynihan
This chapter looks into the epidemiology of dental disease to highlight the importance of teeth in eating, speaking, and enhancing facial appearance. Despite being associated with a low mortality rate, dental diseases inflict considerable pain and anxiety and are costly to healthcare services. Dental diseases include enamel developmental defects, tooth wear, periodontal disease, and dental caries. The chapter explains the role of dietary sugars and fluoride in the causation and prevention of decay while referencing the relative cariogenicity of various sugars and other carbohydrates. It also details the interaction between the protective effects of fluoride and the destructive effects of sugars.
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Diabetes and the Metabolic Syndrome
Jim Mann
This chapter focuses on diabetes and metabolic syndrome. Diabetes rates have increased in recent years and in many countries worldwide are considered to have reached epidemic proportions. Type 2 diabetes (T2DM) accounts for the majority of cases. While genetic factors determine susceptibility, the rapidly escalating rates are largely explained by the almost worldwide increase in obesity. Adherence to dietary advice similar to that recommended for treatment of diabetes substantially reduces the chances of those with prediabetes progressing to diabetes. Appreciable weight loss has the potential to enable the withdrawal of all drug treatment and induce remission of the condition in some with established disease. Meanwhile, the reasons for the increase in rates of type 1 diabetes (T1DM) in some countries is uncertain but nutrition therapy is necessary to ensure an appropriate balance between insulin and dietary carbohydrate and a nutrient profile expected to reduce risk of diabetes complications.
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Diabetes mellitus
Lutgarda Bozzetto, Brunella Capaldo, and Angela A. Rivellese
This chapter examines the aetiology and pathophysiology of diabetes mellitus. It defines diabetes mellitus as a metabolic disorder of multiple aetiology characterized by chronic hyperglycaemia associated with impaired carbohydrate, fat, and protein metabolism. Moreover, diabetes has been classified into four distinct types: type 1 diabetes, type 2 diabetes, gestational diabetes mellitus, and other specific types. The chapter presents the correlation between diabetes and obesity before demonstrating how to reduce insulin resistance through lifestyle modification. It elaborates on how to prevent long-term complications of diabetes by understanding the nutritional implications of insulin therapy and the multifactorial treatment of the major cardiovascular risk factors.
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Diet and epigenetics
John C. Mathers
This chapter explores the correlation between diet and epigenetics. It explains that epigenetics is the area of science concerned with heritable changes in gene expression which do not involve changes to the underlying DNA sequence. As the chapter explains, changes in epigenetic marks occur during embryogenesis and across the lifecourse in humans. The chapter elaborates on the marks and molecules which constitute the epigenetic machinery used to regulate gene expression. It also explains how dietary and other factors influence epigenetic patterns and relate to phenotype while discussing the effects of nutritional status, dietary patterns, and specific dietary factors on epigenetic marks and molecules in humans.
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Dietary Assessment
Jim Mann and Silke Morrison
This chapter evaluates dietary assessment, which is one of the specialized interests of nutritionists, used in surveillance of populations, nutritional epidemiology, clinical assessment, and experimental research. There are two basic approaches to estimating food intake: one principally concerned with determining the intake of populations, the other with assessing the diets of individuals. The chapter describes the various methods used in the different contexts in which knowledge of food and nutrient intakes are required. It looks at the reliability of the various methods, considering the conflict between the need for accuracy to establish exactly where an individual lies within the overall distribution of foods and nutrients and the logistics of doing so when very large populations required for epidemiological studies are investigated. Ultimately, true estimates of food consumption can only be obtained by observing the activities of participants, or by developing some other independent way of assessing food intake.
Chapter
Dietary assessment
Bridget Holmes
This chapter examines the purpose of dietary assessment. Dietary assessment involves the collection of information on the quantity and frequency of foods and drinks consumed over a specified time, and using food composition tables. The level of assessment and method must be selected with careful consideration by taking into account the exact purpose of the assessment. All dietary assessments aim to measure food consumption or to estimate the intake of nutrients or non-nutrients in individuals or groups for various reasons, such as the estimation of total food quantity for consumption of an entire country. The chapter notes the important factors in dietary assessment, such as portion assessment, use of technology, food composition tables, and assessment in special populations.
