There is a growing database that has evaluated the effects of varying amounts of total fat on risk factors for cardiovascular disease, diabetes and overweight and obesity. The evidence clearly suggests that extremes in dietary fat should be avoided, and instead a diet moderate in total fat (25–35 % energy) is preferable for the majority of individuals. Moreover, we now appreciate the importance of individualizing dietary fat recommendations within this range of total fat. With respect to cardiovascular disease, a diet higher in total fat (30–35 % energy) affects the lipid and lipoprotein risk profile more favourably than a lower-fat diet; this is also the case for individuals with diabetes, with the added benefit of better glycaemic control. Dietary fibre (≧25g/d) attenuates and even prevents the potentially adverse lipid and lipoprotein effects of a lower-fat diet. With respect to weight control, a moderate-fat diet can be as, or even more, effective than a lower-fat diet, because of advantages with long-term adherence and potentially favourable effects on lipids and lipoproteins. Thus, there is now a convincing scientific basis to advocate a diet moderate in total fat for the majority of individuals. Implicit to this position is that unsaturated fat has numerous beneficial health effects. However, because fat is energy dense, moderation in fat intake is essential for weight control. Consequently, a simple message to convey is to avoid diets that are very low and very high in fat. Moreover, within the range of a moderate-fat diet it is still important to individualize the total fat prescription. Nonetheless, the guiding principle is that moderation in total fat is the defining benchmark for a contemporary diet that reduces risk of chronic disease.

Glucose intolerance represents a spectrum of abnormalities, including impaired fasting glucose, impaired glucose tolerance and type 2 diabetes. It is a major public health challenge worldwide, with rapidly increasing prevalence rates in both developed and developing countries. This global epidemic of diabetes is largely driven by the globalisation of Western culture and lifestyles. Specifically, there is now evidence from large-scale observational studies, and from intervention studies, of powerful synergistic interactions between diet, obesity, exercise, smoking and alcohol in the development of glucose intolerance. It is estimated that > 90 % of cases of type 2 diabetes in the population could be prevented with the adoption of a prudent diet (high in cereal fibre and polyunsaturated fatty acids and low in trans-fatty acids and glycaemic load), avoidance of overweight and obesity (BMI < 25 kg/m2), engagement in moderate to vigorous physical activity for at least 05 h/d, non-smoking and moderate alcohol consumption. These findings are biologically plausible and have major public health implications. They form the basis for a clear, simple and coherent message for health promotion and public policy. However, to make progress on these issues health will need to be placed at the centre of public policy and relevant vested interests tackled, notably in the food, entertainment, tobacco and automobile industries.

The role of high-fat diets in weight gain and obesity is assessed by evidence-based principles. Four meta-analyses of weight change occurring on ad libitum low-fat diets in intervention trials consistently demonstrate a highly significant weight loss of 3–4 kg in normal-weight and overweight subjects (P< 0·001). The analyses also find a dose-response relationship, i.e. the reduction in percentage energy as fat is positively associated with weight loss. Weight loss is also positively related to initial weight; a 10 % reduction in dietary fat is predicted to produce a 4–5 kg weight loss in an individual with a BMI of 30kg/m2. The non-fat macronutrient composition of the diet is also important. Whereas the glycaemic index of the carbohydrate may play a role for cardiovascular risk factors, there is so far no evidence that low-glycaemic index foods facilitate weight control. In contrast, intervention studies show that sugar in drinks is more likely to produce weight gain than solid sugar in foods. Although the evidence is weak, alcoholic beverages promote a positive energy balance, and wine may be more obesity-promoting than beer. Protein is more satiating and fhermogenic than carbohydrates, and one intervention study has shown that an ad libitum low-fat diet where carbohydrate was replaced by protein produced more weight loss after 6 months (8·1 v. 5·9 kg). The evidence linking particular fatty acids to body fatness is weak. If anything, monounsaturated fat may be more fattening than polyunsaturated and saturated fats, and no ad libitum dietary intervention study has shown that a normal-fat high-monounsaturated fatty acid diet is equivalent or superior to a low-fat diet in the prevention of weight gain and obesity. The evidence strongly supports the low-fat diet as the optimal choice for the prevention of weight gain and obesity, while the use of a normal-fat high-monounsaturated fatty acid diet is unsubstantiated.

Chronic infection with HIV type 1 is associated with alterations in macronutrient metabolism, specifically elevated plasma lipids, glucose and reduced insulin sensitivity. These alterations are most severe in patients at the later stages of AIDS, indicating a relationship with disease progression. Recently, a metabolic syndrome, termed lipodystrophy, has been described in successfully-treated HIV patients in whom the altered macronutrient metabolism of HIV infection appears to be amplified markedly, with concurrent alterations in adipose tissue patterning. This syndrome presents a paradox, as before the development of highly-active antiretroviral therapy (HAART) the most severe perturbations in metabolism were observed in the sickest patients. Now, the patients that respond well to therapy are showing metabolic perturbations much greater than those seen before. The implications of this syndrome are that, whilst life expectancy may be increased by reducing viral load, there are concomitant increases in the risk of cardiovascular disease, diabetes and pancreatitis within this patient population. The aetiology of the syndrome remains unclear. In a collaborative trial with the Chelsea and Westminster Hospital in London we have used stable-isotope-labelled fatty acids to examine the hypothesis that treatment with HAART causes a delayed clearance of dietary lipid from the circulation, resulting in the retention of lipid within plasma and the downstream changes in insulin and glucose homeostasis. This hypothesis would indicate a role for low-fat diets, exercise and drugs that reduce plasma lipid or insulin resistance, in modulating the response to antiretroviral therapy in HIV infection.

Socially-and culturally-patterned differences in food habits exist both between and within European populations. Daily individual food availability data, collected through the national household budget surveys (HBS) and harmonized in the context of the Data Food Networking (DAFNE) project, were used to assess disparities in food habits of seven European populations and to evaluate dietary changes within a 10-year interval. The availability of selected food items was further estimated according to the educational level of the household head and, based only on the Greek HBS data, according to quintiles of the household's food purchasing capacity. Results for overall food availability support the north-south differentiation in food habits. Generally, the availability of most food items, including foods such as vegetable fats, animal lipids and sugar products, has decreased over the 10 years. Households in which the head was in the higher education categories reported lower availability for most food items, with the exception of low-fat milk, fresh fruit, animal lipids and soft drinks; the latter showing a sharp increase even within southern European households. The household's food purchasing capacity can be used as an indicator of socio-economic status, with higher values being associated with lower status. Greek households of lower social class follow a healthier diet in terms of greater availability of vegetable oils, fresh vegetables, legumes, fish and seafood. Data from the DAFNE databank may serve as a tool for identifying and quantifying variation in food habits in Europe, as well as for providing information on the socio-economic determinants of food preferences.

Periodontal disease is a common chronic adult condition. The bacterium Porphyromonas gingivalis has been implicated in the aetiology of this disease, which causes destruction of the connective tissue and bone around the root area of the tooth. It has been observed that invading P. gingivalis bacteria trigger the release of cytokines such as interleukin 8 and tumour necrosis factor α, leading to elevated numbers and activity of polymorphonucleocytes (PMN). As a result of stimulation by bacterial antigens, PMN produce the reactive oxygen species (ROS) superoxide via the respiratory burst as part of the host response to infection. Patients with periodontal disease display increased PMN number and activity. It has been suggested that this proliferation results in a high degree of ROS release, culminating in heightened oxidative damage to gingival tissue, periodontal ligament and alveolar bone. Antioxidant constituents in plasma have been well-documented, being chiefly ascorbate, albumin and urate, and these are known to display sensitivity to dietary antioxidant intakes. The concentration of antioxidants in saliva does not appear to mirror those of plasma. The extent of dietary influence upon salivary antioxidant status is unclear. Urate is the predominant salivary antioxidant, with albumin and ascorbate providing minor contributions. Previous research has found reduced salivary antioxidant activity in patients suffering from periodontal disease. An improved understanding of the role antioxidants play in periodontitis, and the influence of nutrition on antioxidant status, may lead to a possible nutritional strategy for the treatment of periodontal disease.

Development of effective intervention strategies to meet the needs of people with ethnic minority origins is dependent on two factors: an understanding of the modifiable risk factors which can form the basis of intervention; an understanding of the relevant health behaviours so that appropriate strategies can be designed. The present paper briefly reviews the evidence concerning the part that nutritional and dietary factors play in the aetiology of the observed patterns of disease in these groups and the limitations of the data as a basis for intervention. Consideration is also given to the available information concerning factors influencing health behaviour (particularly eating behaviour) and the applicability of commonly-used models of behaviour change to people of ethnic minority origin. Finally, the results of nutrition intervention programmes will be examined with a view to identifying lessons for the future.

As a result of the increasing consumer demand for minimally-processed fresh-like food products with high sensory and nutritional qualities, there is a growing interest in non-thermal processes for food processing and preservation. Key advanced technologies such as high-pressure processing, pulsed electric fields, dense gases and ultrasound are being applied to develop gentle but targeted processes to further improve the quality and safety of processed foods. These technologies also offer the potential for improving existing processes as well as for developing new process options. Furthermore, by adding new process dimensions (such as hydrostatic pressure, electric fields, ultrasonics, supercritical CO2) to the conventional process variables of temperature and time, they facilitate enlargement of the availability of unit operations. These operations might be applied effectively in unique combination processes, or as subsequent processing tools in more-targeted and subsequently less-intensive processes for food preservation and modification than the currently-applied processes.

Developments in food technology and nutrition today are shaping our food supply in an unprecedented way. They have not only helped produce a variety of foods with varying taste and texture but also optimally retain the nutritional quality of food. Increased use of novel ingredients in the future manufacture of foods is likely to reduce the amount of micronutrients available in our diet. To combat this, food fortification may be more widely used. Collaboration between food technologists and nutritionists is imperative if we are to see the continued manufacture of wholesome food.

Budget standards are specified baskets of goods and services which, when priced, can represent predefined living standards. ‘Low cost but acceptable’ (LCA) is a minimum income standard, adequate to provide warmth and shelter, a healthy and palatable diet, social necessities, social integration, avoidance of chronic stress and the maintenance of good health (physical, mental and social) in a context of free access to good-quality health care, good-quality education and social justice. The LCA food budget standard identifies a basket of foods and corresponding menus which provides (for a given household composition) a palatable diet that is consistent with prevailing cultural norms, and that satisfies existing criteria for health in relation to dietary reference values, food-based dietary guidelines and safe levels of alcohol consumption. Two previous studies that explored the relationship between diet and food expenditure in low-income households suggested that the amount spent on food was a good predictor of dietary adequacy, growth and health in children. The current paper will focus on diet and measures of deprivation in 250 low-income households in London. Households were screened for material deprivation (e.g. no car, no fixed line telephone, in receipt of Income Support) using a doorstep questionnaire. Diet was assessed using four 24 h recalls based on the ‘triple pass’ method. Expenditure on food and other aspects of household circumstances were assessed by face-to-face interview. Food expenditure in these households was characterized in relation to food budget standards. Further analyses explored the relationships between food expenditure and dietary adequacy, growth in children and measures of deprivation.

Role of substrate utilization and thermogenesis on body-weight control with particular reference to alcohol By Yves Schutz Volume 59 (2000), Number 4 Figure 1, page 513

Food policies deliver large quantities of food relatively safely, but they are failing to deliver healthy diets. Policies fall into three broad categories: the supply of sufficient amounts of food (food security); the provision of food free from contamination (food safety); the provision of a healthy diet available to all (nutritional quality). These three aspects are dealt with by institutions that rarely engage with each other, let alone coordinate their strategies. Greater financial support has been given to agricultural policy than to any other joint EU endeavour. In the last decade food safety has dominated headlines and has influenced recent changes to EU food policies. New food authorities and agencies have been established and ministerial responsibilities have been redefined. Yet, it is nutrition, or rather `mis-nutrition', that is the largest single cause of death and disease within the region, and indeed worldwide. This need not be the case. Nutrition and dietary policies may find themselves in close alliance with policies for sustainable agriculture. However, the change in thinking that will be required will mean reconsidering the role of commercial food production. Successful nutrition policies may yet prove to be the next major step in the improvement of public health.