Feed formulation to meet nutritional requirements of livestock is becoming increasingly challenging. Regulations have banned the use of traditional high-quality protein supplements such as meat-and-bone meal, pollution from animal excreta of N and P is an issue and antibiotics are no longer available as insurance against the impact of enteric infection and feed anti-nutritional factors. The improved genetic potential of livestock is increasing daily requirement for energy and protein (essential amino acids). To benefit from the enhanced growth potential of livestock diets with high nutrient density are needed that can be formulated from crops without increased cost. Genetic modification of commodity crops used to manufacture animal feed in order to improve the density and quality of available nutrients is a potential solution to some of these problems. Furthermore, crops may be used as biofactories to produce molecules and products used in animal feed with considerable reductions in manufacturing fixed costs. Nevertheless, there are considerable not insurmountable challenges, such as the creation of sufficient economic value to deliver benefit to all members in the feed production chain, which is an essential element of identity preserving and delivering the technology to livestock producers. Individual output traits in the major commodity crops may not provide sufficient value to adequately compensate all the members of the feed production chain. Successful adoption of output traits may rely on inserting combinations of agronomic input traits with specific quality traits or increasing the value proposition by inserting combinations of output traits.

Growth failure and poor nutritional status are features of children with chronic disease. Oral protein–energy supplements are one of a number of interventions provided with the aim of improving nutritional status in these children. The present paper describes a Cochrane systematic review assessing the efficacy of these products in children with chronic disease. The objective was to examine the evidence that in children with chronic disease oral protein–energy supplements alter nutrient intake, nutritional indices, survival and quality of life. All randomised controlled trials of the use of oral protein–energy supplements in children with chronic disease were identified through searching electronic databases and hand searching the abstract books of nutrition conferences. Studies identified were independently assessed for eligibility and methodological quality, and data on outcomes of interest were combined in a meta-analysis where possible. Two trials were eligible for inclusion in the review, both of which were undertaken with children with cystic fibrosis. No statistical differences could be found between treatment and control groups when data from both studies were combined. Oral protein–energy supplements are widely used to improve the nutritional status of children with chronic disease. No conclusions can be drawn on the efficacy of these products based on the limited data available. Further randomised controlled trials are required to investigate the use of these products in children with chronic disease. Until further data are available, these products should be used with caution.

Cancer is the major cause of death in the UK, and the Government has set a target to reduce death rate from cancer in individuals 75 years by ≥20% by 2010. Whilst earlier diagnosis and more effective treatments will contribute to meeting this target, there are considerable opportunities to prevent cancer by improving diet and other aspects of lifestyle. There is now a good understanding of the biological basis of carcinogenesis, which is providing the basis for mechanistic investigation of the chemo-preventive properties of certain foods and food components. It is becoming increasingly clear that there are important interactions between an individual's genotype (characterised by single nucleotide polymorphisms in particular genes) and habitual diet that modulate the risk of developing cancer. The technology to support this post-genomic revolution in nutrition research is now widely available, but brings with it considerable challenges in terms of study design and ethics. However, in the absence of a robust body of evidence on which dietary strategies will benefit which individuals, soundly based genetically-targeted nutrition advice to the public on cancer prevention is a little way in the future.

Diverticulosis is a condition that is associated with ageing. The older the individual the more likely they are to have diverticulosis, but this process is not necessarily inevitable. Diverticula are a herniation through the wall of the sigmoid colon and are likely to be a consequence of a weakness in the colonic wall or prolonged exposure to increased intracolonic pressure consequent on a low dietary fibre intake. The tensile strength of the colon declines with age and becomes least in the distal colon. Adult Africans living in Africa eat a high-fibre diet and are free from diverticulosis. Their colons are stronger, wider and thinner than those Scottish adults of the same age. The strength of the colon is in part dependent on collagen fibres and their diameter. The collagen fibrils on the left side of the colon are smaller and more tightly packed than those of the right side of the colon. Ageing and the presence of colonic diverticulosis are associated with smaller more-tightly-packed collagen fibrils. An animal model was established to investigate the effect of a lifelong high- and low-fibre diet on the development of colonic diverticulosis. The findings show that a high-fibre diet from birth, and preferably a maternal high-fibre diet, lessen the risk of diverticulosis with age.

Malnutrition has long been recognised as a risk factor for post-operative morbidity and mortality. Traditional metabolic and nutritional care of patients undergoing major elective surgery has emphasised pre-operative fasting and re-introduction of oral nutrition 3–5 d after surgery. Attempts to attenuate the consequent nutritional deficit and to influence post-operative morbidity and mortality have included parenteral, enteral and oral sip feeding. Recent studies have emphasised that an enhanced rate of recovery can be achieved by a multi-modal approach focused on modulating the metabolic status of the patient before (e.g. carbohydrate and fluid loading), during (e.g. epidural anaesthesia) and after (e.g. early oral feeding) surgery. Using such an approach preliminary results on patients undergoing elective colo-rectal surgery indicate a significant reduction in hospital stay (traditional care, n 48, median stay 10 d v. enhanced recovery programme, n 33, median stay 7d; P<0·01) can be achieved. Such findings emphasise the potential role of multi-modal care programmes in the promotion of early recovery from major surgical trauma.

Interventions for prevention and treatment of childhood obesity typically target increases in physical activity and, more recently, reductions in physical inactivity (sedentary behaviour such as television viewing). However, the evidence base for such strategies is extremely limited. The main aim of the present review was to update the systematic review and critical appraisal of evidence in the light of the recent rapid expansion of research in this area. Randomised controlled trials (RCT) that targeted activity or inactivity, that followed up children or adolescents for at least 1 year and that included an objective weight-related outcome measure were included. Trials were appraised using previously published criteria (Harbour & Miller, 2001), and literature search strategies described previously (Reilly et al. 2002) were updated to May 2002. A total of four new RCT, two new systematic reviews and one meta-analysis were identified. The evidence base has increased markedly since the completion of earlier reviews, although high-quality evidence is still lacking. The evidence on childhood obesity prevention is not encouraging, although promising targets for prevention are now clear, notably reduction in sedentary behaviour. There is stronger evidence that targeting activity and/or inactivity might be effective in paediatric obesity treatment, but doubts as to the generalisability of existing interventions, and the clinical relevance of the interventions is unclear. Further research in settings outside the USA is urgently needed, and two ongoing RCT in Scotland are summarised.

Establishing a definition for dietary fibre has historically been a balance between nutrition knowledge and analytical method capabilities. While the most widely accepted physiologically-based definitions have generally been accurate in defining the dietary fibre in foods, scientists and regulators have tended, in practice, to rely on analytical procedures as the definitional basis in fact. As a result, incongruities between theory and practice have resulted in confusion regarding the components that make up dietary fibre. In November 1998 the president of the American Association of Cereal Chemists (AACC) appointed an expert scientific review committee and charged it with the task of reviewing and, if necessary, updating the definition of dietary fibre. The committee was further charged with assessing the state of analytical methodology and making recommendations relevant to the updated definition. After due deliberation, an updated definition of dietary fibre was delivered to the AACC Board of Directors for consideration and adoption (Anon, 2000; Jones 2000/7). The updated definition includes the same food components as the historical working definition used for approximately 30 years (a very important point, considering that the majority of the research of the past 30 years delineating the positive health effects of dietary fibre is based on that working definition). However, the updated definition more clearly delineates the make-up of dietary fibre and its physiological functionality. As a result, relatively few changes will be necessary in analytical methodology. Current methodologies, in particular AACC-approved method of analysis 32–05 (Grami, 2000), Association of Official Analytical Chemists' official method of analysis 985.29 (Horwitz, 2000a) or AACC 32–07 (Grami, 2000) Association of Official Analytical Chemists 991.43 (Horwitz, 2000a) will continue to be sufficient and used for most foods. A small number of additional methods will be necessary to quantify the dietary fibre levels in foods containing fibres such as fructans (polymers and oligomers of fructose, inulin), modified dextrins, and/or synthetic dietary fibre analogues.

The urgency generated by drug-resistant strains of malaria has accelerated anti-malarial drug research over the last two decades. While synthetic pharmaceutical agents continue to dominate research, attention increasingly has been directed to natural products. The present paper explores the larger context in which plant use occurs and considers how the selection of medicinal plants has evolved over millennia as part of the larger human effort to mediate illness. First attention is directed to indigenous medicinal plants whose anti-malarial activity is based on an oxidant mode of action, by which intracellular constituents lose electrons (become more electropositive). Next, parallels are drawn between these plant substances and a suite of malaria-protective genetic traits: glucose-6-phosphate dehydrogenase deficiency; haemoglobins S, C and E; α- and β-thalassemias. These erythrocyte anomalies are classic examples of Darwinian evolution, occurring in high frequency in populations who have experienced considerable selective pressure from malaria. Characterized by discrete loci and pathophysiologies, they are united through the phenomenon of increased erythrocyte oxidation. In this model, then, oxidant anti-malarial plants are culturally constructed analogues, and molecular mimics, of these genetic adaptations. To further reinforce the scheme, it is noted that the anti-malarial action of pharmaceutical agents such as chloroquine and mefloquine duplicates both the genetic anomalies and the folk therapeutic models based in oxidant plants. This discussion coheres around a theoretical foundation that relates plant secondary metabolites (oxidants) to plasmodial biochemistry and human biological and cultural adaptations to malaria. Co-evolution provides a theoretical link that illuminates how medical cultures manage the relationships among humans, plants, herbivores and their respective pathogens.

Conjugated linoleic acids (CLA) have been shown to have anti-carcinogenic, anti-obesity, anti-atherogenic and immunomodulatory functions. The basis for these effects has not been fully explained, but probably involves effects of CLA on eicosanoid metabolism, cytokine production and\or gene expression. The predominant isomer (85–90%) in the natural sources of CLA has the cis-9, trans-11 configuration. As interest in CLA grew and synthetic forms became available, the number of studies examining the effects of dietary CLA in rodents, human subjects and livestock has increased greatly. In the late 1990 s the observation that CLA had anti-obesity effects was reported. Subsequently, it was determined that this effect in mice could be attributed to the trans-10, cw-12 isomer that, along with the cis-9,trans-11 isomer, predominates in the synthetic forms of CLA. The santi-obesity response varies in magnitude depending on species, and has not been consistent in non-rodents. In general, the response is greatest in mice and less or absent in other species. The basis for this lack of consistency is not clear and is unlikely to be accounted for by differences in the source of CLA. In the pig variation in body fat of animals may account for differences in responsiveness. There is no direct evidence of an anti-carcinogenic effect of CLA in human subjects or livestock. Indirect evidence from in vitro studies with cell lines, as well as epidemiological studies, suggest that CLA may be relevant as a natural anti-carcinogen. The immunomodulatory effects of CLA may have application in livestock production as an alternative to the use of feed antibiotics, or as a means of improving the response to vaccination and conferring disease resistance. The recent literature on the effects of CLA, with emphasis on its anti-obesity effects, is reviewed.

Vitamin D is produced endogenously when the skin is exposed to sunlight and can be obtained exogenously from a few natural food sources, from food fortification and from supplements. Generally, vitamin D intake is low ≤2–3 μg/d in Europe. Casual exposure to sunlight is thought to provide most of the vitamin D requirement of the human population. However, skin synthesis of vitamin D may not compensate for the low nutritional intake in Europe, even in countries with high supplies from food fortification and supplements. For assessment of vitamin D nutritional status the concentration of 25-hydroxyvitamin D (25(OH)D) in serum is considered to be an accurate integrative measure reflecting an individual's dietary intake and cutaneous production. A substantial percentage of the elderly and adolescents in Europe have a low concentration of 25(OH)D; in the elderly this percentage ranges from approximately 10 in the Nordic countries to approximately 40 in France. Low vitamin D status seems to be aggravated by disease and immobility, and by a low frequency of supplement use.

The relationship between frequency of consumption of whole-grain foods and cancer risk has been analysed using data from an updated series of case-control studies conducted in Northern Italy between 1983 and 1997. The overall dataset included the following incident histologically-confirmed neoplasms: oral cavity and pharynx 524, oesophagus 410, stomach 745, colon 955, rectum 625, liver 435, gallbladder 65, pancreas 402, larynx 388, soft tissue sarcomas 217, breast 3412, endometrium 750, ovary 971, prostate 127, bladder 431, kidney 190, thyroid 428, Hodgkin's disease 201, non-Hodgkin's lymphomas 529, multiple myelomas 185. Controls were 10 058 patients admitted to hospital for acute non-neoplastic conditions unrelated to long-term modifications in diet, tobacco or alcohol use. The multivariate odds ratios for the highest category of whole-grain cereal consumption were 0.3–0.5 for upper digestive tract and respiratory neoplasms and colon, 0.6 for rectum and liver, 0.4 for gallbladder, 0.8 for pancreas, 0.2 for soft tissue sarcomas, 0.9 for breast and endometrium, 0.7 for ovary, 0.7 for prostate, 0.4 for bladder and kidney, 1.1 for thyroid and about 0.5 for lymphomas and 0.6 for myelomas. In this population whole-grain food consumption is an indicator of reduced risk of several neoplasms.

The direct effects of physical activity interventions on energy expenditure are relatively small when placed in the context of total daily energy demands. Hence, the suggestion has been made that exercise produces energetic benefits in other components of the daily energy budget, thus generating a net effect on energy balance much greater than the direct energy cost of the exercise alone. Resting metabolic rate (RMR) is the largest component of the daily energy budget in most human societies and, therefore, any increases in RMR in response to exercise interventions are potentially of great importance. Animal studies have generally shown that single exercise events and longer-term training produce increases in RMR. This effect is observed in longer-term interventions despite parallel decreases in body mass and fat mass. Flight is an exception, as both single flights and long-term flight training induce reductions in RMR. Studies in animals that measure the effect of voluntary exercise regimens on RMR are less commonly performed and do not show the same response as that to forced exercise. In particular, they indicate that exercise does not induce elevations in RMR. Many studies of human subjects indicate a short-term elevation in RMR in response to single exercise events (generally termed the excess post-exercise O2 consumption; EPOC). This EPOC appears to have two phases, one lasting 2 h and a smaller much more prolonged effect lasting up to 48 h. Many studies have shown that long-term training increases RMR, but many other studies have failed to find such effects. Data concerning long-term effects of training are potentially confounded by some studies not leaving sufficient time after the last exercise bout for the termination of the long-term EPOC. Long-term effects of training include increases in RMR due to increases in lean muscle mass. Extreme interventions, however, may induce reductions in RMR, in spite of the increased lean tissue mass, similar to the changes observed in animals in response to flight.

Physical activity influences energy metabolism in human subjects by increasing activity-induced energy expenditure and resting metabolic rate for several hours after exercise. On the other hand, physical activity increases mechanical energy efficiency, suggesting that trained subjects would need less energy for daily activities. The underlying mechanism by which physical activity influences energy metabolism is largely unknown. The skeletal muscle-specific homologue of uncoupling protein (UCP) 1, UCP3, could possibly play a major role in energy expenditure. UCP3 is, like UCP1, able to uncouple respiration from ATP production. A strong link or association between the UCP3 gene and energy metabolism was found. Furthermore, UCP3 mRNA expression is related to sleeping metabolic rate, and thyroid hormone, a powerful stimulator of energy expenditure, up regulates UCP3. Finally, mice overexpressing UCP3 are hyperphagic but lean. These findings indicated that UCP3 is related to energy metabolism and that UCP3 could have a role in the effect of physical activity on energy expenditure. Thus, acute exercise up regulates UCP3, whereas endurance training results in the down-regulation of UCP3 protein content. Only a minimal amount of physical activity is needed for down-regulation of UCP3. Moreover, there is very strong evidence that UCP3 is negatively related to mechanical energy efficiency, suggesting that the down-regulation of UCP3 with training increases mechanical energy efficiency. Taken together, although the exact function of UCP3 is still unknown, exercise and training studies clearly show that under certain circumstances UCP3 is strongly related to human energy metabolism, possibly as a secondary effect of its (yet) unknown primary function.

Prolonged vitamin D deficiency resulting in rickets is seen mainly during rapid growth. A distinct age distribution has been observed in the Copenhagen area where all registered hospital cases of rickets were either infants and toddlers or adolescents from immigrant families. Growth retardation was only present in the infant and toddler group. A state of deficiency occurs months before rickets is obvious on physical examination. Growth failure, lethargy and irritability may be early signs of vitamin D deficiency. Mothers with low vitamin D status give birth to children with low vitamin D status and increased risk of rickets. Reports showing increasing rates of rickets due to insufficient sunlight exposure and inadequate vitamin D intake are cause for serious concern. Many countries (including the USA from 2003) recommend vitamin D supplementation during infancy to avoid rickets resulting from the low vitamin D content of human milk. Without fortification only certain foods such as fatty fish contain more than low amounts of vitamin D, and many children will depend entirely on sun exposure to obtain sufficient vitamin D. The skin has a high capacity to synthesize vitamin D, but if sun exposure is low vitamin D production is insufficient, especially in dark-skinned infants. The use of serum 25-hydroxyvitamin D to evaluate vitamin D status before development of rickets would be helpful; however, there is no agreement on cut-off levels for deficiency and insufficiency. Furthermore, it is not known how marginal vitamin D insufficiency affects children's bones in the long term.

The declining consumption of ruminant products has been partly associated with their high proportion (but not necessarily content) of saturated fatty acids. Recent studies have focused on the less prominent fact that they are also important sources of beneficial fatty acids, including n-3 fatty acids and conjugated linoleic acids. α-Linolenic acid (18: 3n-3) is of particular interest because it also contributes to improved flavour of beef and lamb. Many recent studies showed large effects of special concentrates on levels of fatty acids in milk and meat. However, the ‘rumen protection’ treatments, needed to ensure a worthwhile level of fatty acid in products, are expensive. Herbage lipids are the cheapest and safest source of these fatty acids and so breeding to increase delivery of fatty acids from plants into ruminant products is an important long-term strategy. Plant lipids usually contain high levels of polyunsaturated fatty acids, particularly 18: 2n-6 and 18:3n-3 which are the precursors of beneficial fatty acids. Whilst some plants are particularly rich in individual fatty acids (e.g. 18:3n-3 in linseed), there are also useful levels in grass and clover (Trifolium Spp.). Levels of fatty acids in forages in relation to species and varieties are considered, as well as management and conservation methods. Relationships between levels of fatty acids and existing traits and genetic markers are identified. The effects of forage treatments on the fatty acid content of ruminant products are reviewed. The higher levels of polyunsaturated fatty acids in milk from cows fed clover silages show that the level of fatty acids in herbage is not the only factor affecting levels of fatty acids in ruminant products. Further effort is needed to characterise susceptibility of unsaturated fatty acids to oxidative loss during field wilting and biohydrogenation losses in the rumen, and the relative importance of plant and microbial processes in these losses. The pathways of lipolysis and lipid oxidation are reviewed and other plant factors which offer potential to breed for reduced losses are considered.

Loss of function of the adenomatous polyposis coli (APC) tumour suppressor gene through truncating mutations or other means is an early event in most colo-rectal cancer (CRC). The AFC gene encodes a large multifunctional protein that plays key roles in several cellular processes, including the wnt signalling pathway where an intact APC protein is essential for down regulation of β-catenin. The APC protein also plays a role in regulation of cell proliferation, differentiation, apoptosis, cell-cell adhesion, cell migration and chromosomal stability during mitosis. Acquisition of a non-functional APC gene can occur by inheritance (in the disease familial adenomatous polyposis (FAP)) or by a sporadic event in a somatic cell. Whilst there is strong epidemiological evidence that variation in diet is a major determinant of variation in CRC incidence, conventional adenoma recurrence trials in sporadic cases of the disease have been relatively unsuccessful in identifying potentially protective food components. Since the genetic basis of CRC in FAP and in sporadic CRC is similar, intervention trials in FAP gene carriers provide an attractive strategy for investigation of potential chemo-preventive agents, since smaller numbers of subjects and shorter time frames are needed. The Concerted Action Polyp Prevention (CAPP) 1 Study is using a 2×2 factorial design to test the efficacy of resistant starch (30 g raw potato starch-Hylon VII (1:1, w/w)/d) and aspirin (600 mg/d) in suppressing colo-rectal adenoma formation in young subjects with FAP. Biopsies of macroscopically-normal rectal mucosa are also being collected for assay of putative biomarkers of CRC risk.

Activity intensity is a potential determinant of activity-induced energy expenditure. Tri-axial accelerometery is the most objective measurement technique for the assessment of activity intensity, in combination with doubly-labelled water for the measurement of energy expenditure under free-living conditions. Data on the effects of subject characteristics, including body size and age, and exercise training on the relationship between activity intensity and daily energy expenditure are reviewed. Average daily metabolic rate and non-basal energy expenditure are positively related to body size. The duration and intensity of physical activities do not need to be equivalent to the energy spent on activity. Obese subjects spend more energy on physical activity but can perform fewer activities, especially high-intensity (weight-bearing) activities, because of their higher body weight. Physical activity generally declines gradually from about 60 years of age onwards. Most subjects >80 years have an activity level well below the level defined for sedentary middle-aged adults. Spending relatively more time on low-intensity activities has a negative effect on the mean physical activity level. To obtain a higher physical activity level does not necessarily imply high-intensity activities. In an average subject 25% of the activity-induced energy expenditure may be attributed to high-intensity activities. Exercise training, as a form of high-intensity activity, affects the physical activity level more in younger subjects than in elderly subjects.

Many studies have shown that overall dietary patterns, dietary components consumed, or mode of food preparation are all possibly relevant in either reducing or increasing the risk of cancer in animals or man. Yet, dietary intervention studies, stemming from laboratory and epidemiological observational studies have often failed to demonstrate the anticipated protection against cancer. One possible explanation for the discrepancy between the results of various observational and experimental chemo-prevention studies is the lack of control for biological diversity of the participants of these studies. It is suggested that future epidemiological studies provide evidence stratified by status of major metabolic polymorphisms pertinent to the study subject, and that future intervention studies take these differences into account in the design and analysis phases.

Meat quality is a term used to describe a range of attributes of meat. Consumer research suggests that tenderness is a very important element of eating quality and that variations in tenderness affect the decision to repurchase. The present paper highlights recent information on the factors that affect tenderness. While the precise aetiology is not fully understood, a number of factors have been shown to affect tenderness. Of these factors, postmortem factors, particularly temperature, sarcomere length and proteolysis, which affect the conversion of muscle to meat, appear most important. However, it is now becoming clear that variation in other factors such as the muscle fibre type composition and the buffering capacity of the muscle together with the breed and nutritional status of the animals may also contribute to the observed variation in meat tenderness.

Physical activity (PA) is a popular therapy for the prevention and treatment of bone loss and osteoporosis because it has no adverse side effects, it is low cost, and it confers additional benefits such as postural stability and fall prevention. Bone mass is regulated by mechanical loading, and is limited but not controlled by diet. The mechanism by which strain thresholds turn bone remodelling ‘on’ and ‘off ’ is known as the mechanostat theory. Research in animals has shown that optimal strains are dynamic, with a high change rate, an unusual distribution and a high magnitude of strain, but the results of randomized controlled trials in human subjects have been somewhat equivocal. In the absence of weight-bearing activity nutritional or endocrine interventions cannot maintain bone mass. Biochemical markers of bone turnover predict bone mass changes, and findings from our research group and others have shown that both acute and chronic exercise can reduce bone resorption. Similarly, Ca intervention studies have shown that supplementation can reduce bone resorption. Several recent meta-analytical reviews concur that changes in bone mass with exercise are typically 2–3%. Some of these studies suggest that Ca intake may influence the impact of PA on bone, with greater effects in Ca-replete subjects. Comparative studies between Asian (high PA, low Ca intake) and US populations (low PA, high Ca intake) suggest that PA may permit an adaptation to low Ca intakes. Whether Ca and PA interact synergistically is one of the most important questions unanswered in the area of lifestyle-related bone health research.