Synchrotron radiation-based Fourier transform IR (SR-FTIR) microspectroscopy has been developed as a rapid, direct, non-destructive and bioanalytical technique. This technique, taking advantage of synchrotron light brightness and a small effective source size, is capable of exploring the molecular chemistry within the microstructures of a biological tissue without the destruction of inherent structures at ultraspatial resolutions within cellular dimensions. This is in contrast to traditional ‘wet’ chemical methods, which, during processing for analysis, often result in the destruction of the intrinsic structures of feeds. To date there has been very little application of this technique to the study of feed materials in relation to animal nutrient utilisation. The present article reviews four applications of the SR-FTIR bioanalytical technique as a novel approach in animal nutrition and feed science research. Application 1 showed that using the SR-FTIR technique, intensities and the distribution of the biological components (such as lignin, protein, lipid, structural and non-structural carbohydrates and their ratios) in the microstructure of plant tissue within cellular dimensions could be imaged. The implication from this study is that we can chemically define the intrinsic feed structure and compare feed tissues according to spectroscopic characteristics, functional groups, spatial distribution and chemical intensity. Application 2 showed that the ultrastructural–chemical makeup and density of yellow- and brown-seeded Brassica rape could be explored. This structural–chemical information could be used for the prediction of rapeseed quality and nutritive value for man and animals and for rapeseed breeding programmes for selecting superior varieties for special purposes. More research is required to define the extent of differences that exist between the yellow- and brown-seeded Brassica rape. Application 3 showed with the SR-FTIR technique that chemical differences in the ultrastructural matrix of endosperm tissue between Harrington (malting-type) and Valier (feed-type) barley in relation to rumen degradation characteristics could be identified. The results indicated that the greater association of the protein matrix with the starch granules in the endosperm tissue of Valier barley may limit the access of ruminal micro-organisms to the starch granules and thus reduce the rate and extent of rumen degradation relative to that of Harrington barley. It is the first time that the microstructural matrix in the endosperm of barley has been revealed by using the SR-FTIR technique, which makes it possible to link feed intrinsic structures to nutrient utilisation and digestive behaviour in ruminants. Application 4 showed with the SR-FTIR technique that the chemical features of various feed protein (amide I) secondary structures (such as feather, wheat, oats and barley) could be quantified. With a multi-component fitting program (Lorentz function), the results showed feather containing about 88% β-sheet and 4% α-helix, barley containing about 17% β-sheet and 71% α-helix; oats containing about 2% β-sheet and 92% α-helix; and wheat containing about 42% β-sheet and 50% α-helix. The relative percentage of the two may influence protein value. A high percentage of β-sheet may reduce the access of gastrointestinal digestive enzymes to the protein structure. Further study is required on feed protein secondary structures in relation to enzyme accessibility and digestibility. In conclusion, the SR-FTIR technique can be used for feed science and animal nutrition research. However, the main disadvantage of this technique is the requirement for a special light source; a synchrotron beam.

We have previously shown that non-digestible saccharides (NDS) stimulate intestinal Ca absorption via tight junctions. However, the cellular mechanisms activated by the NDS are not yet known. We investigated the effects of four NDS, difructose anhydride (DFA) III, DFAIV, fructo-oligosaccharides, and maltitol, on intracellular Ca signalling in isolated rat small-intestinal enterocytes. The changes in intracellular Ca2+ concentration were measured before and after the addition of capric acid (7·5 or 15 mmol/l, a positive control), glycerol, or each NDS (1 or 10 mmol/l) to fura-2-loaded enterocytes. Treatment with capric acid or each NDS caused an immediate and dose-dependent rise in intracellular Ca2+ concentration. Mechanical and osmotic stimulation achieved by adding glycerol had no effect on intracellular Ca2+ concentration. The intracellular Ca2+ concentration in enterocytes treated with DFAIII and fructo-oligosaccharides reached a peak level at about 30 s after stimulation, but those treated with DFAIV and maltitol showed further increases after the initial rapid rise. The maximum change in intracellular Ca2+ concentration obtained by the application of maltitol was higher than that of DFAIII at 10 mmol/l. These findings suggest that each of the four NDS directly stimulates rat enterocytes, and increases intracellular Ca2+ concentration. Thus, molecular structure may be more important than the size of the NDS in the induction of Ca signalling in the cells.

The post-genomic era has been driven by the development of technologies that allow the function of cells and whole organisms to be explored at the molecular level. Metabolomics is concerned with the measurement of global sets of low-molecular-weight metabolites. Metabolite profiles of body fluids or tissues can be regarded as important indicators of physiological or pathological states. Such profiles may provide a more comprehensive view of cellular control mechanisms in man and animals, and raise the possibility of identifying surrogate markers of disease. Metabolomic approaches use analytical techniques such as NMR spectroscopy and MS to measure populations of low-molecular-weight metabolites in biological samples. Advanced statistical and bioinformatic tools are then employed to maximise the recovery of information and interpret the large datasets that are generated. Metabolomics has already been used to study toxicological mechanisms and disease processes and offers enormous potential as a means of investigating the complex relationship between nutrition and metabolism. Examples include the metabolism of dietary substrates, drug-induced disturbances of lipid metabolites in type 2 diabetes mellitus and the therapeutic effects of vitamin supplementation in the treatment of chronic metabolic disorders.

The Society for the Study of Ingestive Behaviour meets each year to discuss and highlight recent developments in our understanding of all aspects of controls of eating and drinking. The aim of this satellite was to focus on key issues in human food intake control: palatability, central and peripheral signalling, dietary restraint, macronutrients, energy density, heritability and the significance of animal models for research in man, and to bring together researchers approaching these issues from different perspectives. The presentations including live discussions are reflected in the following papers.

The aim of the present study was to assess the prevalence of the Mediterranean dietary pattern (MDP) in the population of the Balearic Islands and socio-demographic and lifestyle factors that might determine adherence to the MDP. A cross-sectional nutritional survey was carried out in the Balearic Islands between 1999 and 2000. A random sample (n 1200) of the adult population (16–65 years) was interviewed. Dietary questionnaires incorporating questions related to socio-economic status, education level, lifestyle factors and health status were utilised. Dietary habits were assessed by means of two 24 h recalls, and a quantitative food-frequency questionnaire. Adherence to the MDP was defined according to a score constructed considering the consumption of nine MDP characteristic components: high MUFA:saturated fatty acids ratio, moderate ethanol consumption, high legumes, cereals and roots, fruits, vegetables, and fish consumption, and low consumption of meat and milk. Then, socio-demographic, lifestyle and health status variables that could determine a higher or lower adherence were assessed. Adherence to the MDP among the population of the Balearic Islands was found to be 43·1 (sd 5·8) %, and was similar in all socio-demographic and lifestyle groups, with some differences according to age, sex and physical status. There was an increase in the percentage of adherence with age, which was greater in males than in females. A more physically active lifestyle was associated with a higher adherence to the MDP. The promotion of the Mediterranean lifestyle, including the MDP and greater physical activity, should be reinforced in the population of the Balearic Islands and especially in the younger generations.

Folate has recently been proposed as a new antioxidant. Folate supplementation may have a protective effect in counteracting oxidant-induced apoptotic damage. The present studies were undertaken to examine whether there is a direct link between folate levels, antioxidant capability and reduced apoptotic damage. Using an in vitro cellular model of 7-ketocholesterol (KC)-induced apoptosis, U937 cells were pre-cultured with a folate-deficient medium supplemented with various levels of folate (2–1500μmol/l) before treatment with 7-KC. Apoptotic markers, mitochondria-associated death signals and levels of reactive oxygen species were assayed. After treatment with 7-KC for 30h, low and high levels of folate supplementation significantly (P<0.05) reduced nuclear DNA loss. Only high levels of folate supplementation (>1000μmol/l) were effective in counteracting 7-KC-promoted apoptotic membrane phosphatidylserine exposure and DNA laddering. The attenuation of 7-KC-induced apoptotic damage by high-dose folate supplementation coincided with a partial normalization of mitochondria membrane potential dissipation, a suppression of cytochrome c release and an inhibition of procaspase 3 activation. The prevention of mitochondrial dysfunctions and apoptotic processes was associated with antioxidant actions of high-dose folate by a marked scavenging of intracellular superoxide. Collectively, our present results demonstrate that in vitro folate supplementation exerts differentially protective effects against 7-KC-induced damage. High-dose supplementation alleviates oxidative stress, mitochondria-associated death signalling and apoptosis induced by 7-KC. However, the in vivo relevance is not clear and requires further study.

White adipose tissue is now recognised to be a multifunctional organ; in addition to the central role of lipid storage, it has a major endocrine function secreting several hormones, notably leptin and adiponectin, and a diverse range of other protein factors. These various protein signals have been given the collective name ‘adipocytokines’ or ‘adipokines’. However, since most are neither ‘cytokines’ nor ‘cytokine-like’, it is recommended that the term ‘adipokine’ be universally adopted to describe a protein that is secreted from (and synthesised by) adipocytes. It is suggested that the term is restricted to proteins secreted from adipocytes, excluding signals released only by the other cell types (such as macrophages) in adipose tissue. The adipokinome (which together with lipid moieties released, such as fatty acids and prostaglandins, constitute the secretome of fat cells) includes proteins involved in lipid metabolism, insulin sensitivity, the alternative complement system, vascular haemostasis, blood pressure regulation and angiogenesis, as well as the regulation of energy balance. In addition, there is a growing list of adipokines involved in inflammation (TNFα, IL-1β, IL-6, IL-8, IL-10, transforming growth factor-β, nerve growth factor) and the acute-phase response (plasminogen activator inhibitor-1, haptoglobin, serum amyloid A). Production of these proteins by adipose tissue is increased in obesity, and raised circulating levels of several acute-phase proteins and inflammatory cytokines has led to the view that the obese are characterised by a state of chronic low-grade inflammation, and that this links causally to insulin resistance and the metabolic syndrome. It is, however, unclear as to the extent to which adipose tissue contributes quantitatively to the elevated circulating levels of these factors in obesity and whether there is a generalised or local state of inflammation. The parsimonious view is that the increased production of inflammatory cytokines and acute-phase proteins by adipose tissue in obesity relates primarily to localised events within the expanding fat depots. It is suggested that these events reflect hypoxia in parts of the growing adipose tissue mass in advance of angiogenesis, and involve the key controller of the cellular response to hypoxia, the transcription factor hypoxia inducible factor-1.

Selenium-enriched yeast (Se-yeast) is a common form of Se used to supplement the dietary intake of this important trace mineral. However, its availability within the European Union is under threat, owing to concerns expressed by the European Community (EC) Scientific Committee on Food that Se-yeast supplements are poorly characterised and could potentially cause the build up of Se in tissues to toxic levels. The present review examines the validity of these concerns. Diagrams of the biosynthesis and metabolism of Se compounds show which species can be expected to occur in Se-yeast preparations. Se-yeast manufacture is described together with quality-control measures applied by reputable manufacturers. The way in which speciation of Se-yeast is achieved is explained and results on amounts of Se species in various commercial products are tabulated. In all cases described, selenomethionine is the largest single species, accounting for 54–74 % of total Se. Se-yeast is capable of increasing the activity of the selenoenzymes and its bioavailability has been found to be higher than that of inorganic Se sources in all but one study. Intervention studies with Se-yeast have shown the benefit of this form in cancer prevention, on the immune response and on HIV infection. Of about one dozen supplementation studies, none has shown evidence of toxicity even up to an intake level of 800 μg Se/d over a period of years. It is concluded that Se-yeast from reputable manufacturers is adequately characterised, of reproducible quality, and that there is no evidence of toxicity even at levels far above the EC tolerable upper intake level of 300 μg/d.

The CB1 cannabinoid receptor antagonist, N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methylpyrazole-3-carboxamide (rimonabant; SR141716A), and oleoylethanolamide (OEA) are known to reduce food consumption, by, at least partially, a peripheral regulation of feeding. The effects of systemic SR141716A or OEA (5 mg/kg) administrations on food consumption in 24 h food-deprived and fed rats were investigated. In fasted rats, SR141716A and OEA produced an inhibition in food intake measurable the first 20 min following injection. The increase in ghrelin levels observed in the vehicle-injected rats was abolished in animals receiving OEA and significantly reduced with SR141716A. Neither OEA nor SR141716A modified glucagon-like peptide-1 (7–36) amide portal levels 20 min after the administration. In fed rats, plasma ghrelin levels of SR141716A- and OEA-treated rats were 35% lower as compared with those of the vehicle-injected rats. These results show an influence of cannabinoid agents on circulating ghrelin levels and suggest that their short-term action on appetite seems to be in accordance with the control of secretion of gastrointestinal orexigenic peptides, mainly expressed in the upper part of the gastrointestinal tract.

The traditional view of palatability was that it reflected some underlying nutritional deficit and was part of a homeostatically driven motivational system. However, this idea does not fit with the common observation that palatability can lead to short-term overconsumption. Here, we attempt to re-evaluate the basis of palatability, first by reviewing the role of salt-need both in the expression of liking for salty tastes, and paradoxically, in dissociating need from palatability, and second by examining the role of palatability in short-term control of appetite. Despite the clarity of this system in animals, however, most salt (NaCl) intake in man occurs in a need-free state. Similar conclusions can be drawn in relation to the palatability of food in general. Importantly, the neural systems underlying the hedonic system relating to palatability and homeostatic controls of eating are separate, involving distinct brain structures and neurochemicals. If palatability was a component of homeostatic control, reducing need-state should reduce palatability. However, this is not so, and if anything palatability exerts a stronger stimulatory effect on eating when sated, and over-consumption induced by palatability may contribute to obesity. Differential responsivity to palatability may be a component of the obese phenotype, perhaps through sensitisation of the neural structures related to hedonic aspects of eating. Together, these disparate data clearly indicate that palatability is not a simple reflection of need state, but acts to promote intake through a distinct hedonic system, which has inputs from a variety of other systems, including those regulating need. This conclusion leads to the possibility of novel therapies for obesity based on modulation of hedonic rather than homeostatic controls. Potential developments are discussed.

It has been reported that smokers have higher plasma malondialdehyde concentrations compared with non-smokers. However, smokers have also consistently been shown to have a lower intake of fruits and vegetables as well as lower plasma antioxidant concentrations. Since both the latter issues may well influence the malondialdehyde concentration, we wanted to investigate if the observed difference between smokers and non-smokers was a result of differences in antioxidant status or if a more direct effect of smoking could also be isolated. In the present study, the plasma malondialdehyde and antioxidant profiles of a cohort of smokers (n 48) and non-smokers (n 32) were compared. While there was no significant difference in the major plasma antioxidants measured, i.e. ascorbic acid, α- and γ-tocopherol and uric acid, we found a significant effect of smoking on plasma malondialdehyde (P=0·0003). Consequently, the present study suggests that lipid peroxidation as measured by plasma malondialdehyde is induced by smoking per se. While poor antioxidant status presumably also affects lipid peroxidation, it is only partly responsible for the increased level found in smokers in general.

To assess the effects of acute dietary saturated fat intake on glucose-induced insulin secretion rate (ISR), measured by the C-peptide deconvolution method, and on insulin clearance and sensitivity, five obese and five normal-weight women (controls) were studied after either a 100g oral butter load or a 100ml water load. At 120min after the oral load a hyperglycaemic clamp was performed over 180min. A dramatic increase of ISR occurred after butter compared with the water challenge in the controls (1305·6 (SE 124·1) v. 616·1 (SE 52·5) pmol/min; P<0·01) and to a lesser degree in the obese subjects (1975·0 (SE 44·1) v. 1417·5 (SE 56·0) pmol/min; P<0·05). Insulin sensitivity was impaired after butter (0·60×10−2 (SE 0·11×10−2) v. 2·26×10−2 (SE 0·32×10−2) ml/min per kgFFM per (pmol/l); P<0·01) in the controls but not in the obese group. Insulin clearance during the clamp was reduced after butter compared with after the water load only in the controls (0·89 (SE 0·22) v. 1·70 (SE 0·15) litres/min; P<0·01). The data are consistent with the hypothesis that acute excess lipid availability may lead to a compensatory elevation in glucose-induced insulin secretion as a result of the decline in insulin sensitivity and a reduced insulin clearance.

Vitamin E absorption requires the presence of fat; however, limited information exists on the influence of fat quantity on optimal absorption. In the present study we compared the absorption of stable-isotope-labelled vitamin E following meals of varying fat content and source. In a randomised four-way cross-over study, eight healthy individuals consumed a capsule containing 150 mg 2H-labelled RRR-α-tocopheryl acetate with a test meal of toast with butter (17·5 g fat), cereal with full-fat milk (17·5 g fat), cereal with semi-skimmed milk (2·7 g fat) and water (0 g fat). Blood was taken at 0, 0·5, 1, 1·5, 2, 3, 6 and 9 h following ingestion, chylomicrons were isolated, and 2H-labelled α-tocopherol was analysed in the chylomicron and plasma samples. There was a significant time (P<0·001) and treatment effect (P<0·001) in 2H-labelled α-tocopherol concentration in both chylomicrons and plasma between the test meals. 2H-labelled α-tocopherol concentration was significantly greater with the higher-fat toast and butter meal compared with the low-fat cereal meal or water (P<0·001), and a trend towards greater concentration compared with the high-fat cereal meal (P=0·065). There was significantly greater 2H-labelled α-tocopherol concentration with the high-fat cereal meal compared with the low-fat cereal meal (P<0·05). The 2H-labelled α-tocopherol concentration following either the low-fat cereal meal or water was low. These results demonstrate that both the amount of fat and the food matrix influence vitamin E absorption. These factors should be considered by consumers and for future vitamin E intervention studies.

The Expert Group on the Methodological Approaches and Current Nutritional Recommendations in Children and Adolescents was convened to consider the current situation across Europe with regard to dietary recommendations and reference values for children aged 2–18 years. Information was obtained for twenty-nine of the thirty-nine countries in Europe and a comprehensive compilation was made of the dietary recommendations current up to September 2002. This report presents a review of the concepts of dietary reference values and a comparison of the methodological approaches used in each country. Attention is drawn to the special considerations that are needed for establishing dietary reference values for children and adolescents. Tables are provided of the current dietary reference values for energy and for the macronutrients, vitamins, minerals, trace elements and water. Brief critiques are included to indicate the scientific foundations of the reference values for children and to offer, where possible, an explanation for the wide differences that exist between countries. This compilation demonstrated that there are considerable disparities in the perceived nutritional requirements of European children and adolescents. Although some of this diversity can be attributed to real physiological and environmental differences, most is due to differences in philosophy about the best methodological approach to use and in the way the theoretical approaches are applied. The report highlights the main methodological and technological issues that will need to be resolved before harmonisation can be fully considered. Solving these issues may help to improve the quality and consistency of dietary reference values across Europe. However, there are also considerable scientific and political barriers that will need to be overcome and the question of whether harmonisation of dietary reference values for children and adolescents is a desirable or achievable goal for Europe requires further consideration.