To study the absorption of microbial lysine in growing rabbits, a labelled diet (supplemented with 15NH4Cl) was administered to six animals (group ISOT); a control group (CTRL, four rabbits) received a similar, but unlabelled, diet. Diets were administered for 30d. An additional group of six animals were fed the unlabelled diet for 20d and then the labelled diet for 10d while wearing a neck collar to avoid caecotrophy (group COLL), in order to discriminate it from direct intestinal absorption. At day 30 animals were slaughtered and caecal bacteria and liver samples taken. The 15N enrichment in amino acids of caecal bacteria and liver were determined by GC–combustion/isotope ratio MS. Lysine showed a higher enrichment in caecal microflora (0·925 atom% excess, APE) than liver (0·215 APE) in group ISOT animals, confirming the double origin of body lysine: microbial and dietary. The COLL group showed a much lower enrichment in tissue lysine (0·007 (se 0·0029) APE for liver). Any enrichment in the latter animals was due to direct absorption of microbial lysine along the digestive tract, since recycling of microbial protein (caecotrophy) was avoided. In such conditions liver enrichment was low, indicating a small direct intestinal absorption. From the ratio of [15N]lysine enrichment between liver and bacteria the contribution of microbes to body lysine was estimated at 23%, with 97% of this arising through caecotrophy. Absorption of microbial lysine through caecotrophy was 119 (se 4·0) mg/d, compared with 406 (se 1·8) mg/d available from the diet. This study confirms the importance of caecotrophy in rabbit nutrition (15% of total protein intake).

A series of experiments was conducted to determine the effects of a fibrolytic enzyme preparation (enzyme 1; E1) on the in vitro fermentation of lucerne incubated with equine faecal inocula. In experiment 1, high-temperature-dried (HT) lucerne was treated with five levels of E1 (0 to 2·4ml/g DM) and incubated at 50°C for 20h. Samples then received a simulated foregut digestion (SFD) treatment before DM and NSP analysis. In experiment 2, HT lucerne was treated with the same enzyme levels used in experiment 1. Samples were then split into two groups; plus or minus an SFD treatment before in vitro fermentation using an equine faecal inoculum. In experiment 3, fresh and wilted lucerne were treated with the same levels of E1 as experiments 1 and 2, incubated at 50°C for 20h, then fermented in vitro. For experiment 4, fresh and wilted lucerne were treated with low levels (0 to 0·008ml/g DM) of E1 before fermentation. E1 significantly (P<0·05) enhanced DM and NSP losses from HT lucerne following SFD treatment compared with the control. High levels of E1 significantly (P<0·05) enhanced the rate, but not extent, of fermentation of HT, wilted and fresh lucerne; however, low levels of E1 were ineffective. At higher application levels, E1 appears to have considerable potential to enhance the nutritive value of lucerne for horses. Information on the fermentation kinetics of the substrates was valuable; all end-point measurements showed no effect of enzyme treatment.

Adding prebiotics or probiotics to infant formula to improve the intestinal flora of formula-fed infants is considered to be a major innovation. Several companies have brought relevant formulations onto the market. However, comparative data on the effects of pre- and probiotics on the intestinal microflora of infants are not available. The present study aimed to compare the effects of infant formula containing a mixture of galacto- and fructo-oligosaccharides or viable Bifidobacterium animalis on the composition and metabolic activity of the intestinal microflora. Before birth, infants were randomised and double blindly allocated to one of three formulas. The prebiotic (GOS/FOS) group (n 19) received regular infant formula supplemented with a mixture of galacto-oligosaccharides and fructo-oligosaccharides (6g/l). The probiotic (Bb-12) group (n 19) received the same formula supplemented with 6·0×1010 viable cells of B. animalis per litre. The standard group (n 19) received non-supplemented regular formula. A group of sixty-three breast-fed infants was included as a reference group. Faecal samples were taken at postnatal day 5 and 10, and week 4, 8, 12 and 16. Compared with the groups fed Bb-12 and standard formula, the GOS/FOS formula group showed higher faecal acetate ratio (69·7% (sem 2·7), 69·9% (sem 3·9) and 82·2% (sem 5·3); P<0·05) and lactate concentration (11·3 (sem 7·9), 3·1 (sem 2·3) and 34·7 (sem 10·7) mmol/kg faeces) and lower pH (6·6 (sem 0·2), 7·1 (sem 0·2) and 5·6 (sem 0·2); P<0·05) at 16 weeks. Differences in percentage of bifidobacteria between the GOS/FOS (59·2% (sem 7·7)), Bb-12 (52·7% (sem 8·0)) and the standard (51·8% (sem 6·4)) groups were not statistically significant at 16 weeks. Feeding infants GOS/FOS formula resulted in a similar effect on metabolic activity of the flora as in breast-fed infants. In the Bb-12 group, composition and metabolic activity of the flora were more similar to those of the standard group.

We previously showed that conjugated linoleic acid (CLA) increases 15-keto-dihydro-prostaglandin F2α, a marker for cyclooxygenase-mediated lipid peroxidation and thus an indicator of cyclooxygenase-mediated inflammation. The aim of the present study was to investigate the effects of CLA on other indicators of inflammation in human subjects, including C-reactive protein, TNF-α, TNF-α receptors 1 and 2, and vascular cell adhesion molecule-1. In a double-blind, placebo-controlled study, fifty-three human subjects were supplemented with a mixture (4·2g/d) of the isomers cis-9,trans-11 CLA and trans-10,cis-12 CLA or control oil for 3 months. CLA supplementation increased levels of C-reactive protein (P=0·003) compared with the control group. However, no changes in TNF-α, TNF-α receptors 1 and 2, and vascular cell adhesion molecule-1 were detected.

Despite intense discussion of the glycaemic index (GI) and glycaemic load (GL) concepts, data on the GI or GL levels in the diet of children are scarce. The present analysis determined trends in the levels of GI or GL of healthy children from 1990 to 2002 and examined the contribution of carbohydrate (CHO) sources to the overall GL, and the relationships of the GI and GL to the overall dietary quality. The analysis includes three cohorts of participants from the Dortmund Nutritional and Anthropometrical Longitudinally Designed study, aged 7–8 years in 1990 (n 53), 1996 (n 46) and 2002 (n 56). A GI value was assigned to all CHO foods recorded over three consecutive days. In comparison with 1990, 7–8-year-old children in 2002 had slightly higher GI (56·5 v. 55·1%; P=0·03) and GL (17·5 v. 16·7g/MJ; P=0·04) levels. In all three time periods the combined contribution of the ‘tolerated food groups’ (i.e. sweets, soft drinks, cakes and cookies, and salty snacks) to the overall GL exceeded that of bread and rolls (1990, 31 v. 24%; 1996, 29 v. 31%; 2002, 28 v. 25%). Conversely, rice and fried or mashed potatoes had only a minor impact. Children in the lowest GI tertile, but not those in the lowest GL tertile, had a better nutrient profile and a more favourable food choice. In conclusion, partial replacement of high-GI ‘tolerated food groups’ for low-GI foods would help to reverse the slight recent increases in GI and GL, and to improve the overall dietary quality of 7–8-year-old children.

Si may play an important role in bone formation and connective tissue metabolism. Although biological interest in this element has recently increased, limited literature exists on the Si content of foods. To further our knowledge and understanding of the relationship between dietary Si and human health, a reliable food composition database, relevant for the UK population, is required. A total of 207 foods and beverages, commonly consumed in the UK, were analysed for Si content. Composite samples were analysed using inductively coupled plasma–optical emission spectrometry following microwave-assisted digestion with nitric acid and H2O2. The highest concentrations of Si were found in cereals and cereal products, especially less refined cereals and oat-based products. Fruit and vegetables were highly variable sources of Si with substantial amounts present in Kenyan beans, French beans, runner beans, spinach, dried fruit, bananas and red lentils, but undetectable amounts in tomatoes, oranges and onions. Of the beverages, beer, a macerated whole-grain cereal product, contained the greatest level of Si, whilst drinking water was a variable source with some mineral waters relatively high in Si. The present study provides a provisional database for the Si content of UK foods, which will allow the estimation of dietary intakes of Si in the UK population and investigation into the role of dietary Si in human health.

Si has been suggested as an essential element, and may be important in optimal bone, skin and cardiovascular health. However, there are few estimates of dietary Si intakes in man, especially in a UK population. Following the development of a UK food composition database for Si, the aim of the present study was to investigate dietary intakes of Si amongst healthy women aged over 60 years and to identify important food sources of Si in their diet. Healthy, post-menopausal female subjects (>60 years of age; n 209) were recruited from the general population around Dundee, Scotland as part of an unrelated randomised controlled intervention study where dietary intake was assessed using a self-administered, semi-quantitative food-frequency questionnaire at five time-points over a 2-year period. Food composition data on the Si content of UK foods was used to determine the Si content of food items on the food-frequency questionnaire. Mean Si intake was 18·6 (sd 4·6) mg and did not vary significantly across the 2 years of investigation. Cereals provided the greatest amount of Si in the diet (about 30%), followed by fruit, beverages (hot, cold and alcoholic beverages combined) and vegetables; together these foods provided over 75% about Si intake. Si intakes in the UK appear consistent with those reported previously for elderly women in Western populations, but lower than those reported for younger women or for men.

Goitre has been declining in Italy since the 1970s and because active prophylaxis (AP) has been very limited, it has been suggested that in most places the decline was due to silent prophylaxis (SP). SP is related to the natural increase in iodine intake because of higher consumption of iodine-rich products associated with socioeconomic development. The hypothesis tested in the present study is that SP has increased iodine intake in Italy with subsequent reduction of goitre and that such changes can be quantified. The analysis is based on surveys carried out between the 1970s and the 1990s where goitre and urinary iodine, a proxy of consumption, were measured in schoolchildren. The contribution of the SP can be quantified in an annual increase in urinary iodine excretion between 2·1 and 4μg/l, and an annual decline in goitre prevalence between 2·1 and 3·6%. In the few areas with AP, there was an annual increase in urinary iodine between 6·5 and 13·1μg/l, while the average annual decline of goitre was between 4·4 and 10%. The present results could be used by policy-makers to predict the future trends in the excretion of urinary iodine and prevalence of goitre in Italy with and without AP. AP is about three times faster than SP in increasing iodine intake, but policy-makers should estimate the incremental cost-effectiveness of AP net of the iodine increase already occurring naturally with the SP.

Inverse associations between whole-grain food consumption and risk of CVD, some cancers and type 2 diabetes have been reported. However, there are few reports of whole-grain intake, particularly among young people. The objective of the present study was to estimate whole-grain intake in a nationally representative sample of young people aged 4–18 years living in Great Britain. Whole-grain intake was estimated using 7d weighed dietary records from 1583 young people who participated in the cross-sectional National Diet and Nutrition Survey in 1997. Whole-grain intake was quantified from the consumption of all foods containing ≥10% whole-grain content. Median whole-grain intake was 7g/d (interquartile range 0–19g/d), with a corresponding mean of 13 (sd18) g/d. Intake was significantly lower among young people whose head of household had a manual occupation, but did not differ significantly by sex, age, region or season. There was no whole-grain intake for 27% of participants. The percentages for less than one and less than three 16g amounts of whole-grain intake per d were 70 and 94, respectively, while corresponding percentages based on 20g amounts were 76 and 97. Foods with <51% whole-grain content provided 28% of whole-grain intake overall, with a higher percentage in older adolescents. The main sources of whole-grain intake were breakfast cereals (56%) and bread (25%). The present study provides the first quantification of absolute whole-grain intake from all significant food sources in any representative age group in the UK. Although there is some debate regarding the quantity of whole grains required for good health, whole-grain intake among British young people is low.

The present study investigates the prevalence of misreporting of energy in the Malmö Diet and Cancer cohort, and examines anthropometric, socio-economic and lifestyle characteristics of the misreporters. Further, the influence of excluding misreporters on risk estimates of post-menopausal breast cancer was examined. Information of reported energy intake (EI) was obtained from a modified diet history method. A questionnaire provided information on lifestyle and socio-economic characteristics. Individual physical activity level (PAL) was calculated from self-reported information on physical activity at work, leisure time physical activity and household work, and from estimates of hours of sleeping, self-care and passive time. Energy misreporting was defined as having a ratio of EI to BMR outside the 95% CI limits of the calculated PAL. Logistic regression analysed the risk of being a low-energy reporter or a high-energy reporter. Almost 18% of the women and 12% of the men were classified as low-energy reporters, 2·8% of the women and 3·5% of the men were classified as high-energy reporters. In both genders high BMI, large waist circumference, short education and being a blue-collar worker were significantly associated with low-energy reporting. High-energy reporting was significantly associated with low BMI, living alone and current smoking. The results add support to the practice of energy adjustment as a means to reduce the influence of errors in risk assessment.

The objective of the present study was to investigate the contribution of intra-individual variance of resting energy expenditure (REE) to interindividual variance in REE. REE was measured longitudinally in a sample of twenty-three healthy men using indirect calorimetry. Over a period of 2 months, two consecutive measurements were done in the whole group. In subgroups of seventeen and eleven subjects, three and four consecutive measurements were performed over a period of 6 months. Data analysis followed a standard protocol considering the last 15min of each measurement period and alternatively an optimised protocol with strict inclusion criteria. Intra-individual variance in REE and body composition measurements (CVintra) as well as interindividual variance (CVinter) were calculated and compared with each other as well as with REE prediction from a population-specific formula. Mean CVintra for measured REE and fat-free mass (FFM) ranged from 5·0 to 5·6% and from 1·3 to 1·6%, respectively. CVintra did not change with the number of repeated measurements or the type of protocol (standard v. optimised protocol). CVinter for REE and REE adjusted for FFM (REEadj) ranged from 12·1 to 16·1% and from 10·4 to 13·6%, respectively. We calculated total error to be 8%. Variance in body composition (CVintra FFM) explains 19% of the variability in REEadj, whereas the remaining 81% is explained by the variability of the metabolic rate (CVintra REE). We conclude that CVintra of REE measurements was neither influenced by type of protocol for data analysis nor by the number of repeated measurements. About 20% of the variance in REEadj is explained by variance in body composition.

Recent findings suggest that Western diets based on highly palatable foods are likely to be much less satiating than more traditional diets or those typical of less developed countries. In particular, some alternative crops (for example, buckwheat, oat, barley, spelt, rye, quinoa, amaranth) seem to be of great nutritional interest and to represent important recipes for healthier and typical regional foods. The objective of the present study was to investigate the effect on subsequent food intake and feelings of satiety of alternative oat bread, oat and buckwheat pasta and of quinoa as compared with their wheat counterparts and rice, respectively. Three different experiments (one specific for each alternative crop food) were conducted, all with a within-subjects design. The preloading paradigm strategy was used. Results showed that preload energy level influenced total energy intake (preload plus ad libitum test meal intake), larger preloads inducing more eating than smaller preloads. No effect of formulation was observed on energy intake, as the consumption of alternative crop formulations did not decrease the total energy intake as compared with that of the counterparts. Satiating efficiency indices (SEI) for alternative crop foods were higher with respect to traditional cereal foods. In particular, white bread was the least satisfying food (SEI =0·2) and the different time of consumption (for lunch or as a snack) did not affect energy intake. In conclusion, oat or buckwheat formulations, and also quinoa, may be exploited for their potential impact on eating behaviour, particularly considering they are good sources of functional substances.

Studies consistently show the beneficial effects of eating nuts, but as high-energy foods, their regular consumption may lead to weight gain. We tested if daily consumption of walnuts (approximately 12% energy intake) for 6 months would modify body weight and body composition in free-living subjects. Ninety participants in a 12-month randomized cross-over trial were instructed to eat an allotted amount of walnuts (28–56g) during the walnut-supplemented diet and not to eat them during the control diet, with no further instruction. Subjects were unaware that body weight was the main outcome. Dietary compliance was about 95% and mean daily walnut consumption was 35g during the walnut-supplemented diet. The walnut-supplemented diet resulted in greater daily energy intake (557kJ (133kcal)), which should theoretically have led to a weight gain of 3·1kg over the 6-month period. For all participants, walnut supplementation increased weight (0·4 (se 0·1) kg), BMI (0·2 (se 0·1) kg/m2), fat mass (0·2 (se 0·1) kg) and lean mass (0·2 (se 0·1) kg). But, after adjusting for energy differences between the control and walnut-supplemented diets, no significant differences were observed in body weight or body composition parameters, except for BMI (0·1 (se 0·1) kg/m2). The weight gain from incorporating walnuts into the diet (control→walnut sequence) was less than the weight loss from withdrawing walnuts from the diet (walnut→control sequence). Our findings show that regular walnut intake resulted in weight gain much lower than expected and which became non-significant after controlling for differences in energy intake.