Sex differences in the ratio of fat mass (FM):fat-free mass (FFM) during weight change should differentially affect the extent of weight change during energy imbalance in men and women. In the present study, we determined FM and FFM contents by dual-energy X-ray absorptiometry and calculated the P-ratios (protein energy/total energy) of excess weight and weight loss during a randomised controlled trial of four commercial weight loss regimens. Overweight and obese women (n 210) and men (n 77) were studied at baseline and at 2 and 6 months during weight loss on four dietary regimens: Dr Atkins' New Diet Revolution; The Slim-Fast Plan; Weight-Watchers programme; Rosemary Conley's Diet and Fitness Plan. At baseline, the percentage of FFM (%FFM) and P-ratios of excess weight were 40 % and 0·071 for men and 27 % and 0·039 for women. At 2 months, men had lost twice as much weight as women and three times more FFM than women, indicating higher FFM content and P-ratios of weight loss for men, 0·052, than for women, 0·029, with no dietary effects. Between 2 and 6 months, the rate at which weight was lost decreased and the %FFM of weight loss decreased to similar low levels in men (7 %) and women (5 %): i.e. P-ratios of 0·009 and 0·006, respectively, with no dietary effects. Thus, for men compared with women, there were greater FFM content and P-ratios of weight change, which could partly, but not completely, explain their greater weight loss at 2 months. However, protein-conserving adaptations occur with increasing weight loss and over time, more extensively in men, eventually eliminating any sex difference in the composition of weight loss.

Several N-nitroso compounds (NOC) have been shown to be carcinogenic in a variety of laboratory animals, but evidence of their carcinogenicity in humans is lacking. We aimed to examine the association between NOC intake and colorectal cancer (CRC) risk and possible effect modification by vitamins C and E and protein in a large case–control study carried out in Newfoundland and Labrador and Ontario, Canada. A total of 1760 case patients with pathologically confirmed adenocarcinoma and 2481 population controls were asked to complete a self-administered FFQ to evaluate their dietary intakes 1 year before diagnosis (for cases) or interview (for controls). Adjusted OR and 95 % CI were calculated across the quintiles of NOC (measured by N-nitrosodimethylamine (NDMA)) intake and relevant food items using unconditional logistic regression. NDMA intake was found to be associated with a higher risk of CRC (highest v. lowest quintiles: OR 1·42, 95 % CI 1·03, 1·96; P for trend = 0·005), specifically for rectal carcinoma (OR 1·61, 95 % CI 1·11, 2·35; P for trend = 0·01). CRC risk also increased with the consumption of NDMA-containing meats when the highest tertile was compared with the lowest tertile (OR 1·47, 95 % CI 1·03, 2·10; P for trend = 0·20). There was evidence of effect modification between dietary vitamin E and NDMA. Individuals with high NDMA and low vitamin E intakes had a significantly increased risk than those with both low NDMA and low vitamin E intakes (OR 3·01, 95 % CI 1·43, 6·51; P for interaction = 0·017). The present results support the hypothesis that NOC intake may be positively associated with CRC risk in humans. Vitamin E, which inhibits nitrosation, could modify the effect of NDMA on CRC risk.

Short sleep duration among children and adolescents has been reported to be associated with elevated BMI and other adverse health outcomes. Food choices are one proposed mechanism through which this association may occur. In the present study, we examined whether self-reported habitual sleep duration is associated with vegetable and fruit consumption and fast food consumption. Using cross-sectional data from the National Longitudinal Study of Adolescent Health (n 13 284), we estimated three nested logistic regression models for two outcome variables: daily vegetable and fruit consumption and previous week's fast food consumption. The adjusted models included demographic and social/behavioural covariates. Self-reported habitual short sleep duration ( < 7 h/night) was associated with reduced odds of vegetable and fruit consumption compared with the recommended sleep duration (>8 h/night) (OR 0·66, P <0·001), even after adjusting for demographic and social/behavioural factors (OR 0·75, P <0·001). Short sleep duration was also associated with increased odds of fast food consumption (OR 1·40, P <0·001) even after adjustment (OR 1·20, P <0·05). Food choices are significantly associated with sleep duration and may play an important role in the mediation of the association between sleep and health among adolescents.

Diet quality is influenced by socio-economic and geographical factors. The present study sought to assess whether adolescents' diet quality is affected by their parents' socio-economic status and whether the relationship between these factors is similar in northern and southern Europe. Data collected in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study in eight European countries were analysed. Dietary intake data were recorded via repeated 24 h recalls (using specifically developed HELENA Dietary Intake Assessment Tool software) and converted into an adolescent-specific Diet Quality Index (DQI-AM). Socio-economic status was estimated through parental educational level (Par-Educ-Lev) and parental occupation level (Par-Occ-Lev) as reported by the adolescents in a specific questionnaire. The DQI-AM data were then analysed as a function of Par-Educ-Lev and Par-Occ-Lev in northern European countries (Austria, Belgium, France, Germany and Sweden) and southern European countries (Greece, Italy and Spain). We studied a total of 1768 adolescents (age 14·7 (sd 1·3) years; percentage of girls: 52·8 %; 1135 and 633 subjects from northern and southern Europe, respectively). On average, the DQI-AM score was higher in southern Europe than in northern Europe (69·1 (sd 0·1) v. 60·4 (sd 2·8), respectively; P< 0·001; Δ = 12·6 %). The DQI was positively correlated with both paternal and maternal Par-Educ-Lev. However, this association was more pronounced in northern Europe than in southern Europe (P interaction = 0·004 for the mother and 0·06 for the father). The DQI was also positively correlated with Par-Occ-Lev (all P trends < 0·01), but this correlation was independent of the geographical area (P interaction = 0·51 for the mother and 0·50 for the father). In conclusion, Par-Educ-Lev and Par-Occ-Lev are associated with diet quality in adolescents in Europe. However, this association differs between northern Europe and southern Europe.

Se metabolism in humans is not well characterised. Currently, the estimates of Se absorption, whole-body retention and excretion are being obtained from balance and tracer studies. In the present study, we used gamma camera imaging to evaluate the whole-body retention and distribution of radiolabelled selenomethionine (SeMet), the predominant form of Se present in foods. A total of eight healthy young men participated in the study. After consumption of a meal containing 4 MBq [75Se]l-SeMet ([75Se]SeMet), whole-body gamma camera scanning was performed for 45 min every hour over a 6 h period, every second hour for the next 18 h and once on each of the subsequent 6 d. Blood, urine and faecal samples were collected to determine the plasma content of [75Se]SeMet as well as its excretion in urine and faeces. Imaging showed that 87·9 (sd 3·3) % of the administered activity of [75Se]SeMet was retained within the body after 7 d. In contrast, the measured excretion in urine and faeces for the 7 d period was 8·2 (sd 1·1) % of the activity. Time–activity curves were generated for the whole body, stomach, liver, abdomen (other than the stomach and the liver), brain and femoral muscles. Gamma camera imaging allows for the assessment of the postprandial absorption of SeMet. This technique may also permit concurrent studies of organ turnover of SeMet.

Fractionation of N isotopes occurs in many metabolic reactions which causes tissue proteins to become enriched in 15N while urea (urine) is depleted in 15N relative to the diet. We investigated 15N enrichment of whole plasma and its relationship with feed conversion efficiency (FCE) in growing beef heifers (n 84) offered 2 kg/d of concentrates with grass silage ad libitum. Heifers were on average 299 (sd 48·3) d old and weighed 311 (sd 48·8) kg. Plasma was obtained on day 79 (n 84) of the experiment and from a subset of animals (n 20) on four occasions between days 16 and 79. Silage DM intake (DMI) averaged 4·1 (sd 0·74) kg/d and concentrate DMI was 1·72 kg/d. Mean mid-test live weight was 333 (sd 47·6) kg, daily gain was 0·53 (sd 0·183) kg, FCE (g live-weight gain/g DMI) was 0·09 (sd 0·028) and residual feed intake (RFI) was 0 (sd 0·428). N isotopic fractionation (Δ15N; plasma δ15N − diet δ15N) averaged 3·58 ‰ on day 79 (n 84) and 3·90 ‰ for the subset of heifers. There was no relationship between Δ15N and RFI. Plasma δ15N and Δ15N were related to both FCE (negative) and animal weight (positive) for the whole population, and repeatable for the subset of animals over four time points. These relationships of Δ15N with FCE and animal weight are consistent with the anticipated negative relationship with N-use efficiency. There is potential to use Δ15N to provide rapid, low-cost estimates of FCE in cattle.

Maternal energy restriction during pregnancy predisposes to metabolic alterations in the offspring. The present study was designed to evaluate phenotypic and metabolic consequences following maternal undernutrition in an obese pig model and to define the potential role of hypothalamic gene expression in programming effects. Iberian sows were fed a control or a 50 % restricted diet for the last two-thirds of gestation. Newborns were assessed for body and organ weights, hormonal and metabolic status, and hypothalamic expression of genes implicated in energy homeostasis, glucocorticoid function and methylation. Weight and adiposity were measured in adult littermates. Newborns of the restricted sows were lighter (P <0·01), but brain growth was spared. The plasma concentration of TAG was lower in the restricted newborns than in the control newborns of both the sexes (P <0·01), while the concentration of cortisol was higher in females born to the restricted sows (P <0·04), reflecting a situation of metabolic stress by nutrient insufficiency. A lower hypothalamic expression of anorexigenic peptides (LEPR and POMC, P <0·01 and P <0·04, respectively) was observed in females born to the restricted sows, but no effect was observed in the males. The expression of HSD11B1 gene was down-regulated in the restricted animals (P <0·05), suggesting an adaptive mechanism for reducing the harmful effects of elevated concentrations of cortisol. At 4 and 7 months of age, the restricted females were heavier and fatter than the controls (P< 0·01). Maternal feed restriction induces asymmetrical growth retardation and metabolic alterations in the offspring. Differences in gene expression at birth and higher growth and adiposity in adulthood suggest a female-specific programming effect for a positive energy balance, possibly due to overexposure to endogenous stress-induced glucocorticoids.

In the present study, we investigated the association between dietary intake of carbohydrates and the risk of type 2 diabetes. Incident cases of diabetes (n 749) were identified and compared with a randomly selected subcohort of 3496 participants aged 40–79 years. For dietary assessment, we used 7 d food diaries administered at baseline. We carried out modified Cox proportional hazards regression analyses and compared results obtained from the different methods of adjustment for total energy intake. Dietary intakes of total carbohydrates, starch, sucrose, lactose or maltose were not significantly related to diabetes risk after adjustment for confounders. However, in the residual method for energy adjustment, intakes of fructose and glucose were inversely related to diabetes risk. The multivariable-adjusted hazard ratios (HR) of diabetes comparing the extreme quintiles of intake were 0·79 (95 % CI 0·59, 1·07; P for trend = 0·03) for glucose and 0·62 (95 % CI 0·46, 0·83; P for trend = 0·01) for fructose. In the nutrient density method, only fructose was inversely related to diabetes risk (HR 0·65, 95 % CI 0·48, 0·88). The replacement of 5 % energy intake from SFA with an isoenergetic amount of fructose was associated with a 30 % lower diabetes risk (HR 0·69, 95 % CI 0·50, 0·96). Results of the standard and energy partition methods were similar to those of the residual method. These prospective findings suggest that the intakes of starch and sucrose are not associated, but that those of fructose and glucose are inversely associated with diabetes risk. Whether the inverse associations with fructose and glucose reflect the effect of substitution of these carbohydrate subtypes with other nutrients (i.e. SFA), their net higher intake or other nutrients associated with their intake remains to be established through further investigation.

The objective of the present study was to investigate whether a previously reported apparent negative relationship between fat mass and daily physical activity in Japanese adult women would also be observed in Japanese adult men. The subjects were grouped into quartiles of BMI and body fat percentage (%BF). The number of steps walked each day and the duration of light- to vigorous-intensity physical activity were assessed by an accelerometer over the same period of time as for the doubly labelled water experiment. The results showed that BMI negatively correlated with the number of steps and time spent in moderate-intensity physical activity, whereas %BF showed a negative relationship with physical activity-related energy expenditure (PAEE)/body weight (BW) and physical activity level. The analysis of data using %BF quartiles revealed that PAEE/BW decreased from the second quartile in which the BMI was < 25 kg/m2. These observations are similar to those reported in our previous study in Japanese adult women. These cross-sectional studies cannot prove causality, and that obesity causes physical inactivity may be the case. However, the results of the present study provide information regarding which physical activity variables should be used in longitudinal studies.

Dairy products have previously been reported to be associated with beneficial effects on body weight and metabolic risk markers. Moreover, primary data from the Diet, Obesity and Genes (DiOGenes) study indicate a weight-maintaining effect of a high-protein–low-glycaemic index diet. The objective of the present study was to examine putative associations between consumption of dairy proteins and changes in body weight and metabolic risk markers after weight loss in obese and overweight adults. Results were based on secondary analyses of data obtained from overweight and obese adults who completed the DiOGenes study. The study consisted of an 8-week weight-loss phase and a 6-month weight-maintenance (WM) phase, where the subjects were given five different diets varying in protein content and glycaemic index. In the present study, data obtained from all the subjects were pooled. Dairy protein intake was estimated from 3 d dietary records at two time points (week 4 and week 26) during the WM phase. Body weight and metabolic risk markers were determined at baseline (week − 9 to − 11) and before and at the end of the WM phase (week 0 and week 26). Overall, no significant associations were found between consumption of dairy proteins and changes in body weight and metabolic risk markers. However, dairy protein intake tended to be negatively associated with body weight gain (P= 0·08; β = − 0·17), but this was not persistent when controlled for total protein intake, which indicates that dairy protein adds no additional effect to the effect of total protein. Therefore, the present study does not report that dairy proteins are more favourable than other proteins for body weight regulation.

High consumption of refined grains, particularly white rice, has been reported to be associated with a higher risk of type 2 diabetes. Therefore, in the present study, we evaluated the association between rice and noodle consumption and markers of glucose homeostasis, inflammation and dyslipidaemia in an Asian population. We carried out a population-based cross-sectional study in 2728 Singaporean Chinese men and women aged between 24 and 92 years. Rice and noodle intake was assessed using a validated FFQ and studied in relation to glycaemic (fasting glucose, glycated Hb, homeostasis model assessment (HOMA) index for insulin resistance (HOMA-IR) and HOMA index for β-cell function (HOMA-β)), inflammatory (plasma adiponectin and C-reactive protein (CRP)) and lipid (fasting TAG and HDL-cholesterol (HDL-C)) markers. We used multiple linear regression analyses with adjustment for total energy intake and sociodemographic, anthropometric (BMI and waist:hip ratio) and lifestyle factors. Higher rice consumption was found to be associated with higher fasting glucose concentrations (0·81 % higher values per portion increment; 95 % CI 0·09, 1·54) and HOMA-IR (4·62 %; 95 % CI 1·29, 8·07). Higher noodle consumption was also found to be significantly associated with higher fasting glucose concentrations (1·67 %; 95 % CI 0·44, 2·92), HOMA-IR (6·17 %; 95 % CI 0·49, 12·16) and fasting TAG concentrations (9·17 %; 95 % CI 3·44, 15·22). No significant association was observed between rice and noodle consumption and adiponectin, CRP and HDL-C concentrations or HOMA-β in the fully adjusted model. These results suggest that high consumption of rice and noodles may contribute to hyperglycaemia through greater insulin resistance and that this relationship is independent of adiposity and systemic inflammation.

Prevalence rates of malnutrition vary considerably internationally, partly due to differences in measurement methodology and instruments. In the present study, the same measurement methodology and instruments were used in The Netherlands, Germany and Austria. The aim of the present study was to investigate whether resident characteristics influence possible differences in malnutrition prevalence between countries. The study followed a cross-sectional, multi-centre design that measured malnutrition in nursing home residents from The Netherlands, Germany and Austria. Resident data were gathered using a standardised questionnaire. Malnutrition was operationalised using BMI, unintentional weight loss and nutritional intake. Data were analysed using an association model. The prevalence rates of malnutrition in The Netherlands, Germany and Austria were 18·3, 20·1 and 22·5 %, respectively. The multivariate generalised estimating equation (GEE) logistic regression analysis showed that sex, age, care dependency, the mean number of diseases and some specific diseases were influencing factors for whether the resident was malnourished or not. The OR of malnutrition in the three countries declined after including the influencing factors resulting from the multivariate GEE analysis. The present study reveals that differences in the prevalence rates of malnutrition in nursing homes in The Netherlands, Germany and Austria are influenced by different resident characteristics. Since other country-related factors could also play an important role in influencing differences in the prevalence rates of malnutrition between the countries (structural and process factors of malnutrition care policy). We recommend the investigation of these factors in future studies.

The behavioural impact of an imposed bout of prolonged sitting is yet to be investigated in the paediatric population. The objective of the present study was to determine the acute effect of prolonged sitting on ad libitum food intake and spontaneous physical activity (PA) levels in healthy children and youth. A total of twenty healthy youth (twelve males and eight females) aged 10–14 years, with a mean BMI of 18·6 (sd 4·3) kg/m2, were exposed to three experimental conditions in a random order: (1) a day of uninterrupted sitting (Sedentary); (2) a day of sitting interrupted with a 2 min light-intensity walk break every 20 min (Breaks); (3) a day of sitting interrupted with a 2 min light-intensity walk break every 20 min as well as 2 × 20 min of moderate-intensity PA (Breaks+PA). Food intake (ad libitum buffet meal) and PA (accelerometry for 24 h) were assessed following exposure to each experimental condition. Despite significant differences in sedentary behaviour and activity levels during the three in-laboratory sessions (all P< 0·01), we did not observe any differences in ad libitum food intake immediately following exposure to each experimental condition or any changes in the levels of sedentary behaviour or PA in the 24 h following exposure to each experimental condition (all P>0·25). These findings suggest that children and youth may not compensate for an imposed bout of sedentary behaviour by reducing subsequent food intake or increasing PA levels.

The present study was conducted to obtain a comprehensive overview of oligosaccharides present in the milk of a variety of important domestic animals including cows, goats, sheep, pigs, horses and dromedary camels. Using an analytical workflow that included ultra-performance liquid chromatography–hydrophilic interaction liquid chromatography with fluorescence detection coupled to quadrupole time-of-flight MS, detailed oligosaccharide libraries were established. The partial or full characterisation of the neutral/fucosylated, phosphorylated and sialylated structures was facilitated by sequencing with linkage- and sugar-specific exoglycosidases. Relative peak quantification of the 2-aminobenzamide-labelled oligosaccharides provided additional information. Milk from domestic animals contained a much larger variety of complex oligosaccharides than was previously assumed, and thirteen of these structures have been identified previously in human milk. The direct comparison of the oligosaccharide mixtures reflects their role in the postnatal maturation of different types of gastrointestinal systems, which, in this way, are prepared for certain post-weaning diets. The potential value of animal milk for the commercial extraction of oligosaccharides to be used in human and animal health is highlighted.

The present study investigated the effect of aroma exposure time and aroma concentration on ad libitum intake and subjective satiation. In a within-subject study, thirty-eight unrestrained, healthy female participants (age: 18–39 years; BMI: 18·5–26·0 kg/m2) were asked to consume tomato soup during lunchtime, until they felt comfortably full. Every 30 s, the participants consumed 10 g of a bland soup base while tomato soup aroma was delivered separately through the nose via a retronasal tube that was attached to an olfactometer. This gave the impression of consuming real tomato soup. For each sip, the aroma varied in exposure time (3 and 18 s) and concentration (5 × ), resulting in four different test conditions. Ad libitum food intake and appetite profile parameters were measured. A 9 % lower food intake was observed when the participants were exposed to the condition with 18 s exposure time and a high concentration than when exposed to the other three conditions. These results indicate that changing the retronasal aroma release by aroma concentration and aroma exposure time affects food intake.