A major limitation in nutritional science is the lack of understanding of the nutritional intake of free-living people. There is an inverse relationship between accuracy of reporting of energy intake by all current nutritional methodologies and body weight. In this pilot study we aim to explore whether using a novel lightweight, wearable micro-camera improves the accuracy of dietary intake assessment. Doubly labelled water (DLW) was used to estimate energy expenditure and intake over a 14-d period, over which time participants (n 6) completed a food diary and wore a micro-camera on 2 of the days. Comparisons were made between the estimated energy intake from the reported food diary alone and together with the images from the micro-camera recordings. There was an average daily deficit of 3912 kJ using food diaries to estimate energy intake compared with estimated energy expenditure from DLW (P=0·0118), representing an under-reporting rate of 34 %. Analysis of food diaries alone showed a significant deficit in estimated daily energy intake compared with estimated intake from food diary analysis with images from the micro-camera recordings (405 kJ). Use of the micro-camera images in conjunction with food diaries improves the accuracy of dietary assessment and provides valuable information on macronutrient intake and eating rate. There is a need to develop this recording technique to remove user and assessor bias.

Although the effects of dietary fat and carbohydrate on satiety are well documented, little is known about the impact of these macronutrients on food hedonics. We examined the effects of ad libitum and isoenergetic meals varying in fat and carbohydrate on satiety, energy intake and food hedonics. In all, sixty-five overweight and obese individuals (BMI=30·9 (sd 3·8) kg/m2) completed two separate test meal days in a randomised order in which they consumed high-fat/low-carbohydrate (HFLC) or low-fat/high-carbohydrate (LFHC) foods. Satiety was measured using subjective appetite ratings to calculate the satiety quotient. Satiation was assessed by intake at ad libitum meals. Hedonic measures of explicit liking (subjective ratings) and implicit wanting (speed of forced choice) for an array of HFLC and LFHC foods were also tested before and after isoenergetic HFLC and LFHC meals. The satiety quotient was greater after ad libitum and isoenergetic meals during the LFHC condition compared with the HFLC condition (P=0·006 and P=0·001, respectively), whereas ad libitum energy intake was lower in the LFHC condition (P<0·001). Importantly, the LFHC meal also reduced explicit liking (P<0·001) and implicit wanting (P=0·011) for HFLC foods compared with the isoenergetic HFLC meal, which failed to suppress the hedonic appeal of subsequent HFLC foods. Therefore, when coupled with increased satiety and lower energy intake, the greater suppression of hedonic appeal for high-fat food seen with LFHC foods provides a further mechanism for why these foods promote better short-term appetite control than HFLC foods.

Many children’s food products highlight positive attributes on their front-of-package labels in the form of nutrient claims. This cross-sectional study investigated all retailed packaged foods (n 5620) in a major Brazilian supermarket, in order to identify the availability of products targeted at children, and to compare the nutritional content of products with and without nutrient claims on labels. Data on energy, carbohydrate, protein, fibre, Na and total and SFA content, along with the presence and type of nutrient claims, were obtained in-store from labels of all products. Products targeted at children were identified, divided into eight food groups and compared for their nutritional content per 100 g/ml and the presence of nutrient claims using the Mann–Whitney U test (P<0·05). Of the 535 food products targeted at children (9·5 % of all products), 270 (50·5 %) displayed nutrient claims on their labels. Children’s products with nutrient claims had either a similar or worse nutritional content than their counterparts without nutrient claims. The major differences among groups were found in Group 8 (e.g. sauces and ready meals), in which children’s products bearing nutrient claims had higher energy, carbohydrate, Na and total and SFA content per 100 g/ml than products without nutrient claims (P<0·05). This suggests that, to prevent misleading parents who are seeking healthier products for their children, the regulation on the use of nutrient claims should be revised, so that only products with appropriate nutrient profiles are allowed to display them.

We aimed to study the fate of fat during digestion. For this purpose, we validated and investigated the non-invasive quantification of gastric and duodenal fat emptying and emulsion processing (creaming and phase separation) using the MRI method iterative decomposition with echo asymmetry and least squares estimation (IDEAL). In total, twelve healthy subjects were studied on two separate visits in a single-blind, randomised, cross-over design study. IDEAL was utilised to repeatedly acquire quantitative fat fraction maps of the gastrointestinal tract after infusion of one of two fat emulsions: E1 (acid stable, droplet size 0·33 mm) and E4 (acid unstable, 0·38 mm). In vitro and in vivo validation was carried out using diluted emulsion and gastric content samples, respectively, and resulted in Lin’s concordance correlation coefficients of 1·00 (95 % CI 0·98, 1·00) and 0·91 (95 % CI 0·87, 0·94), respectively. Fat fraction maps and intragastric emulsion profiles enabled the identification of features of intraluminal phase separation and creaming that were not visible in conventional MRI. Gastric fat emptying was faster for E4 compared with E1 with a difference of 2·5 (95 % CI 1·9, 3·1) ml/h. Duodenal content volumes were larger for E1 than for E4 with a difference of 4·9 (95 % CI 3·9, 8·5) ml. This study demonstrated that with IDEAL it was possible (1) to visualise the intragastric and duodenal fat distribution and (2) to quantify the differences in emptying, phase separation and creaming of an acid-stable and an acid-unstable emulsion. This method has potential to bridge the gap between current in vitro digestive models and in vivo behaviour and to be applied in the development of effective functional foods.

The aim of this study was to investigate whether supplementing branched-chain amino acids (AA) (BCAA) along with a reduced-protein diet increases piglet growth, and whether elevated feed intake and muscle growth-promoting effect contribute to this improvement. In Expt 1, twenty-eight weanling piglets were randomly fed one of the following four diets: a positive control (PC) diet, a reduced-protein negative control (NC) diet, an NC diet supplemented with BCAA to the same levels as in the PC diet (test 1 (T1)) and an NC diet supplemented with a 2-fold dose of BCAA in T1 diet (test 2 (T2)) for 28 d. In Expt 2, twenty-one weanling piglets were randomly assigned to NC, T1 and pair-fed T1 (P) groups. NC and T1 diets were the same as in Expt 1, whereas piglets in the P group were individually pair-fed with the NC group. In Expt 1, the NC group had reduced piglet growth and feed intake compared with the PC group, which were restored in T1 and T2 groups, but no differences were detected between T1 and T2 groups. In Expt 2, T1 and P groups showed increases in growth and mass of some muscles compared with the NC group. Increased feed intake after BCAA supplementation was associated with increased mRNA expressions of agouti-related peptide and co-express neuropeptide Y (NPY) and phosphorylation of mammalian target of rapamycin (mTOR) and ribosomal protein S6 kinase 1 (S6K1), as well as decreased mRNA expressions of melanocortin-4 receptor and cocaine- and amphetamine-regulated transcript and phosphorylation of eukaryotic initiation factor 2α in the hypothalamus. No differences were observed among PC, T1 and T2 groups except for higher NPY mRNA expression in the T2 group than in the PC group (Expt 1). Phosphorylation of mTOR and S6K1 in muscle was enhanced after BCAA supplementation, which was independent of change in feed intake (Expt 2). In conclusion, supplementing BCAA to reduced-protein diets increases feed intake and muscle mass, and contributes to better growth performance in piglets.

An intervention study showed that promoting water consumption in schoolchildren prevented overweight, but a mechanism linking water consumption to overweight was not substantiated. We investigated whether increased water consumption replaced sugar-containing beverages and whether changes in water or sugar-containing beverages influenced body weight outcomes. In a secondary analysis of the intervention study in Germany, we analysed combined longitudinal data from the intervention and control groups. Body weight and height were measured and beverage consumption was self-reported by a 24-h recall questionnaire at the beginning and end of the school year 2006/2007. The effect of a change in water consumption on change in sugar-containing beverage (soft drinks and juices) consumption, change in BMI (kg/m2) and prevalence of overweight and obesity at follow-up was analysed using regression analyses. Of 3220 enroled children, 1987 children (mean age 8·3 (sd 0·7) years) from thirty-two schools were analysed. Increased water consumption by 1 glass/d was associated with a reduced consumption of sugar-containing beverages by 0·12 glasses/d (95 % CI −0·16, −0·08) but was not associated with changes in BMI (P=0·63). Increased consumption of sugar-containing beverages by 1 glass/d was associated with an increased BMI by 0·02 (95 % CI 0·00, 0·03) kg/m2 and increased prevalence of obesity (OR 1·22; 95 % CI 1·04, 1·44) but not with overweight (P=0·83). In conclusion, an increase in water consumption can replace sugar-containing beverages. As sugar-containing beverages were associated with weight gain, this replacement might explain the prevention of obesity through the promotion of water consumption.

Daily breakfast consumption is a common eating behaviour among people who have maintained their weight loss after weight-loss management. However, there is not a precise definition for breakfast in the literature. The purpose of this study was to investigate potential associations between breakfast consumption (based on several definitions) and weight-loss maintenance, as well as to explore differences in breakfast quality between individuals who managed to maintain part of the weight loss and in those who regained weight loss. The study sample consisted of 354 participants of the MedWeight study (age: 32 (sd 10) years, 61 % women) who had lost ≥10 % of their initial body weight and either maintained the loss for ≥1 year (maintainers, n 257) or regained weight loss (regainers, n 97). Participants completed online questionnaires and reported their dietary intake through two telephone 24-h recalls. Breakfast consumption was evaluated using twelve different definitions. The analysis indicated that breakfast consumption was associated with weight-loss maintenance only in men, when using self-reported breakfast consumption or the following breakfast definitions: (1) the first eating episode consumed at home and (2) the first eating episode consumed at home excluding caffeinated drinks. This association remained statistically significant even after adjustment for potential confounding factors. Thus, breakfast, the first eating episode of the day, when consumed at home, may be protective against weight regaining.

A balanced diet informed by sound nutrition knowledge is key for operational readiness and the health of military personnel. Unfortunately, research suggests that military personnel have inadequate dietary intakes. This study assessed general nutrition knowledge, diet quality and their association in Australian military personnel. A convenience sample of male military personnel (n 211) including Army soldiers and officers completed a validated general nutrition knowledge questionnaire (GNKQ) and FFQ. The GNKQ assessed knowledge of dietary guidelines (Section A), sources of nutrients (Section B), choosing everyday foods (Section C) and diet–disease relationships (Section D). The Australian Recommended Food Score (ARFS) was used to assess diet quality from FFQ data. Statistical analyses included the χ2 test, Spearman’s correlation test, t test, median test, ANCOVA and ordinal logistic regression. The mean total GNKQ score was 52·7 %. Participants performed best on Section A (58·5 %) followed by Sections B (57·3 %) and C (57·0 %) and worst on Section D (31·0 %). Overall, officers scored significantly higher than soldiers (58·7 v. 51·9 %, P=0·001). Age was weakly but positively correlated with GNKQ total scores (r 0·307; P<0·0005), with no significant effects seen for level of education (P=0·463) or living arrangement (P=0·167). Overall ARFS was 37·6 (sd 7·7) (50·8 %) with officers scoring significantly higher than soldiers (54·7 v. 50·3 %, P=0·040). No demographic variables influenced total ARFS. The total GNKQ score had a significant, positive but weak relationship with total ARFS (r 0·179; P=0·009). Given the importance of nutrition to personnel health and operational readiness, initiatives to improve nutrition knowledge and diet quality are recommended in this population, especially in soldiers.

Initial successful weight loss is often followed by weight regain after the dietary intervention. Compared with lean people, cellular stress in adipose tissue is increased in obese subjects. However, the relation between cellular stress and the risk for weight regain after weight loss is unclear. Therefore, we determined the expression levels of stress proteins during weight loss and weight maintenance in relation to weight regain. In vivo findings were compared with results from in vitro cultured human Simpson–Golabi–Behmel syndrome (SGBS) adipocytes. In total, eighteen healthy subjects underwent an 8-week diet programme with a 10-month follow-up. Participants were categorised as weight maintainers or weight regainers (WR) depending on their weight changes during the intervention. Abdominal subcutaneous adipose tissue biopsies were obtained before and after the diet and after the follow-up. In vitro differentiated SGBS adipocytes were starved for 96 h with low (0·55 mm) glucose. Levels of stress proteins were determined by Western blotting. WR showed increased expressions of β-actin, calnexin, heat shock protein (HSP) 27, HSP60 and HSP70. Changes of β-actin, HSP27 and HSP70 are linked to HSP60, a proposed key factor in weight regain after weight loss. SGBS adipocytes showed increased levels of β-actin and HSP60 after 96 h of glucose restriction. The increased level of cellular stress proteins in the adipose tissue of WR probably resides in the adipocytes as shown by in vitro experiments. Cellular stress accumulated in adipose tissue during weight loss may be a risk factor for weight regain.

We examined whether there are sex differences in children’s fruit and vegetable (FV) intake and in descriptive norms (i.e. perceived FV intake) related to parents and friends. We also studied whether friends’ impact is as important as that of parents on children’s FV intake. Data from the PRO GREENS project in Finland were obtained from 424 children at the age 11 years at baseline. At baseline, 2009 children filled in a questionnaire about descriptive norms conceptualised as perceived FV intake of their parents and friends. They also filled in a validated FFQ that assessed their FV intake both at baseline and in the follow-up in 2010. The associations were examined with multi-level regression analyses with multi-group comparisons. Girls reported higher perceived FV intake of friends and higher own fruit intake at baseline, compared with boys, and higher vegetable intake both at baseline and in the follow-up. Perceived FV intake of parents and friends was positively associated with both girls’ and boys’ FV intake in both study years. The impact of perceived fruit intake of the mother was stronger among boys. The change in children’s FV intake was affected only by perceived FV intake of father and friends. No large sex differences in descriptive norms were found, but the impact of friends on children’s FV intake can generally be considered as important as that of parents. Future interventions could benefit from taking into account friends’ impact as role models on children’s FV intake.

Both undernutrition and hypoxia exert a negative influence on both growth pattern and bone mechanical properties in developing rats. The present study explored the effects of chronic food restriction on both variables in growing rats exposed to simulated high-altitude hypoxia. Male rats (n 80) aged 28 d were divided into normoxic (Nx) and hypoxic (Hx) groups. Hx rats were exposed to hypobaric air (380 mmHg) in decompression chambers. At T0, Nx and Hx rats were subdivided into four equal subgroups: normoxic control and hypoxic controls, and normoxic growth-restricted and hypoxic growth-restricted received 80 % of the amount of food consumed freely by their respective controls for a 4-week period. Half of these animals were studied at the end of this period (T4). The remaining rats in each group continued under the same environmental conditions, but food was offered ad libitum to explore the type of catch-up growth during 8 weeks. Structural bone properties (strength and stiffness) were evaluated in the right femur midshaft by the mechanical three-point bending test; geometric properties (length, cross-sectional area, cortical mass, bending cross-sectional moment of inertia) and intrinsic properties of the bone tissue (elastic modulus) were measured or derived from appropriate equations. Bone mineralisation was assessed by ash measurement of the left femur. These data indicate that the growth-retarded effects of diminished food intake, induced either by food restriction or hypoxia-related inhibition of appetite, generated the formation of corresponding smaller bones in which subnormal structural and geometric properties were observed. However, they seemed to be appropriate to the body mass of the animals and suggest, therefore, that the bones were not osteopenic. When food restriction was imposed in Hx rats, the combined effects of both variables were additive, inducing a further reduction of bone mass and bone load-carrying capacity. In all cases, the mechanical properties of the mineralised tissue were unaffected. This and the capacity of the treated bones to undergone complete catch-up growth with full restoration of the biomechanical properties suggest that undernutrition, under either Nx or Hx conditions, does not affect bone behaviour because it remains appropriate to its mechanical functions.

High alcohol consumption is an important risk factor for chronic disease and liver degeneration. Paraoxonase (PON1) and arylesterase (AE) are functions of the enzyme paraoxonase, which is synthesised by the liver. Paraoxonase circulates in plasma bound to HDL and hydrolyses lipid peroxides, protecting lipoproteins against oxidative modification. It has been shown that excessive alcohol consumption leads to a reduction of serum PON1 and AE activities; however, studies investigating the association with low and moderate alcohol consumption are scarce. We investigated the cross-sectional association between alcohol consumption and serum activities of PON1 and AE using data from the population-based Bavarian Food Consumption Survey II survey. PON1 and AE activities were quantified in serum samples of 566 male and female study participants (aged 18–80 years), and dietary intake including alcohol consumption was estimated from three 24-h dietary recalls. The association between alcohol consumption and PON1 and AE activities was analysed using linear regression, adjusted for age, sex and socio-economic status. There was no strong association between alcohol consumption and enzymatic activities of PON1 and AE in the Bavarian population. PON1 activity was seen to be lowest in non-drinkers (0 g/d) and highest in people who consumed 15·1–30 g of alcohol/d. AE activity increased across alcohol consumption categories, with a mean maximum difference of 14 U/ml (Pfor linear trend 0·04). These associations were attenuated after adjustment for blood concentrations of HDL. The results of this study do not support the hypothesis that alcohol consumption is related to important alterations in PON1 and AE activities.