The prevalence of obesity has increased simultaneously with the increase in the consumption of large food portion sizes (FPS). Studies investigating this association among adolescents are limited; fewer have addressed energy-dense foods as a potential risk factor. In the present study, the association between the portion size of the most energy-dense foods and BMI was investigated. A representative sample of 636 British adolescents (11–18 years) was used from the 2008–2011 UK National Diet and Nutrition Survey. FPS were estimated for the most energy-dense foods (those containing above 10·5 kJ/g (2·5 kcal/g)). Regression models with BMI as the outcome variable were adjusted for age, sex and misreporting energy intake (EI). A positive association was observed between total EI and BMI. For each 418 kJ (100 kcal) increase in EI, BMI increased by 0·19 kg/m2 (95 % CI 0·10, 0·28; P< 0·001) for the whole sample. This association remained significant after stratifying the sample by misreporting. The portion sizes of a limited number of high-energy-dense foods (high-fibre breakfast cereals, cream and high-energy soft drinks (carbonated)) were found to be positively associated with a higher BMI among all adolescents after adjusting for misreporting. When eliminating the effect of under-reporting, larger portion sizes of a number of high-energy-dense foods (biscuits, cheese, cream and cakes) were found to be positively associated with BMI among normal reporters. The portion sizes of only high-fibre breakfast cereals and high-energy soft drinks (carbonated) were found to be positively associated with BMI among under-reporters. These findings emphasise the importance of considering under-reporting when analysing adolescents' dietary intake data. Also, there is a need to address adolescents' awareness of portion sizes of energy-dense foods to improve their food choice and future health outcomes.

In the present study, structural changes in the milk protein α-lactalbumin (α-LA) and its proteolysis were investigated for the potential formation of protein–fatty acid complexes during in vivo gastric digestion. Capsule endoscopy allowed visualisation of the digestion of the test drinks, with nasogastric tubes allowing sampling of the gastric contents. A total of ten healthy volunteers had nasogastric tubes inserted into the stomach and ingested test drinks containing 50 g/l of sucrose and 25 g/l of α-LA with and without 4 g/l of oleic acid (OA). The samples of gastric contents were collected for analysis at 3 min intervals. The results revealed a rapid decrease in the pH of the stomach of the subjects. The fasting pH of 2·31 (sd 1·19) increased to a pH maxima of pH 6·54 (sd 0·29) after ingestion, with a subsequent decrease to pH 2·22 (sd 1·91) after 21 min (n 8). Fluorescence spectroscopy and Fourier transform IR spectroscopy revealed partial protein unfolding, coinciding with the decrease in pH below the isoelectric point of α-LA. The activity of pepsin in the fasting state was found to be 39 (sd 12) units/ml of gastric juice. Rapid digestion of the protein occurred: after 15 min, no native protein was detected using SDS–PAGE; HPLC revealed the presence of small amounts of native protein after 24 min of gastric digestion. Mirocam® capsule endoscopy imaging and video clips (see the online supplementary material) revealed that gastric peristalsis resulted in a heterogeneous mixture during gastric digestion. Unfolding of α-LA was observed during gastric transit; however, there was no evidence of a cytotoxic complex being formed between α-LA and OA.

The maldigestion and malabsorption of fat in infants fed milk formula results due to the minimal production of pancreatic lipase. Thus, to investigate lipid digestion and absorption and mimic the situation in newborns, a young porcine exocrine pancreatic insufficient (EPI) model was adapted and validated in the present study. A total of thirteen EPI pigs, aged 8 weeks old, were randomised into three groups and fed either a milk-based formula or a milk-based formula supplemented with either bacterial or fungal lipase. Digestion and absorption of fat was directly correlated with the addition of lipases as demonstrated by a 30 % increase in the coefficient of fat absorption. In comparison to the control group, a 40 and 25 % reduction in total fat content and 26 and 45 % reduction in n-3 and n-6 fatty acid (FA) content in the stool was observed for lipases 1 and 2, respectively. Improved fat absorption was reflected in the blood levels of lipid parameters. During the experiment, only a very slight gain in body weight was observed in EPI piglets, which can be explained by the absence of pancreatic protease and amylase in the gastrointestinal tract. This is similar to newborn babies that have reduced physiological function of exocrine pancreas. In conclusion, we postulate that the EPI pig model fed with infant formula mimics the growth and lipid digestion and absorption in human neonates and can be used to elucidate further importance of fat and FA in the development and growth of newborns, as well as for testing novel formula compositions.

Casein and whey differ in amino acid composition and in the rate of absorption; however, the absorption rate of casein can be increased to mimic that of whey by exogenous hydrolysis. The objective of the present study was to compare the effects of hydrolysed casein (HC), intact casein (IC) and intact whey (IW) on energy expenditure (EE) and appetite regulation, and thereby to investigate the influence of amino acid composition and the rate of absorption. In the present randomised cross-over study, twenty-four overweight and moderately obese young men and women consumed three isoenergetic dietary treatments that varied in protein source. The study was conducted in a respiration chamber, where EE, substrate oxidation and subjective appetite were measured over 24 h at three independent visits. Moreover, blood and urine samples were collected from the participants. The results showed no differences in 24 h and postprandial EE or appetite regulation. However, lipid oxidation, estimated from the respiratory quotient (RQ), was found to be higher after consumption of IW than after consumption of HC during daytime (P= 0·014) as well as during the time after the breakfast meal (P= 0·008) when the food was provided. Likewise, NEFA concentrations were found to be higher after consumption of IW than after consumption of HC and IC (P< 0·01). However, there was no overall difference in the concentration of insulin or glucagon-like peptide 1. In conclusion, dietary treatments when served as high-protein mixed meals induced similar effects on EE and appetite regulation, except for lipid oxidation, where RQ values suggest that it is higher after consumption of IW than after consumption of HC.

The present meta-analysis of randomised controlled trials (RCT) aimed to investigate the effect of oat intake on glycaemic control and insulin sensitivity. A literature search was carried out in PubMed, ScienceDirect Online and The Cochrane Library (up to October 2013) for RCT that assessed the effect of oat intake on glucose control and insulin sensitivity. A total of fifteen articles with 673 subjects met the inclusion criteria. A random-effects model was used when the overall pooled studies exhibited significant heterogeneity. Otherwise, a fixed-effects model was used. Compared with controls, oat intake significantly reduced the concentrations of fasting insulin by − 6·29 (95 % CI − 12·32, − 0·27) pmol/l (P= 0·04) and the values of glucose AUC (GAUC; 0–120 min) by − 30·23 (95 % CI − 43·65, − 16·81) min × mmol/l (P< 0·0001). There was a slight decrease in fasting glucose concentrations, glycated Hb concentrations and homeostatic model assessment-insulin resistance values in subjects who consumed oats, but the difference was not significant. In conclusion, oat intake significantly lowers fasting insulin concentrations and GAUC values. To further investigate the effect of oat intake on fasting glucose concentrations, additional long-term and high-quality RCT with a parallel design are required.

Without gains in nutritional outcomes, it is unlikely that school feeding programmes (SFP) could improve cognition and academic performance of schoolchildren despite the improvements in school enrolment. We compared the nutrient intake adequacy and Fe and nutritional status of SFP and non-SFP participants in a cross-sectional survey involving 383 schoolchildren (aged 5–13 years). Quantitative 24 h recalls and weighed food records, repeated in 20 % subsample, were used to estimate energy and nutrient intakes adjusted for day-to-day variations. The probability of adequacy (PA) was calculated for selected micronutrients and the mean of all PA (MPA) was calculated. The concentrations of Hb, serum ferritin, and soluble transferrin receptor (sTfR) and anthropometric measurements were used to determine Fe and nutritional status. Energy and nutrient intakes and their adequacies were significantly higher among SFP participants (P< 0·001). The MPA of micronutrients was significantly higher among SFP participants (0·61 v. 0·18; P< 0·001), and the multiple-micronutrient-fortified corn soya blend was a key contributor to micronutrient adequacy. In SFP participants, 6 g/l higher Hb concentrations (P< 0·001) and about 10 % points lower anaemia prevalence (P= 0·06) were observed. The concentration of sTfR was significantly lower among SFP participants (11·2 v. 124 mg/l; P= 0·04); however, there was no difference in the prevalence of Fe deficiency and Fe-deficiency anaemia between SFP and non-SFP participants. There was also no significant difference in the prevalence of thinness, underweight and stunting. In conclusion, the present results indicate that school feeding is associated with higher intakes and adequacies of energy and nutrients, but not with the prevalence of Fe and nutritional status indicators. The results also indicate an important role for micronutrient-dense foods in the achievement of micronutrient adequacy within SFP.

Previous studies have suggested that long-chain n-3 fatty acids derived from seafood are associated with a lower risk of mortality, CHD and stroke. Whether α-linolenic acid (ALA, 18 : 3n-3), a plant-derived long-chain essential n-3 fatty acid, is associated with a lower risk of these outcomes is unclear. The aim of the present study was to examine the associations of plasma phospholipid and dietary ALA with the risk of mortality, CHD and stroke among older adults who participated in the Cardiovascular Health Study, a cohort study of adults aged ≥ 65 years. A total of 2709 participants were included in the plasma phospholipid ALA analysis and 2583 participants were included in the dietary ALA analysis. Cox regression was used to assess the associations of plasma phospholipid and dietary ALA with the risk of mortality, incident CHD and stroke. In minimally and multivariable-adjusted models, plasma phospholipid ALA was found to be not associated with the risk of mortality, incident CHD or stroke. After adjustment for age, sex, race, enrolment site, education, smoking status, diabetes, BMI, alcohol consumption, treated hypertension and total energy intake, higher dietary ALA intake was found to be associated with a lower risk of total and non-cardiovascular mortality; on comparing the highest quintiles of dietary ALA with the lowest quintiles, the HR for total mortality and non-cardiovascular mortality were found to be 0·73 (95 % CI 0·61, 0·88) and 0·64 (95 % CI 0·52, 0·80), respectively. Dietary ALA was found to be not associated with the risk of cardiovascular mortality, incident CHD or stroke. In conclusion, the results of the present suggest study that dietary ALA, but not plasma phospholipid ALA, is associated with a lower risk of total and non-cardiovascular mortality in older adults.

The time course of metabolic and cardiovascular changes with weight gain and subsequent weight loss has not been elucidated. The goal of the present study was to determine how weight gain, weight loss and altered body fat distribution affected metabolic and cardiovascular changes in an obese dog model. Testing was performed when the dogs were lean (scores 4–5 on a nine-point scale), after ad libitum feeding for 12 and 32 weeks to promote obesity (>5 score), and after weight loss. Measurements included serum glucose and insulin, plasma leptin, adiponectin and C-reactive protein, echocardiography, flow-mediated dilation and blood pressure. Body fat distribution was assessed by computed tomography. Fasting serum glucose concentrations increased significantly with obesity (P< 0·05). Heart rate increased by 22 (se 5) bpm after 12 weeks of obesity (P= 0·003). Systolic left ventricular free wall thickness increased after 12 weeks of obesity (P= 0·002), but decreased after weight loss compared with that observed in the lean phase (P= 0·03). Ventricular free wall thickness was more strongly correlated with visceral fat (r 0·6, P= 0·001) than with total body fat (r 0·4, P= 0·03) and was not significantly correlated with subcutaneous body fat (r 0·3, P= 0·1). The present study provides evidence that metabolic and cardiovascular alterations occur within only 12 weeks of obesity in an obese dog model and are strongly predicted by visceral fat. These results emphasise the importance of obesity prevention, as weight loss did not result in the return of all metabolic indicators to their normal levels. Moreover, systolic cardiac muscle thickness was reduced after weight loss compared with the pre-obesity levels, suggesting possible acute adverse cardiovascular effects.

Fruit and vegetables make an important contribution to health, partly due to the composition of phytonutrients, such as carotenoids and polyphenols. The aim of the present study was to quantify the intake of fruit and vegetables across different European countries using food consumption data of increasing complexity: food balance sheets (FBS); the European Food Safety Authority (EFSA) Comprehensive Database; individual food consumption data from the UK National Diet and Nutrition Survey (NDNS). Across Europe, the average consumption of fruit and vegetables ranged from 192 to 824 g/d (FBS data). Based on EFSA data, nine out of fourteen countries consumed < 400 g/d (recommended by the WHO), although even in the highest-consuming countries such as Spain, 36 % did not reach the target intake. In the UK, the average consumption of fruit and vegetables was 310 g/d (NDNS data). Generally, phytonutrient intake increased in accordance with fruit and vegetable intake across all European countries with the exception of lycopene (from tomatoes), which appeared to be higher in some countries that consumed less fruit and vegetables. There were little differences in the average intake of flavanols, flavonols and lycopene in those who did or did not meet the 400 g/d recommendation in the UK. However, average intakes of carotenoid, flavanone, anthocyanidin and ellagic acid were higher in those who consumed >400 g/d of fruit and vegetables compared with those who did not. Overall, intakes of phytonutrients are highly variable, suggesting that while some individuals obtain healthful amounts, there may be others who do not gain all the potential benefits associated with phytonutrients in the diet.

Obesity has become a public health concern due to its positive association with the incidence of many diseases, and coffee components including chlorogenic acid (CGA) and caffeine have been demonstrated to play roles in the suppression of fat accumulation. To investigate the mechanism by which CGA and caffeine regulate lipid metabolism, in the present study, forty mice were randomly assigned to four groups and fed diets containing no CGA or caffeine, CGA, caffeine, or CGA+caffeine for 24 weeks. Body weight, intraperitoneal adipose tissue (IPAT) weight, and serum biochemical parameters were measured, and the activities and mRNA and protein expression of lipid metabolism-related enzymes were analysed. There was a decrease in the body weight and IPAT weight of mice fed the CGA+caffeine diet. There was a significant decrease in the serum and hepatic concentrations of total cholesterol, TAG and leptin of mice fed the CGA+caffeine diet. The activities of carnitine acyltransferase (CAT) and acyl-CoA oxidase (ACO) were increased in mice fed the caffeine and CGA+caffeine diets, while the activity of fatty acid synthase (FAS) was suppressed in those fed the CGA+caffeine diet. The mRNA expression levels of AMP-activated protein kinase (AMPK), CAT and ACO were considerably up-regulated in mice fed the CGA+caffeine diet, while those of PPARγ2 were down-regulated. The protein expression levels of AMPK were increased and those of FAS were decreased in mice fed the CGA+caffeine diet. These results indicate that CGA+caffeine suppresses fat accumulation and body weight gain by regulating the activities and mRNA and protein expression levels of hepatic lipid metabolism-related enzymes and that these effects are stronger than those exerted by CGA and caffeine individually.

Limited evidence suggests that the dietary inclusion of oligofructose, an inulin-type fructan with prebiotic properties, may increase satiety and, thus, reduce energy intake and body weight in overweight and obese adults. The aim of the present study was to assess the effect of oligofructose supplementation for 12 weeks on the BMI of overweight and obese children. A total of ninety-seven children aged 7–18 years who were overweight and obese (BMI >85th percentile) were randomly assigned to receive placebo (maltodextrin) or oligofructose (both at an age-dependent dose: 8 g/d for children aged 7–11 years and 15 g/d for children aged 12–18 years) for 12 weeks. Before the intervention, all children received dietetic advice and they were encouraged to engage in physical activity. The primary outcome measure was the BMI-for-age z-score difference between the groups at the end of the intervention. Data from seventy-nine (81 %) children were available for analysis. At 12 weeks, the BMI-for-age z-score difference did not differ between the experimental (n 40) and control (n 39) groups (mean difference 0·002, 95 % CI − 0·11, 0·1). There were also no significant differences between the groups with regard to any of the secondary outcomes, such as the mean BMI-for-age z-score, percentage of body weight reduction and the difference in total body fat. Adverse effects were similar in both groups. In conclusion, oligofructose supplementation for 12 weeks has no effect on body weight in overweight and obese children.

In the present study, we examined the association between maternal education and unhealthy eating behaviour (the consumption of snack and sugar-sweetened beverages (SSB)) and explored environmental factors that might mediate this association in 11-year-old children. These environmental factors include home availability of snacks and SSB, parental rules about snack and SSB consumption, parental intake of snacks and SSB, peer sensitivity and children's snack-purchasing behaviour. Data were obtained from the fourth wave of the INPACT (IVO Nutrition and Physical Activity Child cohorT) study (2011), in which 1318 parent–child dyads completed a questionnaire. Data were analysed using multivariate regression models. Children of mothers with an intermediate educational level were found to consume more snacks than those of mothers with a high educational level (B= 1·22, P= 0·02). This association was not mediated by environmental factors. Children of mothers with a low educational level were found to consume more SSB than those of mothers with a high educational level (B= 0·63, P< 0·01). The association between maternal educational level and children's SSB consumption was found to be mediated by parental intake of snacks and SSB and home availability of SSB. The home environment seems to be a promising setting for interventions on reducing socio-economic inequalities in children's SSB consumption.