Different dietary interventions have been identified as potential modifiers of adiponectin concentrations, and they may be influenced by lipid intake. We identified studies investigating the effect of dietary lipids (type/amount) on adiponectin concentrations in a systematic review with meta-analysis. A literature search was conducted until July 2013 using databases such as Medline, Embase and Scopus (MeSH terms: ‘adiponectin’, ‘dietary lipid’, ‘randomized controlled trials (RCT)’). Inclusion criteria were RCT in adults analysing adiponectin concentrations with modification of dietary lipids. Among the 4930 studies retrieved, fifty-three fulfilled the inclusion criteria and were grouped as follows: (1) total dietary lipid intake; (2) dietary/supplementary n-3 PUFA; (3) conjugated linoleic acid (CLA) supplementation; (4) other dietary lipid interventions. Diets with a low fat content in comparison to diets with a high-fat content were not associated with positive changes in adiponectin concentrations (twelve studies; pooled estimate of the difference in means: − 0·04 (95 % CI − 0·82, 0·74) μg/ml). A modest increase in adiponectin concentrations with n-3 PUFA supplementation was observed (thirteen studies; 0·27 (95 % CI 0·07, 0·47) μg/ml). Publication bias was found by using Egger's test (P= 0·01) and funnel plot asymmetry. In contrast, CLA supplementation reduced the circulating concentrations of adiponectin compared with unsaturated fat supplementation (seven studies; − 0·74 (95 % CI − 1·38, − 0·10) μg/ml). However, important sources of heterogeneity were found as revealed by the meta-regression analyses of both n-3 PUFA and CLA supplementation. Results of new RCT would be necessary to confirm these findings.

High-protein (HP) diets are effective anti-steatotic treatment options for patients with non-alcoholic fatty liver disease, but whether these diets also decrease steatosis in hyperlipidaemic conditions is not known. The aim of the present study was to determine the effects of a HP diet on hepatic steatosis and inflammation in hyperlipidaemic mice. Hyperlipidaemic male and female APOE2 knock-in (APOE2ki) mice were fed a semi-synthetic low-protein (LP) or HP diet in combination with a low-fat diet or a high-fat diet for 3 weeks. The HP diets reduced hepatic fat and cholesterol concentrations to 40–55 % of those induced by the corresponding LP diets and attenuated hepatic inflammation mildly. The VLDL-associated plasma cholesterol concentrations decreased to 60–80 %, but those of TAG increased 3–4-fold. APOE2-mediated restriction of fat import into the liver did not modify the effects of a HP diet previously observed in wild-type mice. Female APOE2ki mice exhibited a higher expression of lipogenic, cholesterol-synthesising, inflammatory and cell-stress genes than wild-type female or male APOE2ki mice, but a similar response to HP diets. Low Apob expression and unchanged plasma APOB100 concentrations suggest that HP diets increase the plasma concentrations of TAG by slowing their clearance. The decrease in plasma leptin and hepatic fat and glycogen concentrations and the increase in fatty acid-oxidising gene and phosphoenolpyruvate carboxykinase 1 protein expression suggest a HP diet-mediated increase in mitochondrial metabolism. In conclusion, a HP diet reduces hepatic lipid content in dyslipidaemic mice and lowers the activation status of inflammatory cells in the liver.

In the present study, thirty-five Nellore bulls were used to determine the effects of two levels and two sources (organic and inorganic) of Cu supplementation on the oxidative stability of lipids, measured by the thiobarbituric acid-reactive substance (TBARS) test, meat colour and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) enzyme activities. The following treatments were used: (1) control (C) – basal diet without supplementation of Cu (7 mg Cu/kg DM); (2) I10 – basal diet supplemented with 10 mg Cu/kg DM in the form of copper sulphate (inorganic form); (3) I40 – basal diet supplemented with 40 mg Cu/kg DM in the form of copper sulphate; (4) O10 – basal diet supplemented with 10 mg Cu/kg DM in the form of copper proteinate (organic form); (5) O40 – basal diet supplemented with 40 mg Cu/kg DM in the form of copper proteinate. Lipid oxidation was determined in meat samples exposed to display, modified atmosphere (MA) and vacuum packaging (VC) conditions and in liver samples using the TBARS test. These samples were also evaluated for meat discolouration after exposure to air. The activities of SOD and GSH-Px enzymes were determined in liver samples. In display, MA and VC conditions, the TBARS values of samples from animals supplemented with 40 mg Cu/kg DM were lower than those of samples from control animals. There was no effect of treatment on the colour variables (L*, a*, b*). There was also no significant effect of treatment on hepatic TBARS concentrations and GSH-Px activity. Supplementation with Cu at 40 mg/kg, regardless of the source, induced higher hepatic SOD activity compared with the control treatment. In conclusion, Cu supplementation improved the oxidative stability of lipids in samples exposed to display, MA and VC conditions, demonstrating the antioxidant effect of this mineral.

During the last few decades, plant protein ingredients such as soya proteins have replaced fishmeal in the diets of aquacultured species. This may affect the requirement and metabolism of methionine as soya contains less methionine compared with fishmeal. To assess whether methionine limitation affects decarboxylated S-adenosylmethionine availability and polyamine status, in the present study, juvenile Atlantic salmon were fed a methionine-deficient plant protein-based diet or the same diet supplemented with dl-methionine for 8 weeks. The test diets were compared with a fishmeal-based control diet to assess their effects on the growth performance of fish. Methionine limitation reduced growth and protein accretion, but when fish were fed the dl-methionine-supplemented diet their growth and protein accretion equalled those of fish fed the fishmeal-based control diet. Methionine limitation reduced free methionine concentrations in the plasma and muscle, while those in the liver were not affected. S-adenosylmethionine (SAM) concentrations were higher in the liver of fish fed the methionine-deficient diet, while S-adenosylhomocysteine concentrations were not affected. Putrescine concentrations were higher and spermine concentrations were lower in the liver of fish fed the methionine-deficient diet, while the gene expression of SAM decarboxylase (SAMdc) and the rate-limiting enzyme of polyamine synthesis ornithine decarboxylase (ODC) was not affected. Polyamine turnover, as assessed by spermine/spermidine acetyltransferase (SSAT) abundance, activity and gene expression, was not affected by treatment. However, the gene expression of the cytokine TNF-α increased in fish fed the methionine-deficient diet, indicative of stressful conditions in the liver. Even though taurine concentrations in the liver were not affected by treatment, methionine and taurine concentrations in muscle decreased due to methionine deficiency. Concomitantly, liver phospholipid and cholesterol concentrations were reduced, while NEFA concentrations were elevated. In conclusion, methionine deficiency did not increase polyamine turnover through depletion of hepatic SAM, as assessed by SSAT activity and abundance.

The present study investigated the effects of fructo-oligosaccharides (FOS) on the bioavailability of Fe from ferric pyrophosphate (FP), a water-insoluble compound, in Fe-deficient anaemic rats that were subjected to a Hb repletion assay. Male Wistar rats (n 64) were fed adequate or low (8 mg/kg) Fe diets for 15 d followed by 1 or 2 weeks of Fe repletion with diets providing 35 mg Fe/kg as ferrous sulphate (FS), FP or FP that was mixed with 7·5 % FOS in the form of yacon flour or Raftilose P95 (RAF), a purified source of FOS. The effects of FOS were observed within the 1st week of the repletion period. Fe bioavailability was improved by FOS supplementation, as measured by Hb regeneration efficiency and hepatic Fe stores, which were more pronounced in the RAF group. Moreover, RAF supplementation resulted in a higher biological value relative to that of the FP group. FOS supplementation resulted in caecal enlargement, in addition to acidification and Fe species redistribution in the caecal contents relative to the control rats. These effects occurred concomitantly with decreased ferroportin (FPN)-1 expression in the caecal mucosa, which was similar in magnitude to that observed in the FS group. Caecum mucosal morphometry was influenced by FOS supplementation, whereas crypt fission and cell proliferation were highest in the caecum of the RAF group. These results reinforce the effects of FOS as Fe bioavailability enhancers in anaemic rats that are sustained by early changes in their caecal environment (decreased mucosal FPN-1 expression and increased Fe absorbability, crypt fission and cellularity).

The present study was conducted to investigate the effects of dietary fructo-oligosaccharide (FOS) (0, 1, 2 and 3 %) supplementation on the growth performance, haemato-immunological parameters, cultivable autochthonous (non-adherent) intestinal microbiota and stress resistance of common carp (Cyprinus carpio) fry (3·23 (sem 0·14) g). These parameters were measured after feeding the carp fry with the experimental diets for 7 weeks. Dietary FOS supplementation had no significant effects on the growth performance and food intake of carp fry compared with the control treatment. It also had no significant effects on the following haematological parameters: erythrocyte count; leucocyte counts (WBC); haematocrit; Hb; mean corpuscular volume; mean corpuscular Hb content; mean corpuscular Hb concentration. However, WBC and respiratory burst activity were significantly affected by dietary FOS supplementation. Evaluation of the cultivable autochthonous intestinal microbiota revealed a significant increase in the levels of total viable heterotrophic aerobic bacteria and lactic acid bacteria in fish fed diets supplemented with 2 and 3 % FOS. Furthermore, dietary FOS supplementation significantly increased the survival rate and stress resistance of carp fry compared with the control treatment. These results encourage conducting further research on the administration of FOS and other prebiotics in carp fry studies.

The energy-salvaging capacity of the gut microbiota from dietary ingredients has been proposed as a contributing factor for the development of obesity. This knowledge generated interest in the use of non-digestible dietary ingredients such as prebiotics to manipulate host energy homeostasis. In the present study, the in vitro response of obese human faecal microbiota to novel oligosaccharides was investigated. Dextrans of various molecular weights and degrees of branching were fermented with the faecal microbiota of healthy obese adults in pH-controlled batch cultures. Changes in bacterial populations were monitored using fluorescent in situ hybridisation and SCFA concentrations were analysed by HPLC. The rate of gas production and total volume of gas produced were also determined. In general, the novel dextrans and inulin increased the counts of bifidobacteria. Some of the dextrans were able to alter the composition of the obese human microbiota by increasing the counts of Bacteroides–Prevotella and decreasing those of Faecalibacterium prausnitzii and Ruminococcus bromii/R. flavefaciens. Considerable increases in SCFA concentrations were observed in response to all substrates. Gas production rates were similar during the fermentation of all dextrans, but significantly lower than those during the fermentation of inulin. Lower total gas production and shorter time to attain maximal gas production were observed during the fermentation of the linear 1 kDa dextran than during the fermentation of the other dextrans. The efficacy of bifidobacteria to ferment dextrans relied on the molecular weight and not on the degree of branching. In conclusion, there are no differences in the profiles between the obese and lean human faecal fermentations of dextrans.

Plant-derived α-linolenic acid (ALA) may reduce the risk of CVD, possibly by decreasing systemic inflammation and improving endothelial function. In the present study, the effects of a hypoenergetic diet rich in ALA (3·4 g/d) on the biomarkers of systemic inflammation and vascular function were investigated in eighty-one overweight-to-obese patients with metabolic syndrome traits in comparison with a hypoenergetic diet low in ALA (0·9 g/d, control). After a 6-month dietary intervention, there were significant decreases in the serum concentrations of C-reactive protein (CRP), TNF-α, IL-6, soluble intercellular adhesion molecule-1 (sICAM-1), soluble endothelial selectin (sE-selectin) and asymmetric dimethylarginine in both dietary groups. However, no inter-group differences were observed for all these changes. The serum concentration of YKL-40 (human cartilage glycoprotein 39 or chitinase-3-like protein 1) decreased after the ALA diet when compared with the control diet (P< 0·05 for time × treatment interaction). Plasma concentrations of fibrinogen did not significantly change in the two dietary groups. The decreases in the serum concentrations of sICAM-1, sE-selectin, CRP and YKL-40 were significantly correlated with the decreases in body fat mass. In conclusion, the present study indicates that in overweight-to-obese patients with metabolic syndrome traits, both vascular function and inflammation are improved during body-weight loss. The high ALA intake led to a more pronounced reduction in the serum concentration of YKL-40 compared with the intake of the low-ALA control diet, indicating the existence of independent favourable physiological effects of ALA during weight loss.

Folate is essential for fetal development, and its deficiency during gestation causes behavioural deficits in the offspring. The present study investigated its influence during weaning on brain function in the pups of rats that were put on a folate-deficient (FD) diet on postnatal day (PND) 1. Systemic folate deficiency in pups on the FD diet (n 15) was evident from the dramatically lower hepatic folate concentrations (median 23·7, range 8·1–48·4 ng/mg protein) and higher homocysteine concentrations (median 27·7, range 14·7–45·5 pmol/mg protein), respectively, compared with those of pups on the normal diet (ND; n 9) (median 114·5, range 64·5–158·5 ng/mg protein and median 15·5, range 11·6–18·9 pmol/mg protein) on PND 23. Brain folate concentrations although low were similar in pups on the FD diet (median 10·5, range 5·5–24·5 ng/mg protein) and ND (median 11·1, range 7·1–24·2 ng/mg protein). There was a high accumulation of homocysteine in the brain of FD pups, mostly in the hippocampus (median 58·1, range 40·8–99·7 pmol/mg protein) and cerebellum (median 69·1, range 50·8–126·6 pmol/mg protein), indicating metabolic folate deficiency despite normal brain folate concentrations. Developmental deficits or autistic traits were more frequent in the FD group than in the ND group and repetitive self-grooming occurred, on average, three times (range 1–8) v. once (range 0–3) during 5 min, respectively. Long-term memory or spatial learning and set-shifting deficits affected 12 to 62 % of rats in the FD group compared with none in the ND group. Post-weaning folic acid supplementation did not correct these deficits. These observations indicate that folate deficiency during weaning affects postnatal development even when gestational folate supply is normal.

Studies on the associations of dietary Ca and vitamin D intakes with arterial stiffness are scarce. In the present study, these associations were evaluated in Japanese men. Data from a total of 535 eligible men, aged 35–69 years, who participated in the baseline survey of a cohort study in Tokushima Prefecture, Japan, and underwent brachial–ankle pulse wave velocity (ba-PWV) measurements were analysed. ba-PWV is a measure of arterial stiffness and is recognised as a marker of atherosclerotic vascular damage. Information regarding the cohort's lifestyle characteristics including dietary behaviour over the past year was obtained from a structured self-administered questionnaire. Dietary Ca and vitamin D intakes were adjusted for total energy intake using the residual method and divided into quartiles; the highest quartile was used as the reference. General linear models were used to evaluate the associations between dietary Ca and vitamin D intakes and ba-PWV values adjusted for probable covariates. The association between dietary Ca intake and ba-PWV was further evaluated using similar general linear models stratified by dietary vitamin D intake (median or below/above median). Dietary Ca intake was found to be significantly inversely associated with ba-PWV after adjusting for probable covariates (P for trend = 0·020). However, no such association was observed between dietary vitamin D intake and ba-PWV. The inverse association between dietary Ca intake and ba-PWV was striking in subjects with higher dietary vitamin D intake. However, no association was found in subjects with lower dietary vitamin D intake. These results indicate that adequate dietary Ca and vitamin D intakes may be protective against the development of arterial stiffness in Japanese men.

Dietary modification may affect inflammatory processes and protect against chronic disease. In the present study, we examined the relationship between dietary patterns, circulating carotenoid and tocopherol concentrations, and biomarkers of chronic low-grade systemic inflammation in a 10-year longitudinal study of Scottish postmenopausal women. Diet was assessed by FFQ during 1997–2000 (n 3237, mean age 54·8 (sd 2·2) years). Participants (n 2130, mean age 66·0 (sd 2·2) years) returned during 2007–11 for follow-up. Diet was assessed by FFQ (n 1682) and blood was collected for the analysis of serum high-sensitivity C-reactive protein (hs-CRP), IL-6, serum amyloid A, E-selectin, lipid profile and dietary biomarkers (carotenoids, tocopherols and retinol). Dietary pattern and dietary biomarker (serum carotenoid) components were generated by principal components analysis. A past ‘prudent’ dietary pattern predicted serum concentrations of hs-CRP and IL-6 (which decreased across the quintiles of the dietary pattern; P= 0·002 and P= 0·001, respectively; ANCOVA). Contemporary dietary patterns were also associated with inflammatory biomarkers. The concentrations of hs-CRP and IL-6 decreased across the quintiles of the ‘prudent’ dietary pattern (P= 0·030 and P= 0·006, respectively). hs-CRP concentration increased across the quintiles of a ‘meat-dominated’ dietary pattern (P= 0·001). Inflammatory biomarker concentrations decreased markedly across the quintiles of carotenoid component score (P< 0·001 for hs-CRP and IL-6, and P= 0·016 for E-selectin; ANCOVA). Prudent dietary pattern and carotenoid component scores were negatively associated with serum hs-CRP concentration (unstandardised β for prudent component: − 0·053, 95 % CI − 0·102, − 0·003; carotenoid component: − 0·183, 95 % CI − 0·233, − 0·134) independent of study covariates. A prudent dietary pattern (which reflects a diet high in the intakes of fish, yogurt, pulses, rice, pasta and wine, in addition to fruit and vegetable consumption) and a serum carotenoid profile characteristic of a fruit and vegetable-rich diet are associated with lower concentrations of intermediary markers that are indicative of CVD risk reduction.

Sensory liking influences dietary behaviour, but little is known about specifically associated individual profiles. The aim of the present study was to investigate the associations between liking for fat-and-salt and fat-and-sweet sensations and sociodemographic, economic, psychological, lifestyle and health characteristics in a large sample. Individual characteristics and liking scores were collected by a questionnaire among 37 181 French adults. Liking scores were constructed using a validated preference questionnaire. Multinomial logistic regression models were used to assess the associations between liking levels and individual characteristics. In both sexes, subjects belonging to low-level occupational categories (OR 1·39, 95 % CI 1·16, 1·67 in men; OR 1·28, 95 % CI 1·16, 1·41 in women), highly uncontrolled eaters (men: OR 2·90, 95 % CI 2·60, 3·23; women: OR 2·73, 95 % CI 2·27, 3·30) and obese subjects (men: OR 1·45, 95 % CI 1·14, 1·84; women: OR 1·47, 95 % CI 1·29, 1·68) were more likely to have a strong liking for the fat-and-sweet sensation, whereas older individuals (men: OR 0·13, 95 % CI 0·10, 0·16; women: OR 0·11, 95 % CI 0·09, 0·14) and highly cognitive restrainers (men: OR 0·52, 95 % CI 0·44, 0·63; women: OR 0·60, 95 % CI 0·55, 0·66) were less likely to have a strong liking. Regarding liking for the fat-and-salt sensation, the same associations were found and specific relationships were also highlighted: current smokers and heavy drinkers were more likely to strongly prefer the fat-and-salt sensation compared with non-smokers and abstainers or irregular alcohol consumers. The relationship between individual characteristics and a liking for fat sensation provides new and original information that may be useful for a better understanding of the associations between sensory liking and individual behaviour.

Diet is related to many chronic disease conditions such as the metabolic syndrome (MetS). We set out to compare behaviour-related with disease-related patterns and their association with the MetS in a German cross-sectional study. A total of 905 participants of a Northern German cohort (aged 25–82 years) completed a FFQ, underwent anthropometric assessments and provided a blood sample. Dietary patterns were derived by principal component analysis (PCA) and reduced-rank regression (RRR) from forty-two food groups. Components of the MetS were used as response variables for the RRR analysis. Simplified patterns comprising ten food groups were generated. Logistic regression analysis was performed to evaluate the likelihood of having the MetS across the quartiles of simplified pattern scores. We identified two similar dietary patterns derived by PCA and RRR characterised by high intakes of potatoes, various vegetables, red and processed meat, fats, sauce and bouillon. Comparing simplified patterns, an increased RRR pattern score was associated with a higher OR (2·18, 95 % CI 1·25, 3·81) of having the MetS than an increased PCA pattern score (OR 1·92, 95 % CI 1·21, 3·03). Comparing concordant food groups by both dietary pattern methods, a diet high in legumes, beef, processed meat and bouillon was also positively associated with the prevalence of the MetS after adjustment for potential confounders (OR 1·71, 95 % CI 1·04, 2·79). We identified a behaviour-related pattern that was positively associated with the MetS. The application of both dietary pattern methods may be advantageous to obtain information for designing and realising dietary guidelines. Prospective studies are needed to confirm the results.

Although breakfast is associated with more favourable nutrient intake profiles in children, limited data exist on the impact of breakfast on nutrient adequacy and the potential risk of excessive intakes. Accordingly, we assessed differences in nutrient intake and adequacy among breakfast non-consumers, consumers of breakfasts with ready-to-eat cereal (RTEC) and consumers of other types of breakfasts. We used cross-sectional data from 12 281 children and adolescents aged 4–18 years who took part in the nationally representative Canadian Community Health Survey, 2004. Mean nutrient intakes (obtained using a multiple-pass 24 h recall method) were compared among the breakfast groups using covariate-adjusted regression analysis. Usual nutrient intake distributions, generated using the National Cancer Institute method, were used to determine the prevalence of nutrient inadequacy or the potential risk of excessive intakes from food sources alone and from the combination of food plus supplements. Of these Canadian children, 10 % were breakfast non-consumers, 33 % were consumers of RTEC breakfasts and 57 % were consumers of other types of breakfasts. Non-consumption of breakfast increased with age (4–8 years: 2 %; 9–13 years: 9 %; 14–18 years: 18 %). Breakfast consumers had higher covariate-adjusted intakes of energy, many nutrients and fibre, and lower fat intakes. The prevalence of nutrient inadequacy for vitamin D, Ca, Fe and Mg (from food alone or from the combination of food plus supplements) was highest in breakfast non-consumers, intermediate in consumers of other types of breakfasts and lowest in consumers of RTEC breakfast. For vitamin A, P and Zn, breakfast non-consumers had a higher prevalence of nutrient inadequacy than both breakfast groups. The potential risk of excessive nutrient intakes was low in all groups. Efforts to encourage and maintain breakfast consumption in children and adolescents are warranted.

Dietary protein has been shown to increase urinary Ca excretion in randomised controlled trials, and diets high in protein may have detrimental effects on bone health; however, studies examining the relationship between dietary protein and bone health have conflicting results. In the present study, we examined the relationship between dietary protein (total, animal and vegetable protein) and lumbar spine trabecular volumetric bone mineral density (vBMD) among participants enrolled in the Multi-Ethnic Study of Atherosclerosis (n 1658). Protein intake was assessed using a FFQ obtained at baseline examination (2000–2). Lumbar spine vBMD was measured using quantitative computed tomography (2002–5), on average 3 years later. Multivariable linear and robust regression techniques were used to examine the associations between dietary protein and vBMD. Sex and race/ethnicity jointly modified the association of dietary protein with vBMD (P for interaction = 0·03). Among white women, higher vegetable protein intake was associated with higher vBMD (P for trend = 0·03), after adjustment for age, BMI, physical activity, alcohol consumption, current smoking, educational level, hormone therapy use, menopause and additional dietary factors. There were no consistently significant associations for total and animal protein intakes among white women or other sex and racial/ethnic groups. In conclusion, data from the present large, multi-ethnic, population-based study suggest that a higher level of protein intake, when substituted for fat, is not associated with poor bone health. Differences in the relationship between protein source and race/ethnicity of study populations may in part explain the inconsistent findings reported previously.

To determine the prevalence of household food insecurity in New Zealand (NZ), eight food security statements were included in the 1997 National Nutrition Survey of adults. Rasch model analysis was performed to determine whether each food security statement (addressing a food security attribute) was discrete and could be ranked on a unidimensional scale. The NZ model had marginal ‘household’ reliability (0·60–0·66), good item separation (17·20–17·77) and item infit/outfit values between 0·8 and 1·25. Indices could be ranked by level of severity and represent the experience of household food insecurity in NZ. Categories of food security were assigned and used to predict food choice, and energy and nutrient intakes. Compared with fully secure/almost fully secure households, those that were moderately secure or of low security were less likely to consume the recommended daily servings of fruit and vegetables, and more likely to consume fatty meats. Intake of total fat, saturated, monounsaturated and polyunsaturated fat, cholesterol, lactose and vitamin B12 increased with lower levels of food security. Intakes of glucose, fructose and vitamin C were highest in the fully secure/almost fully secure category. This unique eight-component food security measurement tool has less respondent burden than the US Core Food Security Measure. The relationships between the level of food insecurity and food choice and nutrient intakes illustrate that the most food-insecure households have less healthy diets. This relatively brief population-specific measurement tool is suitable to monitor population food security status, and is a useful marker of nutritional status.

The present study evaluated the effect of different levels of energy restriction on metabolic parameters in obese ponies. Relative weight changes, markers of lipid metabolism and oxidant/antioxidant balance were monitored. A total of eighteen obese (body condition score ≥ 7/9) Shetland ponies were studied over a 23·5-week trial, which was divided into three periods. The first period involved a 4-week adaptation period in which each animal was fed 100 % of their maintenance energy requirements needed to maintain a stable obese body weight (MERob). This was followed by a 16·5-week weight-loss period in which ponies were assigned to receive either 100 % (control group, CONTROL), 80 % (slow weight-loss (SLOW) group) or 60 % (rapid weight-loss (RAPID) group) of their MERob. During the 3-week end-phase period, all ponies were again fed 100 % of their MERob. Relative weight loss was higher in the RAPID group (P< 0·001) compared with the SLOW group. No linear relationship was found as a doubling of the percentage of energy restriction was accompanied by a tripling of the percentage of weight loss. Relative weight gain afterwards in the end-phase period was higher in the RAPID group (P< 0·001) compared with the SLOW and CONTROL groups. During the weight-loss period, TAG and NEFA concentrations were highest in the RAPID group, as were α-tocopherol and ferric-reducing ability of plasma concentrations. After 8 weeks of weight loss, the concentrations of advanced oxidation protein products were higher in the RAPID group compared with the SLOW and CONTROL groups (P< 0·001). In conclusion, the level of energy restriction influences the extent of changes in oxidant/antioxidant balance. Practically, more severe energy restriction regimens may be associated with a greater regain of weight after the restriction period.

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.