Consumption of fish or fish oils rich in the n-3 long chain PUFA EPA and DHA may improve multiple risk factors for CVD. The objective of this study was to determine whether regular consumption of foods enriched with n-3 long-chain PUFA can improve n-3 long-chain PUFA status (erythrocytes) and cardiovascular health. Overweight volunteers with high levels of triacylglycerols (TG; >1·6 mmol/l) were enrolled in a 6-month dietary intervention trial conducted in Adelaide (n 47) and Perth (n 39), and randomised to consume control foods or n-3-enriched foods to achieve an EPA + DHA intake of 1 g/d. Test foods were substituted for equivalent foods in their regular diet. Erythrocyte fatty acids, plasma TG and other CVD risk factors were monitored at 0, 3 and 6 months. There were no significant differences between groups for blood pressure, arterial compliance, glucose, insulin, lipids, C-reactive protein (CRP) or urinary 11-dehydro-thromboxane B2 (TXB2) over 6 months, even though regular consumption of n-3-enriched foods increased EPA + DHA intake from 0·2 to 1·0 g/d. However, the n-3 long-chain PUFA content of erythrocytes increased by 35 and 53 % at 3 and 6 months, respectively, in subjects consuming the n-3-enriched foods. These increases were positively associated with measures of arterial compliance and negatively associated with serum CRP and urinary 11-dehydro-TXB2 excretion. Sustainable increases in dietary intakes and erythrocyte levels of n-3 long-chain PUFA can be achieved through regular consumption of suitably enriched processed foods. Such increases may be associated with reduced CV risk.

The objective of the study was to investigate the ability of an NMR-based metabonomic approach, applied to biofluids, to explore and identify overall exogenous and endogenous biochemical effects of a short-time high intake of milk protein or meat protein given to prepubertal children, the aim being to compare relative differences and not an absolute quantification. A total of twenty-four 8-year-old boys were asked to take 53 g protein as milk (n 12) or meat daily (n 12). At baseline and after 7 d, urine and serum samples were collected and high-resolution 1H NMR spectra were acquired on these using a 800 MHz spectrometer. The milk diet reduced the urinary excretion of hippurate, while the meat diet increased the urinary excretion of creatine, histidine and urea. The NMR measurements on serum revealed minor changes in the lipid profile, which most probably should be ascribed to an increase in the content of SCFA in the blood after consumption of the milk diet. The meat diet had no effect on the metabolic profile of serum. The study for the first time demonstrates the capability of proton NMR-based metabonomics to identify the overall biochemical effects of consumption of different animal proteins. The urine metabolite profile is more susceptible to perturbations as a result of short diet interventions than the serum metabolite profile. The milk diet-induced reduction in urinary excretion of hippurate suggests alterations in gut microflora, which may be useful information for further studies elucidating the effects of bioactive components in milk.

The vitamin B6 status of high school students and its relationship with dietary intake were investigated in this cross-sectional study by face-to-face interview. A total of 157 healthy students aged 16–18 years (eighty-three boys and seventy-four girls) were randomly recruited from two out of nineteen senior high schools in Tainan, Taiwan. Vitamin B6 intakes were calculated from three 24-h dietary records. Direct and indirect vitamin B6 status indicators were measured in plasma, erythrocytes and urine. The anthropometric data, being similar to those of the first Nutrition and Health Survey in Taiwan (1993–1996), showed the normal growth and development of these students. All students except one girl (28·7 nmol/l) had plasma pyridoxal-5′-phosphate (PLP) levels >35 nmol/l, indicating an adequate vitamin B6 status. The mean dietary vitamin B6 intakes of boys and girls were 1·04 (sd 0·29) and 0·96 (sd 0·27) mg/d, respectively. Vitamin B6 status indicators, including plasma PLP, erythrocyte alanine aminotransferase activity coefficient (EALT-AC), aspartate aminotransferase activity coefficient (EAST-AC) and urinary 4-pyridoxic acid (4-PA), were correlated with vitamin B6 intake. Students with adequate values of plasma PLP (>35 nmol/l), EALT-AC ( < 1·25), EAST-AC ( < 1·8) and urinary 4-PA (>3·0 μmol/d) had median intakes of 1·08 and 1·01 mg/d, respectively, for boys and girls. This study suggests that vitamin B6 requirements for boys and girls aged 16–18 years were approximately 1·1 and 1·0 mg/d, respectively.

Siraitia grosvenori Swingle (SG) is a traditional Chinese fruit used as a folk medicine. Its extract (SG-ex) contains potent sweet elements with a sweetness several hundred times higher than table sugar. We investigated the antidiabetic effect of SG-ex in the type 2 diabetic Goto–Kakizaki (GK) rat. Diabetic 7-week-old GK rats were fed a diet supplemented with 0·4 % of the SG-ex for 13 weeks, and its antidiabetic effects were evaluated. SG-ex had no effect on food intake or body weight. In oral glucose tolerance tests (OGTT), SG-ex supplementation improved the insulin response at 15 min (control, 63 (sem 6) pm; SG-ex, 107 (sem 20) pm; P < 0·05) and reduced the plasma glucose level at 120 min after the glucose administration (control, 18·5 (sem 0·8) mm; SG-ex, 14·8 (sem 0·7) mm; P < 0·05). The total amount of insulin in whole pancreas taken from fasting rats was higher in the SG-ex-supplemented group, which may explain the greater capacity to secrete insulin during the OGTT. Thiobarbituric acid-reactive substances in both the liver and the plasma were lower in the SG-ex-supplemented group, suggesting that an absorbable component in SG-ex has an antioxidative effect on lipid peroxidation, thereby counteracting the oxidative stress caused by a diabetic state. Excreted urine volume and urinary albumin level for 24 h were both reduced in the SG-ex-supplemented group, suggesting the attenuation of kidney damage that is caused by diabetes. These data indicate that SG-ex supplementation may prevent complications and attenuate pathological conditions for type 2 diabetes, along with its sweet characteristics.

Yacon roots have been considered a functional food due to the high levels of fructans they contains. In the present study, Ca and Mg balance, bone mass and strength, and caecum mucosal morphometry were evaluated. Growing male Wistar rats (n 24) were fed ad libitum control diets or diets supplemented with yacon flour (5 or 7·5 % fructooligosaccharides) for 27 d. Mineral balance was evaluated in three periods of 5 d (starting on the 4th, 10th and 16th days). After the rats were killled, the bones were removed and bone mineral density was measured. Ca analyses were performed on left femurs and tibias and biomechanical testing on right femurs. The caecum was removed and tissue samples were collected for histological analysis. Caecal histology changed noticeably in rats fed yacon flour: there was an increase in the depth and number of total and bifurcated crypts as well. Yacon flour consumption significantly (P < 0·05) resulted in a positive Ca and Mg balance, leading to higher values of bone mineral retention and biomechanical properties (peak load and stiffness) when compared to the control group. The positive effects on mineral intestinal absorption, bone mass and biomechanical properties showed an important role of yacon roots in the maintenance of healthy bones. The increased number of bifurcating crypts might be related to the higher mineral absorption caused by the enlargement of the absorbing surface in the large intestine of the animals.

The general consensus is that brain serotonin (5-HT) inhibits feed intake in teleost fishes and other vertebrates. Dietary manipulations with the 5-HT precursor tryptophan (TRP) have, however, yielded contradictory effects on feed intake, while studies of the endocrine response to stress indicate that the effects of TRP-enriched feed are context dependent. A characteristic behavioural response to stress is a reduction in feed intake, and in the present study we investigated whether pre-treatment with TRP-enriched feed affected stress-induced changes in feeding behaviour in brown trout (Salmo trutta). After acclimatisation in observation aquaria, isolated fish were fed control or TRP-supplemented feed for 7 d, whereupon they were transferred to a novel environment, in which all fish were fed control feed. Transfer to a new environment resulted in decreased feeding in both the TRP pre-treated and the control-treated group. However, this decrease was more pronounced in the control-treated group. Previous experiments have concluded that stimulation of brain 5-HT systems by TRP enhancement does not affect feed intake in salmonid fishes, but in these studies food intake was observed in unstressed animals only. The present study suggests that pre-treatment with dietary TRP attenuates stress-induced anorexia. Hence, it appears that the effect of dietary manipulations of TRP on feeding behaviour is dependent on the stress levels experienced by experimental animals. These behavioural data are discussed in the context of the involvement of 5-HT in appetite regulation.

Low glycaemic index (GI) diets may facilitate weight loss via behavioural and/or endocrine mechanisms. This study investigated whether the outcomes of the Weight Watchers POINTS® Weight-Loss System could be improved by encouraging dieters to select low GI, high-carbohydrate foods. Ninety-six women (age 20–72 years; BMI 25–40 kg/m2) were recruited as they started the Weight Watchers POINTS® programme for 12 weeks. Weekly classes were randomized so that seven (forty-five women) followed the regular programme while seven others (fifty-one women) followed a revised programme encouraging the selection of low GI foods. Anthropometric and biochemical parameters were measured before and after the 12-week diets. Participants rated hunger and desire to eat using visual analogue scales on 1 d per week, several times per d. Attrition was the same in both groups (32 v. 30 %), as well as many benefits (5 % weight loss, decreases in insulinaemia and blood lipids, waist and hip circumferences, blood pressure). Hunger and desire to eat were rated consistently lower in the low GI group over the 12-week diet. Group differences in subjective sensations were especially large in the afternoon. The 12-week weight management yielded many significant anthropometric and biochemical benefits that were not improved by encouraging dieters to select low GI foods. The subjective benefits (lower hunger and desire to eat) of the low GI diet may be a worthwhile contribution to the motivation of dieters that might affect adherence to the diet over the long term.

Waist circumference (WC) is a measure of central adiposity related to elevated risk factor levels in children and adolescents. The aim of the present study was to describe WC percentiles in 7- to 10-year-old Brazilian children and to compare frequencies of obesity and overweight as defined by BMI and frequencies of excess and at risk of abdominal adiposity as defined by WC to the corresponding age and sex data from British references. A representative sample of 2919 schoolchildren of the city of Florianopolis (southern Brazil) was examined. Smoothed WC percentiles were derived using the least mean square method. Frequencies of overweight and obesity and of excess and at risk of abdominal adiposity were assessed using the 91st and 98th centiles of the British references as cut-off points. WC increased with age in both boys and girls, with higher values for boys at every age and percentile level. Nutritional status categories of children assessed by the 91st and 98th British BMI and WC centiles showed moderate agreement (weighted κ = 0·58). Overweight was more frequent in Brazilian than British children: 15·1 % of girls and 20·1 % of boys were above the 91st percentile of the 1990 BMI for age British references. About one-quarter (22·0 % of girls and 26·9 % of boys) exceeded the 91st percentile of WC British references. The present data could be used to compare WC in children in other populations and may serve as a baseline for future studies of temporal trends in WC in Brazil.