We validated doubly-labelled water (DLW) by comparison to indirect calorimetry and food intake–mass balance in eight Labrador dogs (24–32 kg) over 4 d. We used several alternative equations for calculating CO2 production, based on the single- and two-pool models and used two alternative methods for evaluating the elimination constants: two-sample and multiple-sampling. In all cases the DLW technique overestimated the direct estimate of CO2 production. The greatest overestimates occurred with the single-pool model. Using two samples, rather than multiple samples, to derive the elimination constants produced slightly more discrepant results. Discrepancies greatly exceeded the measured analytical precision of the DLW estimates. The higher values with DLW probably occurred because the dogs were extremely active during the 1 h in each 24 spent outside the chamber. Estimates of CO2 production from food intake–mass balance, which include this activity, produced a much closer comparison to DLW (lowest mean discrepancy 0·3 % using the observed group mean dilution space ratio and an assumption that the mass changes reflected changes in hydration for all except one animal). We recommend an equilibration time of 6 h and use of the two-pool model based on the observed population dilution space for future studies of energy demands in dogs of this body mass.

This review summarizes the results of published, randomized clinical trials that have examined the impact of administration of micronutrients, singly or in combination to infants, preschool and school children on linear growth. Supplementation of single micronutrients resulted in small or no benefits on linear growth. A meta-analysis of zinc supplementation trials confirmed that zinc has a significant but small impact (0.22 SD units) on length gain in children 0–13 years of age. however, a recent study reported a substantially greater benefit (>1 sd) in stunted and non-stunted breast-fed infants 6–12 months of age. With iron supplementation, a beneficial effect was found only in anemic children. Vitamin A supplementation trials have reported little or no benefit on linear growth. Data currently available suggest some impact in children with clinical or biochemical vitamin A deficiency, but this issue needs confirmation. Few studies could be identified where a combination of micronutrients was given as a supplement or as fortified food; in the latter set of studies energy availability was assured. The impact on length without multiple micronutrient supplementation was no greater than that observed with single micronutrients. In conclusion, zinc and iron seem to have a modest effect on linear growth in deficient populations. Vitamin A is unlikely to have an important effect on linear growth. Limited available evidence does not allow us to conclude whether a combination of micronutrients, with or without additional food, would have a greater impact than that seen with zinc alone.

The relationship between energy density (ED) of food and drink consumption ad libitum and energy intake (EI) was analysed. EI was taken as average daily EI over the long term, and as EI during a single meal. Moreover, the distribution of EI over three ED categories was analysed. Average daily EI was related to ED of the food and drinks when ED was strongly influenced by specific macronutrients. When ED was strongly influenced by the weight of water, it was not related to EI. During a meal subjects monitored mainly weight, and to a lesser extent, the energy content of the food ingested. Therefore, covertly manipulated ED of a meal affected EI directly. The impact of ED on EI was modulated by dietary behaviours such as restraint. Overt manipulation of ED for 6 months showed that EI was adjusted to a decreased but not to an increased ED in dietary-unrestrained subjects, and that EI was adjusted to an increased but not to a decreased ED in dietary-restrained subjects. Knowledge of ED was shown to lead to an inverse relationship between portion sizes and ED during a meal. Average daily EI consisted of a distribution of EI over the three different categories of ED, so that obese women ate more of foods with a high ED and less of foods with a low ED compared with normal weight women (and nutritional guidelines). In conclusion, ED affected daily EI by means of macronutrient specific effects. EI from a meal with an unknown ED can become inversely related to EI through learning or conditioning. Therefore, the effect of ED on EI during a single meal observation cannot be extrapolated directly to the 24 h effect on EI. With regard to the treatment of obesity, a conscious decreased consumption of foods high in ED and an increase in consumption of low-ED food is necessary to decrease and subsequently maintain body weight, particularly in subjects with a sedentary lifestyle.

This study examined the growth regulatory effects of a phyto-oestrogen, biochanin A, on a transformed human endothelial cell line ECV304 in vitro. Biochanin A was found to inhibit cell proliferation in a dose-dependent fashion and this effect was influenced by the concentration of serum present in the culture medium. In the absence of serum, the calculated IC50 of biochanin A was 0.18 ± 0.1 μM COMPARED TO AN IC50 OF 35±5 Μm at 10 % serum. At low cell density, the growth inhibitory effects of biochanin A were more evident than at high cell density. Co-administration of a synthetic oestrogen diethylstilboestrol with biochanin A did not suppress the growth regulatory effects of biochanin A treatment. We conclude that biochanin A inhibits the cell proliferation of human endothelial cells at concentrations that are physiologically achievable in vivo and that this effect may play an important role in the cancer-preventing activity of the phyto-oestrogens.

The mechanism by which maternal Fe deficiency in the rat causes fetal growth retardation has not been clearly established. This study compared the effects on the fetuses from dams fed a control diet with two groups of dams fed Fe-restricted diets. One Fe-restricted group was fed the Fe-restricted diet for 1 week prior to mating and throughout gestation and the second Fe-restricted group was fed the Fe-restricted diet for 2 weeks prior to mating and throughout gestation. On day 21 of gestation Fe-restricted dams, and their fetuses, were anaemic. Fetal weight was reduced in both Fe-restricted groups compared with controls. Expression of hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) are induced by hypoxia. The levels of HIF-1α mRNA were highest in placenta, then in kidney, heart and liver but were not different between the groups. Levels of plasma VEGF were not different between the groups. Maternal plasma triacylglycerol was decreased in the 1-week Fe-restricted dams compared with controls. Maternal plasma cholesterol and free fatty acid levels were not different between the groups. In fetal plasma, levels of triacylglycerol and cholesterol were decreased in both Fe-restricted groups. In maternal plasma, levels of a number of amino acids were elevated in both Fe-restricted groups. In contrast, levels of a number of amino acids in fetal plasma were lower in both Fe-restricted groups. Fetal plasma lactate was increased in Fe-restricted fetuses but fetal plasma glucose and β-hydroxybutyrate were not affected. These changes in fetal metabolism may contribute to fetal growth retardation in this model. This study does not support the hypothesis that the Fe-restricted fetus is hypoxic.

The present study was performed to further investigate the adaptive component of thermogenesis that appears during prolonged energy restriction. Fifteen obese men and twenty obese women underwent a 15-week weight-loss programme. During this programme, body weight and composition as well as resting energy expenditure (REE) were measured at baseline, after 2 and 8 weeks of energy restriction (-2929 kJ/d) and drug therapy (or placebo), and finally 2–4 weeks after the end of the 15-week drug therapy and energy restriction intervention, when subjects were weight stable. Regression equations were established in a control population of the same age. These equations were then used to predict REE in obese men and women at baseline, after 2 and 8 weeks, as well as after the completion of the programme. In both men and women body weight and fat mass were significantly reduced (P < 0.05 in all cases) while fat-free mass remained unchanged throughout the programme. At baseline, REE predicted from the regression equation was not significantly different from the measured REE in men, while in women the measured REE was 13 % greater than predicted. After 2 weeks of energy restriction, measured REE had fallen by 469 and 635 kJ/d more than predicted and this difference reached 963 and 614 kJ/d by week 8 of treatment in men and women respectively. Once body-weight stability was recovered at the end of the programme, changes in REE remained below predicted changes in men (-622 kJ/d). However, in women changes in predicted and measured REE were no longer different at this time, even if the women were maintaining a reduced body weight. In summary, the present results confirm the existence of adaptive thermogenesis and give objective measurements of this component during weight loss in obese men and women, while they also emphasize that in women this component seems to be essentially explained by the energy restriction.

A food frequency questionnaire (FFQ) and carotenoid database with information on α- and β-carotene, lutein, lycopene and β-cryptoxanthin was prepared and used to compare the carotenoid intakes in five European countries: UK, Republic of Ireland, Spain, France and The Netherlands. Eighty, age- (25–45 years) and sex-matched volunteers were recruited in each of the five countries. A FFQ and carotenoid database was prepared of the most commonly consumed carotenoid rich foods in the participating countries and the information was used to calculate frequency and intake of carotenoid-rich foods. The median total carotenoid intake based on the sum of the five carotenoids, was significantly higher (P<0.05) in France (16.1 mg/day) and lower in Spain (9.5 mg/day,) than the other countries, where the average intake was approximately 14 mg/day. Comparison of dietary source of carotenoids showed that carrots were the major source of β-carotene in all countries except Spain where spinach was most important. Likewise, carrots were also the main source of α-carotene. Tomato or tomato products, were the major source of lycopene. Lutein was mainly obtained from peas in Republic of Ireland and the UK, however, spinach was found to be the major source in other countries. In all countries, β-cryptoxanthin was primarily obtained from citrus fruit. Comparing the data with that from specific European country studies suggests that the FFQ and carotenoid database described in the present paper can be used for comparative dietary intake studies within Europe. The results show that within Europe there are differences in the specific intake of some carotenoids which are related to different foods consumed by people in different countries.

The effects of red pepper and caffeine ingestion on energy and macronutrient balances were examined in eight Caucasian male subjects. All subjects participated in two randomly assigned conditions: control and experimental (red pepper and caffeine). After ingesting a standardized breakfast, subjects ate three meals ad libitum (lunch, dinner and breakfast) and snacks which were served approximately 2 h after the lunch and dinner over a 24 h period. Two appetizers (2×322 kJ with or without 3 g red pepper) were given before lunch and dinner, and a drink (decaffeinated coffee with or without 200 mg caffeine) was served at all meals and snacks except for the after-dinner snack. It is also important to note that on the experimental day, 8.6 and 7.2 g red pepper were also added to lunch and dinner respectively. Red pepper and caffeine consumption significantly reduced the cumulative ad libitum energy intake and increased energy expenditure. The mean difference in energy balance between both conditions was 4000 kJ/d. Moreover, the power spectral analysis of heart rate suggested that this effect of red pepper was associated with an increase in sympathetic:parasympathetic nervous system activity ratio. These results indicate that the consumption of red pepper and caffeine can induce a considerable change in energy balance when individuals are given free access to foods.

Under-reporting of alcohol intake has been frequently reported. However, due to the lack of an objective reference method, e.g. a biomarker, information about the extent of under-reporting of alcohol intake obtained with dietary assessment instruments is not available. The objective of this study was to compare reported alcohol intake data derived from a 24 h recall with a biomarker of recent alcohol intake, the urinary excretion of 5-hydroxytryptophol (5-HTOL):5-hydroxyindole-3-acetic acid (5-HIAA). Embedded into the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study, Germany, a validation study that collected 24 h recall data and 24 h urine samples was conducted. Cohort study participants (n 107) volunteered to participate in this validation study. Among them were five subjects who reported no consumption of alcoholic beverages but had a 5-HTOL:5-HIAA ratio that indicated recent alcohol intake when the clinical cut-off point was taken as a judging criterion. After exclusion of these under-reporters, the Pearson's correlation coefficient between reported alcohol intake and the 5-HTOL:5-HIAA ratio was 0.92 (P<0.0001). Except for low alcohol intake of <0.1 g/kg body mass, a significant increase in 5-HTOL:5-HIAA excretion was observed with increasing amounts of alcohol intake. In conclusion, the 5-HTOL:5-HIAA excretion ratio appears to be a valuable quantitative biomarker of recent alcohol consumption. Denial of alcohol intake can be detected, but for the quantification of under-reporting of alcohol intake 24 h reference data are not yet available. With these data at hand, however, 5-HTOL:5-HIAA could become a biomarker for validation purposes in nutritional epidemiology.

Dietary pattern analysis has recently received growing attention, as it might be more appropriate in studies of diet–disease associations than the single food or nutrient approach that has dominated past epidemiological research. Factor analysis is a technique which is commonly used to identify dietary patterns within study populations. However, the ability of factor solutions to account for variance of food and nutrient intake has so far remained unclear. The present study therefore explored the statistical properties of dietary patterns with regard to the explained variance. Food intake of 8975 men and 13 379 women, assessed by a food-frequency questionnaire, was aggregated into forty-seven separate food groups. Dietary patterns were identified by principal component analysis and subsequent varimax rotation. Seven factors were retained for both men and women, which accounted for about 31 % of the total variance. The explained variance was relatively high (>40 %) for cooked vegetables, sauce, meat, dessert, cake, bread other than wholemeal, raw vegetables, processed meat, high-fat cheese, butter and margarine. Factor scores were used to investigate associations between the factors and nutrient intake. The patterns accounted for relatively large proportions of variance of energy and macronutrient intake, but for less variance of alcohol and micronutrient intake, especially of retinol, β-carotene, vitamin E, Ca and ascorbic acid. In addition, factors were related to age, BMI, physical activity, education, smoking and vitamin and mineral supplement use.

Cognition is a field of thought processes by which an individual processes information through skills of perception, thinking, memory, learning and attention. Zinc deficiency may affect cognitive development by alterations in attention, activity, neuropsychological behavior and motor development. The exact mechanisms are not clear but it appears that zinc is essential for neurogenesis, neuronal migration, synaptogenesis and its deficiency could interfere with neurotransmission and subsequent neuropsychological behavior. Studies in animals show that zinc deficiency during the time of rapid brain growth, or during the juvenile and adolescent period affects cognitive development by decreasing activity, increasing emotional behavior, impairing memory and the capacity to learn. Evidence from human studies is limited. Low maternal intakes of zinc during pregnancy and lactation were found to be associated with less focused attention in neonates and decreased motor functions at 6 months of age. Zinc supplementation resulted in better motor development and more playfulness in low birth weight infants and increased vigorous and functional activity in infants and toddlers. In older school going children the data is controversial but there is some evidence of improved neuropsychological functions with zinc supplementation. Additional research is required to determine the exact biological mechanisms, the critical periods, the threshold of severity and the long-term effects of zinc deprivation on cognitive development.

The validity of 7 d weighed records of diet obtained for pre-menopausal Mexican women was assessed by two independent methods: the energy intake:BMR (EI:BMR) and the dietary N:urinary N (DN:UN). For the latter, complete urine collections are required and completeness was assessed from measurements of para-aminobenzoic acid (PABA) excretion. There were forty-six adult female subjects in the study, thirty-four were from Mexico City and twelve were from a rural population in the Central Highlands, Mexico. However, data were rejected from five urban women for whom the PABA excretion data suggested incomplete urine collection on four or more days. BMR was measured with Oxylog portable O2 consumption meters, and physical activity level was assessed from a self-completed activity diary. An approximate relationship between the EI:BMR ratio and the DN:UN ratio suggested that the rejection limits on the EI:BMR ratio recommended by are wider than the limits on the DN:UN ratio recommended by . Using the recommended cut-off points for EI:BMR but wider limits for DN:UN, twenty-one and twenty-five women respectively had acceptable intake records by the two methods, and sixteen of them by both methods. In conclusion the modification of the DN:UN limits to 0.92 and 1.70 to set acceptable intake values makes the use of measurements of N and energy balance comparable. Urine values with PABA recoveries greater than 100±15 % should be rejected, as should UN values validated by less than 3 d.

Variations in energy balance, body composition, and nutrient partitioning induced by high-fat feeding, cold exposure or by concomitant high-fat feeding and cold exposure were studied in young Wistar rats. Changes in hepatic metabolism as well as in serum free triiodothyronine and leptin levels were also evaluated. Rats were exposed to either 24 or 4°C and fed either a low- or high-fat diet (10 % or 50 % energy respectively) for 2 weeks. Relative to low-fat feeding at 24°C, both energy intake and expenditure were increased by high-fat feeding or by cold exposure, and these changes were accompanied by increased serum triiodothyronine levels. In response to concomitant high-fat feeding and cold exposure, serum triiodothyronine tended to be further elevated, but no further increases in energy intake or energy expenditure were observed. Independently of diet, the increased energy expenditure in cold-exposed rats was not completely balanced by adaptive hyperphagia, with consequential reductions in protein and fat gain, accompanied by marked decreases in serum leptin. Furthermore, unlike high-fat feeding at 24°C, cold exposure enhanced hepatic mitochondrial oxidative capacity both in the low-fat- and high-fat-fed groups. It is concluded that in this strain of young Wistar rats, despite similarly marked stimulation of energy expenditure by high-fat feeding at 24°C, by cold exposure and by concomitant high-fat feeding and cold exposure, an increased hepatic oxidative capacity occurred only in the presence of the cold stimulus.

The effects of ambient temperature (T; 12–29°C), body weight (BW; 30–90 kg) and metabolisable energy intake (ME) on components of energy balance were studied in seven groups of Piétrain × Large White barrows kept in a respiratory chamber. In Expt 1 (groups 1, 2 and 3), T varied in a cyclic way from 22°C to 12°C and then from 12°C to 22°C with three or four consecutive days at each of 22, 19, 16, 14 and 12°C. Similarly, in Expt 2 (groups 4, 5 and 6), T varied from 19 to 29°C and then from 29 to 19°C with three or four consecutive days at each of 19, 22, 25, 27 and 29°C. In both experiments, pigs were offered feed ad libitum. In Expt 3, pigs (group 7) were exposed to the thermic conditions of Expt 1 but their feed allowance was adjusted on a BW basis to the ad libitum intake recorded at 19 and 22°C in Expt 1. Groups 1, 2, 4, 5 and 7 were used over two successive cycles with initial average BW of 37 kg at cycle 1 (four pigs per group) and 63 kg at cycle 2 (three pigs per group). Groups 3 and 6 were studied at an intermediary stage of growth; their initial BW was 45 kg. The O2 and CO2 concentrations, physical activity and feed intake were continuously and simultaneously measured and used to calculate total heat production (HP; HPtot), HP due to physical activity (HPact), activity-free HP (HP0), and thermic effect of feed. HP was modelled as a non-linear function with T, BW and ME as predictors. Results indicate that all components of HP were proportional to BW0·60. Physical activity was minimal between 19 and 27°C (8 % ME). The estimated lower critical temperature was 24°C. Between 24 and 12°C, total thermic effect of feed decreased from 31 to 16 % ME, but the short-term thermic effect of feed (5·1 % ME) remained constant. Equations for prediction of HPtot, HPact and HP0 according to BW, T and ME are proposed and evaluated according to literature values; values for the feed cost of thermoregulation in pigs are proposed.

The purpose of the present study was to describe the longitudinal development of nutrient intake and to determine the stability of this intake from adolescence into adulthood. Longitudinal data of the Amsterdam Growth and Health Longitudinal Study were analysed; the dietary intake of 200 subjects (males and females) was repeatedly measured (eight times) over a period of 20 years, covering the age period of 13–33 years. Dietary intake was determined with the detailed crosscheck dietary history interview. With use of multivariate ANOVA for repeated measurements, trends in macro- and micronutrients over time and differences between genders were analysed. Furthermore, stability coefficients, corrected for time-dependent (biological age) and time-independent covariates (gender) were calculated, taking into account all the measurements. The results showed significant (P<0.001) time and gender effects for energy intake (kJ) and the following macronutrients: protein (g and % total energy supply), fat (g) and carbohydrate (g). Interaction effects between time and gender diminished when the macronutrients were calculated as a percentage of total energy intake. The micronutrients Ca, Fe and vitamins changed significantly (P<0.001) over time and showed an interaction effect with gender, with the exception of cholesterol intake (mg/MJ), which did not show an interaction effect of time and gender. The tracking of the nutrient intake showed relatively low but significant (P<0.05) stability coefficients for all macro- and micronutrients (0.28–0.52). In conclusion, dietary intake does change considerably over time, with the exception of polyunsaturated fat intake (% total energy supply) for both males and females and fat intake in females. Furthermore, stability coefficients for nutrients appeared to be low to moderate. Although these coefficients may be somewhat attenuated as a result of the relatively large measurement error of the dietary intake measurement, they suggest moderate stability of diet over time. These findings may imply that dietary intake is changeable and suggest that disease prevention measures can be implemented in adulthood.

An 8 week feeding trial was conducted to determine the dietary K requirement for juvenile hybrid tilapia (Oreochromis niloticus × O. aureus). Purified diets with eight levels (0, 1, 2, 3, 4, 5, 7, 10 g/kg diet) of supplemental K were fed to tilapia. Each diet was fed to three replicate groups of fish initially weighing a mean value of 0.77 (SE 0.01) g/fish in a closed, recirculating rearing system. Weight gain was higher (P<0.05) in fish fed the diets supplemented with 2, 3 and 4 g K/kg diet than in fish fed diet with 10 g K/kg diet and the unsupplemented control diet. Gill Na+-K+ ATPase activity was highest in fish fed the diets supplemented with 1–3 g K/kg diet, followed by fish fed the diet with 5 g K/kg diet and lowest in fish fed the diet with 10 g K/kg diet. Whole-body K content in fish were generally increased as the dietary K supplementation level increased. Analysis by polynomial regression of weight gain and gill Na+-K+ ATPase activity and by linear regression of whole-body K retention of the fish indicated that the adequate dietary K concentration for tilapia is about 2–3 g/kg diet.

Fractured neck of femur occurs mostly in the older female population and is generally caused by falls. Malnutrition has been postulated as a factor that increases the tendency to suffer falls. Nutritional status of older female hospital patients admitted for emergency surgery for fractured neck of femur recruited (n 75), was compared with an age-matched independent-living group of females attending one of three local day centres (n 50). Dietary assessment was undertaken using three consecutive 24 h dietary recalls and, in the hip fracture group, completed menu cards were used as memory prompts. Data concerning key lifestyle characteristics were obtained using a face-to-face administered questionnaire. Blood samples were taken to determine levels of plasma albumin, transferrin, C-reactive protein (CRP), cholesterol, vitamin C, Se, Zn and total antioxidant status. Haemolysate samples were analysed for Se-dependent glutathione peroxidase activity. There were no significant differences in age between the two groups, but the hip fracture patients had lower mean values for body weight (59.6 v. 67.5 kg; p = 0.005), mindex (weight/demispan) (83· v. 94.4 kg/m; P < 0·0001), calculated BMI (24·1 v. 27·5 kg/m2P<0·0001), mid-upper arm circumference; 27·1 v. 31·3 cm, p = 0.001) and triceps skinfold thickness; 17·0 v. 18.9 mm, p = 0·005) than the home-living group. The hip fracture patients had lower intakes of energy (4·3 v. 5·4 MJ, p = 0·001), fat (p = 0·025), carbohydrate (p = 0·002), protein (p = 0·006), thiamine (p = 0·017), vitamin B6 (p = 0·001), calcium (p = 0·01), K (p = 0·001), Mg (p = 0·001), P (p = 0·001), Fe (p = 0·007), Se (p = 0·008) and NSP (p = 0·001). Mean intakes of both groups were below the estimated average requirement for energy and below the reference nutrient intakes for folate, Ca, vitamin D, Mg, K, Se and Zn. In a high percentage of the hip fracture group the dietary intake of particular nutrients fell below the lower reference nutrient intake for Se (73 %), Mg (54 %) and Fe (19 %). As expected, the fracture patients had reduced plasma albumin (P<0·0001) and increased CRP (P<0·001) values. They had higher plasma vitamin C levels (P<0·001) and lower cholesterol levels (p = 0.04) than the day centre attendees. There were no significant differences in plasma levels of Se, Zn, transferrin or haemolysate glutathione peroxidase activity between the two groups. However, there was evidence of under-nutrition in both groups as key anthropometric values were low, plasma nutrient and metabolite levels were below the standard reference ranges and many individuals had low dietary intakes for specified nutrients.

Earlier studies show that in iron deficiency with anaemia and in latent iron deficiency neurotransmitters are altered. The changes induced in the fetal brain are irreversible on rehabilitation. The important alterations in glutamate metabolism in latent iron deficiency stimulated studies on gamma aminobutyric acid and glutaminate receptors. It was observed that binding of 3H-muscimol at pH 7.5 and 1 mg protein/assay increased significantly in synaptic vesicular membranes and under similar conditions 3H-glutamate binding showed reduction. Thus iron deficiency played a role in both excitatory and inhibitory neurotransmitter receptors. To elucidate the role of body iron status on the brain, anaemic children with thalassemia and iron deficiency were subjected to ‘magnetic resonance spectroscopy’ of globus pallidus, caudate and dentate nuclei and there was no change in iron content. The concentrations of creatinine and aspartate increased, with lowering of choline content. The findings were similar in thalassemia as well as iron deficiency anaemia, suggesting that in anaemia changes operate through reduced oxygen availability.