Food frequency questionnaire and socio-demographic data were collected from over 10000 Scottish men and women aged 40–59 years in a cross-sectional study of coronary heart disease (CHD) risk factors. Dietary intake, including the antioxidant vitamins C and E and β-carotene, was assessed for different socio-economic groups. Trends in nutrient intakes were found with social-class (occupational) groups I–V. The non-manual-manual distinctions were clear even after standardizing for serum cotinine, and alternative classification by housing tenure and level of education did not confound the social-class effect. Total energy intake was significantly higher in the manual (men 10363 KJ, women 7507 KJ) than in the non-manual (men 9156 KJ, women 7169 KJ) groups, and all nutrient amounts except for vitamin C, vitamin E, β-carotene and fiber were significantly higher in the manual than the non-manual groups. Alcohol intake was lower in manual women, but higher in manual men compared with their respective non-manual groups. Sex and social-class differences were maintained after adjusting for total energy. Women in general, and manual women in particular, had the highest percentage energy from total fat (40.2) and saturated fat (18.2), while the percentage energy from polyunsaturated fat was lower in men than women, and lowest in manual men (4.4). The polyunsaturated: saturated fat (P:S) ratios were, for non-manual and manual men 0.32 and 0.31, and for non-manual and manual women 0.31 and 0.28. Fibre and antioxidant vitamin intakes, when expressed as nutrient densities, were lower in men than women, and lowest in manual men. Overall, men and women in manual occupations had a poorer-quality diet than did those in non-manual occupations. The coincident low P:S ratios and low antioxidant vitamin intakes in manual groups may contribute to an increased risk of CHD. Thus, the findings are compatible with the view that poor diet may be a contributory factor to the higher mortality rates for CHD which occur in the lower socio-economic groups.

Body fat content of seven lean women (body mass index (BMI) 20.6 (sd1.8) kg/m2) and seven overweight women (BMI 31.1 (sd 3.3) kg/m2) was estimated by six different methods: underwater weighing (UWW), body-water dilution (BWD), whole-body counting (40K), skinfold thickness (SFT), bio-electrical impedance (BEI) and magnetic resonance imaging (MRI). Using UWW as the reference method, the differences between percentage fat by each other method and the percentage fat by UWW were calculated for each subject. The mean difference was lowest for SFT and highest for BWD. MRI showed the lowest variability in individual results, and 40K the highest. 40K and BWD methods used in combination gave better agreement with UWW results than either 40K or BWD methods alone. There was a weak negative correlation between the difference from the UWW results and percentage fat in the SFT measurements, but not in the BWD, 40K, BEI or MRI measurements, suggesting that for these methods the assumptions involved produced no greater inaccuracy in the overweight women than in the lean women. In all subjects the BEI offered little improvement over the traditional SFT measurements. The agreement between MRI and UWW estimates in both lean and overweight women suggests that MRI may be a satisfactory substitute for the more established methods of body fat estimation in adult women.

The tracer-to-infant deuterium dilution method for the measurement of milk intake was evaluated in twenty breast-fed and twenty formula-fed infants. The isotope method was compared with conventional direct-weighing techniques. Human milk intake was assessed by 5 d test-weighing. Intakes of formula, supplemental foods, and water were determined by pre- and post-weighing of feeding bottles. An oral dose of 200 mg 2H2O/kg body-weight was given to each infant, and urine was sampled daily for 14 d. 2H enrichment of the urine was measured by gas-isotope-ratio mass spectrometry. Milk intakes estimated from the deuterium dilution method were consistently higher than those from direct-weighing; the mean difference between methods was 106 (sd 47) g/d or 14% for the breast-fed group and 70 (sd 155) g/d or 8 % for the formula-fed group. Estimates of intake for some infants varied substantially between the two methods of measurement. When the estimated values of human milk intake were corrected for environmental water influx and insensible water loss during breast-feeding, the relative bias decreased to 5%. Correction of the estimated values of formula intake for environmental water influx decreased the relative bias to 1–2%. The acceptability of the deuterium dilution method to determine milk intake depends on the goals and the tolerance for error in group and individual intake estimates of a given study

The increasing interest in the possible role of antioxidant vitamins in many disease states means that methods of assessing vitamin intakes which are suitable for large-scale investigations are now required. The suitability of the food-frequency questionnaire, which was developed by the Medical Research Council – Cardiff Group, for determining dietary intake of antioxidant vitamins in epidemiological studies was investigated in 196 Scottish men. The validity of the dietary data was assessed by comparison with serum vitamin concentrations, and separate analyses were performed for current smokers and non-smokers. The results showed that total energy intake and the percentage of energy derived from sugar were higher in smokers, and that both dietary and serum values of vitamin C, β-carotene and vitamin E were lower in smokers than non-smokers. After adjustment for serum lipids, energy intake and body mass index, correlation coefficients between dietary and serum vitamins C and E were similar for smokers (r 0.555 and 0.25 respectively) and non-smokers (r 0.58 and 0.32 respectively). Correlation between dietary and serum carotenes was reduced from 0.28 in non-smokers to 0.09 in smokers and correlations for retinol and total vitamin A were weakly significant only for non-smokers. The food-frequency questionnaire assigned > 70% of subjects correctly into the upper or lower plus adjacent tertiles of serum vitamin values, with the exception of β-carotene and total vitamin A for smokers. Thus, the food-frequency questionnaire appeared to be an adequate tool for assigning individuals into tertiles of serum antioxidant vitamins with the main exception of β-carotene for smokers. Marked differences do occur between the vitamins and between the smoking groups which may reflect reduced accuracy of reporting on the food-frequency questionnaire or differential absorption and metabolism of the vitamins.

In order to test whether gastric motility can adapt to changes in nutrient load, gastric emptying of hyperosmotic glucose and protein drinks was measured by applied potential tomography in two groups of ten volunteers following dietary supplementation with 400 g glucose/d for 3 d. The half emptying time for the glucose test meal was significantly faster after the standard diet had been supplemented with glucose compared with the standard diet alone (median and range, 20.7 (4.6–36.8) ν. 29.1 (19.8–38.4) min; P < 0.05), while the emptying of the protein drink (Oxo; Brooke Bond Ltd) was unchanged (median and range, 18.0 (12.5–23.6) ν. 16.1 (9.6–22.7) min). These results suggest that rapid and specific adaptation of the small intestinal regulatory mechanisms for gastric emptying of nutrient solutions can occur in response to increases in dietary load. This adaptation may be explained by desensitization of nutrient receptors or by a reduction in the area of receptor field exposed to nutrients caused by increased absorption of glucose in the upper small intestine

In 1229 subjects, 521 males and 708 females, with a wide range in body mass index (BMI; 13.9–40.9 kg/m2), and an age range of 7–83 years, body composition was determined by densitometry and anthropometry. The relationship between densitometrically-determined body fat percentage (BF%) and BMI, taking age and sex (males =1, females = 0) into account, was analysed. For children aged 15 years and younger, the relationship differed from that in adults, due to the height-related increase in BMI in children. In children the BF% could be predicted by the formula BF% = 1.51xBMI–0.70xage–3.6xsex+1.4 (R2 0.38, SE of estimate (see) 4.4% BF%). In adults the prediction formula was: BF% = 1.20xBMI+0.23xage−10.8xsex–5.4 (R2 0.79, see = 4.1% BF%). Internal and external cross-validation of the prediction formulas showed that they gave valid estimates of body fat in males and females at all ages. In obese subjects however, the prediction formulas slightly overestimated the BF%. The prediction error is comparable to the prediction error obtained with other methods of estimating BF%, such as skinfold thickness measurements or bioelectrical impedance.

The relationship between nutrient intake and pregnancy outcome (adjusted birth weight and gestational age) was investigated in randomly selected non-smokers (n 97) and in heavy smokers (15 + cigarettes/d) (n 72) booking for ante-natal care at a hospital in South London. Weighed dietary intakes (7 d) were obtained at 28 and 36 weeks gestation. Birth weight was adjusted for gestational age, maternal height, parity and sex of infant.

Compared with non-smokers, intakes of micronutrients and fibre were lower in smokers at both 28 and 36 weeks, and smokers reduced their intakes more in late pregnancy. The babies of smokers had a lower adjusted birth weight but there was no difference in length of gestation between smokers and non-smokers. After controlling for smoking, social class and alcohol consumption, nutrient intakes at 28 weeks were found to have no effect on adjusted birth weight. However, intakes of protein, zinc, riboflavin and thiamin at 36 weeks, and the change in intakes of these nutrients (plus iron) between 28 and 36 weeks, had independent positive effects on birth weight. Some of the effect of smoking on birth weight appeared to be mediated through differences in nutrient intakes. Smoking explained 14.3% of the variance in birth weight in this population and a further 2.4–7.2 % was explained by change in nutrient intakes between 28 and 36 weeks. It is recommended that women in pregnancy do not reduce their dietary intakes in late pregnancy.

The total amounts of time spent eating and ruminating per 24 h by goats and sheep were determined. The efficiencies of chewing during eating (<C.EAT>) and chewing during ruminating (<C.RUM>) on the breakdown of feed particles to below the critical size required to leave the rumen (< 1.0 mm) were investigated. All studies were done with the animals fed on a chaffed lucerne (Medicago sativa) hay diet. Goats spent more time eating (+3.1 h; P < 0.01), and less time ruminating (-2.2 h; P < 0.05) per 24 h, than sheep, when fed hourly at ad lib. intake. The efficiency of chewing during eating (<C.EAT>) in breaking down feed particles to < 1.0 mm was greater in goats (85%; P < 0.01) than sheep (48%). The process of rumination in sheep served to reduce the feed particles which were > 1.0 mm in the rumen to < 1.0 mm. Sheep tended to be more efficient in this process than goats (59 ν 48%), with the difference not attaining significance (P > 0.1). The greater frequency of chews (number of total jaw movements/min) during eating in goats (P < 0.01), or during ruminating in sheep (P < 0.001), was the major component explaining differences in efficiency between the two species in both the eating and rumination processes. When corrected for the number of chews/min, the differences in <C.RUM> and <C.EAT> were not significant between goats and sheep. During eating goats had greater apparent rates of total salivary secretion (P < 0.1), and greater apparent rates of salivary nitrogen secretion (P < 0.05) than sheep. The results help explain the greater fibre digestibility and rumen ammonia irreversible loss rates in goats than sheep, when both species were fed on lucerne chaff.

Sprague–Dawley rats (3 weeks old) were fed on isoenergetic diets in which 40 % of the total energy was provided as fat either in the form of butter (high saturated fat), olive oil (high monounsaturated fat) or maize oil (high polyunsaturated fat), with one group on low-fat (10% of total energy) standard diet as a control. Animals were killed after 8.4 (se 0.8) weeks by cardiac puncture. Similar pieces of jejunum and ileum were prepared for morphometric studies. Extracts of tissue from the proximal and distal segments of the whole small intestine from four animals per group were assayed using established techniques for enteroglucagon, motilin, neurotensin, somatostatin, substance P and vasoactive intestinal peptide (VIP). We found that maize oil and olive oil increased villus height: crypt depth ratio in both jejunum and ileum. Maize oil increased tissue concentrations of somatostatin (P < 0.05) and substance P (P < 0.005) in the proximal segment. Both maize oil and olive oil increased tissue concentrations of neurotensin and substance P (P < 0.005) in the distal segments. These observations may explain the improvement of intestinal absorption of fluid following supplementation with polyunsaturated fat

The responses of dwarf mice to dietary administration of clenbuterol (3 mg/kg diet), daily injections of growth hormone (15 μg/mouse per d) or both treatments combined were investigated and their actions, and any interactions, on whole-body growth, composition and protein metabolism, and muscle, liver and heart growth and protein metabolism, were studied at days 0, 4 and 8 of treatment. Growth hormone, with or without clenbuterol, induced an increase in body-weight growth and tail length growth; clenbuterol alone did not affect body-weight or tail length. Both growth hormone and clenbuterol reduced the percentage of whole-body fat and increased the protein:fat ratio. They also increased protein synthesis rates of whole body and muscle, although the magnitude of the increase was greater in response to growth hormone than to clenbuterol. Clenbuterol specifically induced growth of muscle, with a decrease in liver protein content, whereas growth hormone exhibited more general anabolic effects on tissue protein. Previous reports have suggested that effects of clenbuterol on skeletal muscle are mediated, at least in part, via decreased rates of protein degradation; we could find little evidence of any decrease in whole-body or tissue protein degradation and anabolic effects were largely due to increases in protein synthesis rates. However, small increases in muscle protein degradation rate were observed in response to growth hormone. Growth hormone induced a progressive increase in serum insulin-like growth factor-1 concentration, whereas there was no change with clenbuterol administration. Anabolic effects on whole-body and skeletal muscle protein metabolism, therefore, appear to be initially via independent mechanisms but are finally mediated by a common response (increased protein synthesis) in dwarf mice.

Failure to thrive (FTT) in infants with congenital heart disease (CHD) can be attributed to their low energy intakes and high resting energy expenditures. Energy intake, energy expenditure and growth were studied in infants with CHD on normal formula feeds and then on feeds supplemented with glucose polymer to see whether supplementation improved energy retention and growth. Mean gross energy intakes increased by 31.7% on high-energy feeding and mean weight gain improved from 1.3 g/kg per d on control to 5.8 g/kg per d on high-energy feeding. Resting oxygen consumption (νo2 ml/kg per min) was not significantly different on the two feeding regimens, although respiratory quotient rose on high-energy feeding reflecting the increased carbohydrate intake. Estimated energy costs of growth on high-energy feeding fell within the previously described range for normal infants. It is recommended that infants with CHD known to be associated with FTT are fed on high-energy diets from the time of diagnosis in order to optimize growth.

The present work with growing rats was undertaken to study the effect of daily food intake (DFI) on true protein digestibility (TD), and apparent digestibility of dry matter (DM), energy (DE), starch, soluble dietary fibre (SDF) and insoluble dietary fibre (IDF). The design involved two different dietary combinations, barley + rapeseed meal (diet 1) and oats + wheat bran (diet 2). A slight but significantly negative relationship was seen between DFI and TD on diet 1 while no such relationship was found on diet 2. Although significant, DFI influenced DM digestibility of both diets only slightly. A similar situation could also be seen for the effect of DFI on DE. The digestibility of starch was significantly affected by DFI on both diets even though the lowest values were as high as 0.994. SDF digestibility (fermentability) was not influenced by DFI when the rats were given diet 1, while there was a significant negative effect of DFI on digestibility of SDF when diet 2 was given. The digestibility (fermentability) of IDF was not affected by DFI on either of the two diets. The results confirm the existence of a weak negative relationship between DFI and digestibility of a range of nutrients although the effect seems to be only marginal and of no importance under practical feeding conditions

Growing dogs were divided into three groups and were fed on a control (rice) diet, a diet in which cassava (Manihot esculenta Crantz; gari) was used as the carbohydrate source, and the rice diet to which cyanide (equivalent to that present in gari) was added. Each group consumed its diet for 14 weeks, during which plasma thiocyanate concentration and plasma lipase (EC 3.1.1.3) activity were monitored. Plasma free amino acids were determined from pooled samples taken at the end of the experimental period, and the insulin status of the dogs was evaluated using the gluconeogenic index. The dogs were killed and the pancreas examined for histopathology. Dogs fed on both gari diet and the rice+cyanide diet generated significant amounts of thiocyanate when compared with the controls, with the rice+cyanide group having higher plasma thiocyanate than the gari group (P < 0.01). Plasma lipase activity rose significantly at the end of the experimental period in the dogs fed on gari (P < 0.05). Gluconeogenesis from protein was greatest in the dogs fed on gari, five times greater than that in the control dogs, while gluconeogenesis from protein in the dogs fed on rice+cyanide was approximately twice as high as that of the control dogs. Histopathological examination of the pancreas showed haemorrhage, necrosis, fibrosis and atrophy of the acinar tissue and fibrosis of the islets of Langerhans in the dogs fed on gari. The pancreas of the dogs fed on rice+cyanide showed similar lesions but haemorrhage was not prominent and fibrosis was more marked. The present study indicated that a hypoinsulinaemia developed which was more severe in the animals fed on gari than in the dogs fed on the rice+cyanide diet and that the condition was not related to the level of plasma thiocyanate or the histopathology observed.

Growing dogs were divided into three groups and were fed on nutritionally-balanced diets. Control dogs were fed on a rice diet, the cassava (gari) group ate a diet in which gari provided the carbohydrate source, while the rice + cyanide group consumed the rice diet to which hydrocyanic acid (equivalent to that present in gari) was added. Each group consumed its diet for 14 weeks, during which plasma thiocyanate concentration and total serum triiodothyronine (T3) were monitored. At the end of the experiment the concentrations of the plasma free amino acids phenylalanine and tyrosine, the thyroid weights and histology were determined. While plasma thiocyanate remained undetectable in control dogs, animals consuming both gari and rice + cyanide generated significant amounts. In the control dogs and the gari group, total serum T3 increased 40 and 38.8 % respectively from the basal level by the end of the period (P < 0.02). In contrast there was a decrease in T3 by 36% in the dogs fed on rice+cyanide (P < 0.05). This group also showed significant thyroid enlargement and a histological picture consistent with parenchymatous goitre, whereas the gari group was essentially normal. The relatively low mean thyroid weight, the rise in total serum T3 level and the normal histological appearance of the gland indicate that dogs that consumed the gari diet were essentially normal with respect to their thyroid function, in spite of their high blood thiocyanate content. In contrast, dogs that consumed rice with cyanide suffered from hypothyroidism and goitre. It is suggested that the gari diet, despite generating thiocyanate endogenously, when taken in a nutritionally-balanced diet with high-quality animal protein, has no deleterious effects on thyroid function.

Urinary excretion of acid-soluble peptides (ASP) was measured in rats given streptozotocin or dexamethasone. Streptozotocin-induced diabetic rats excreted increased amounts of urinary nitrogen and ASP-form amino acids. The urinary ratio for N: ASP-form leucine plus valine, which has been shown to reflect the efficiency of dietary N utilization, increased in the diabetic rats, suggesting the impaired utilization of dietary N (and re-utilization of endogenous N). Dexamethasone administration to adrenalectomized rats caused increased excretion of urinary ASP-form leucine plus valine with a concomitant increase in N excretion. However, urinary ratio for N: ASP-form leucine plus valine did not change significantly. The results suggested that dexamethasone caused increased degradation of body proteins, but maintained the efficiency of dietary N utilization or re-utilization of endogenous N. Based on the present observations and the hypothesis proposed previously by the present authors (Noguchi et al. 1988) that urinary excretion of ASP-form leucine plus valine reflects the rate of whole-body protein degradation and the urinary ratio for N: ASP-form leucine plus valine represents N utilization, the origin of urinary N in streptozotocin-diabetic and dexamethasone-administered rats is discussed