1. Complete 24 h energy and nitrogen balances were measured for fifteen subjects at three levels of energy intake and for two other subjects at two levels of intake.

2. At each level, the fifteen subjects ate diets consisting of fifteen to twenty separate foods for 7 or 8 d. Faeces and urine were collected for the final 4 d. Respiratory gas exchange was measured during the final 72 h while the subjects stayed in an 11 m3 open-circuit respiration chamber, and simulated office or light household work. The energy balance of the other two subjects was determined initially in a similar way when they consumed a diet which was sufficient for energy equilibrium. Subsequently, the measurements were repeated twice at the same high level of metabolizable energy (ME) intake after 4 and 18 d on that diet.

3. Neither energy nor N digestibilities were significantly affected by intake level or subject. Due to relatively small urinary energy losses the ME content of the gross energy increased slightly at the higher intake.

4. Respiratory quotient increased with intake level from 0.78 to 0.87.

5. The efficiencies of utilization of ME were approximately 1.0 for maintenance (from the low to the intermediate intake level) and decreased to about 0.9 for maintenance and energy deposition (from the intermediate to the high intake level).

6. Estimates of daily ME requirements at energy equilibrium were 149 (SD 13) kJ ME/kg body-weight, 432 (SD 33) kJ ME/kg body-weight0.75 and 204 (SD 22) kJ/kg lean body mass. The former two values were negatively correlated with percentage body fat although not significantly so.

7. ME utilization and heat production of the other two subjects were nearly equal after 6 and 20 d on a diet supplying 1.5–1.7 times the ME needed for energy equilibrium.

1. Thirty-three drugs known to stimulate the sympathetic nervous system have been screened for thermogenic properties. The results presented are for seven of them.

2. The drugs were tested in five animal models of obesity (genetic (mice and rats), hypothalamic (mice) and dietary (mice and rats)) as well asin leanmice. Energy-balance studies were undertaken using thecomparative-carcass technique as well as by measurement of daily oxygen consumption.

3. All seven drugs in obese animals tended to reduce body-weight and fat without loss of body protein: they acted by increasing metabolic rate without increasing food intake. They were much less effective in lean animals. These findings lend support to the concept that obesity is due to a diminished activity of the sympathetic nervous system.

4. Differences in the effectiveness of the drugs are discussed in relation to differences between the animal models of obesity. Ephedrine and tranylcypromine were found to be the most effective drugs in this series of experiments and a prima facie case is made for human clinical trials.

1. The prevalence of visual defects, especially from causes associated with nutritional deficiencies, and their relation to diarrhoea in rural Bangladesh have been studied. A trained physician and a team of health workers examined visual defects in 149 villages, with a total population of 182976.

2. According to WHO classification, night blindness (XN) was found in only 0.03 persons/1000 population and 0.04 were found to have conjunctival xerosis (XIA) and Bitot's spot (XIB). Corneal xerosis (X2, X3A, X3B) also was found in 0.04 persons/1000. Night blindness combined with conjunctival xerosis and Bitot's spot (XN + XIA + XIB) was present in 1.69 persons/1000 and all combined stages of active xerophthalmia were seen in 0.06 persons/1000. Xerophthalmia prevailed up to age 19 years. Males had a significantly higher (2.9) incidence/1000 than did females (1.2).

3. The total rate of keratomalacial scar for all ages was 0.31 persons/1000, while corneal opacity from other causes was seen in 2.25 persons/1000 population.

4. More than 2.06 persons/1000 had ocular manifestations of one or more vitamin A deficiencies, while 4.47 persons/1000 had other ocular diseases, except for cataracts.

5. Only 12.0% of all the corneal scars (XS) were due to keratomalacia.

6. History of night blindness is a good indicator of vitamin A deficiency. In 96% of cases, night blindness was associated with conjunctival xerosis and Bitot's spot (XN + XIA + XIB).

7. The onset of approximately 86% of cases of corneal xerosis (X2, X3A, X3B) and night blindness associated with conjunctival xerosis and Bitot's spot (XN + XIA + XIB) was related to diarrhoea.

1. The possibility that viscous polysaccharides, such as guar gum, could lower post-prandial blood glucose levels in part by restricting carbohydrate solutions to a smaller area of small intestine was investigated in twenty healthy human volunteers.

2. Addition of guar gum (22.5 g/l) delayed the mouth-to-caecum transit time of a hypotonic lactulose drink, but did not affect gastric emptying.

3. When a 250 ml solution containing 50 g glucose was confined to a 550 mm length of intestine by an occluding balloon attached to an intestinal tube, maximum blood glucose response was significantly reduced (P < 0.05) though only by 0.9 mmol/l.

4. Addition of guar gum (36 g/l) had no effect on the distribution of a radio-labelled glucose drink (250 ml; 200 g glucose/l) in the small intestine, monitored using a gamma camera, although it significantly delayed gastric emptying (t½ (min): guar gum v. control 115 (SE 15) v. 73 (SE 8)).

5. Reduced contact area is unlikely to be one of the mechanisms by which guar gum improves glucose tolerance.

1. Twenty-nine patients who had suffered from essential hypertension for an average of 8 years, all receiving long-term medication for hypertension, were subject to therapy with vegan food for 1 year. In almost all cases medication was withdrawn or drastically reduced. There was a significant decrease in systolic and diastolic blood pressure. A number of reported symptoms disappeared.

2. There was a significant improvement in a number of clinical variables as well as a significant change in various biochemical indices such as urea, haptoglobin, cholesterol and triglyceride concentrations in blood.

3. Subjectively all patients reported improvement.

4. Selected patients, with a fear of side-effects of medication, who are interested in alternative health care might replace conventional medication with this dietary regimen.

1. A 45 d metabolic study was carried out in four young adult male North American residents consuming a controlled diet based on an amino acid mixture. During the initial 10 d, total daily selenium intake was adjusted to 107.7 (SE 0.1) μg/d, which was reduced to 11.4 (SE 0.1) μg/d for the remaining 35 d.

2. Two doses of a stable isotope (74SeO32-) were administered orally in the post-absorptive state on days 4 and 39 of the study.

3. Se balance (faecal + urinary excretion) as well as stable isotope excretion studies were carried out for the entire 45 d period; blood plasma and erythrocyte Se concentrations were also monitored.

4. Plasma Se concentrations (μg/ml) fell progressively from the initial value of 0.132 (SE 0.007) to 0.083 (SE 0.008) at the end of the study. The erythrocyte concentrations of Se did not vary in a consistent manner (average value for the entire study 0.147 (SE 0.002) μg/ml).

5. Faecal excretion of unenriched Se decreased from 66 (SE 6) μg/d for days 1–10 to 10.2 (SE 0.8) μg/d for days 14–40. Mean urinary excretions of the unenriched Se were 43.9 (SE 2.8) μg/d (days 1–10) and 26.9 (SE 4.6) μg/d (days 14–40). Total balance (intake - faecal excretion - urinary excretion) for unenriched Se was μg/d):-18 (SE 7) days 10–19, -17 (SE 2) days 19–39, -5 (SE 1) days 38–45.

6. Fractional absorption of the ingested label was 0.529 (SE 0.032) and 0.542 (SE 0.038) for the Se-adequate and Se-restricted phases of the study. However, urinary excretion of the absorbed label was reduced from 6.57 (SE 0.73)% for day 1 of the Se-adequate phase to only 3.32 (SE 0.26)% for day 1 of the Se-restricted phase. Similar observations were also made for day 7 of each phase.

7. These findings indicate that immediate contribution of ingested Se to the urinary Se pool is small.

1. Pregnant rats were given control (46 mg iron/kg, 61 mg zinc/kg), low-Zn (6.9 mg Zn/kg) or low-Zn plus Fe (168 mg Fe/kg) diets from day 1 of pregnancy. The animals were allowed to give birth and parturition times recorded. Exactly 24 h after the end of parturition the pups were killed and analysed for water, fat, protein, Fe and Zn contents and the mothers' haemoglobin (Hb) and packed cell volume (PCV) were measured.

2. There were no differences in weight gain or food intakes throughout pregnancy. Parturition times were similar (mean time 123 (SE 15) min) and there were no differences in the number of pups born. Protein, water and fat contents of the pups were similar but the low-Zn Fe-supplemented group had higher pup Fe than the low-Zn unsupplemented group, and the control group had higher pup Zn than both the low-Zn groups. The low-Zn groups had a greater incidence of haemorrhaged or deformed pups, or both, than the controls.

3. Pregnant rats were given diets of adequate Zn level (40 mg/kg) but with varying Fe:Zn (0.8, 1.7, 2.9, 3.7). Zn retention from the diet was measured using 65Zn as an extrinsic label on days 3, 10 and 17 of pregnancy with a whole-body gamma-counter. A group of non-pregnant rats was also included as controls. The 65Zn content of mothers and pups was measured 24–48 h after birth and at 14, 21 and 24 d of age.

4. In all groups Zn retention was highest from the first meal, fell in the second meal and then rose in the third meal of the pregnant but not the non-pregnant rats. There were no differences between the groups given diets of varying Fe:Zn level. Approximately 25% of the 65Zn was transferred from the mothers to the pups by the time they were 48 h old, and a further 17% during the first 14 d of lactation. The pup 65Zn content did not significantly increase after the first 20 d of lactation but the maternal 65Zn level continued to fall gradually.

1. The dietary intake of pregnant Asian women (that is originating from the Indian subcontinent) attending Sorrento Maternity Hospital in Birmingham was determined, using the weighed and recall techniques, at five-weekly intervals from 18 to 38 weeks of pregnancy.

2. Mean energy intake of the group was 7.1 MJ (1700 kcal)/d. The intakes of most nutrients were substantially below those consumed by pregnant European women in Britain, a little below those of expectant Pakistani mothers in Islamabad, and about the same as those of expectant East London mothers. Intakes of vitamin D, total folate, vitamin B6, zinc and magnesium were particularly low.

3. These observations suggest that a number of Asian women in Birmingham are likely to experience nutritional stress in pregnancy, and there is some anthropometric and biochemical evidence from Sorrento, published elsewhere (Bissenden et al. 1981), to support this.

4. A possibly beneficial feature of the diet was a low sodium intake (2 g/d). Previous work at this hospital has noted a lower prevalence of hypertension in pregnant Asian women (Wharton et al. 1980; Bissenden et al. 1981).

1. This report explores the characteristics that influenced median intakes of energy and ten nutrients in a representative sample of 1055 adolescents (11–16 years) in Tasmania, Australia.

2. Among girls, the characteristic with greatest influence on intakes was different for different nutrients. Thus, median intakes of fat, iron, thiamin and niacin-equivalent were lower in heavier, fatter girls. Girls from larger families consumed more riboflavin, while girls with poorly educated mothers consumed less vitamin A. Girls who regularly took vitamin supplements had higher median intakes of (food-derived) calcium.

3. Among boys the increase of intakes of energy and nutrients with age overshadowed the influence of other characteristics.

4. Among younger boys the characteristic with greatest influence varied. Those with highly educated fathers had lower median intakes of energy and carbohydrate; those who exercised vigorously consumed more fat; those who smoked ‘heavily’ (> 10 cigarettes in the previous week) consumed more thiamin and niacin-equivalent.

5. Among older boys the characteristic with greatest influence varied. Those who drank ‘heavily’ (> five glasses in the previous week) had higher intakes of energy and fat. Those from professional–managerial households consumed more thiamin.

6. For vitamin C, there was no sex difference in intakes. Social status had the greatest influence, with children from professional–managerial households eating more.

7. Food choices underlying these differences in energy and nutrient intakes were explored.

1. Three methods of measuring changes in body fat were compared in seventeen patients undergoing a 2-week course of intravenous nutrition. Patients received all nutrition intraveneously at a steady rate of infusion, calculated to supply energy at a rate equal to 1.5 times the resting metabolic expenditure measured before feeding. Fat change was estimated from measurements of skinfold thickness, by isotopic methods (neutron-activation analysis and dilution of tritiated water) and by daily analysis of expired gases.

2. The mean (with 1 SEM) gain in fat over the 2-week period was 1.14 (0.30) kg for skinfold measurement, 0.53 (0.62) kg for isotopic determination and 1.29 (0.22) kg for expired-gas analysis. There were no significant differences between the mean gains in fat measured by the three methods.

3. The results show that expired-gas analysis is the most sensitive technique, measuring change in fat content with an estimated precision of 0.26 kg. The isotopic method is less sensitive, with a precision of 2.38 kg, but provides a detailed description of body composition. In contrast to these highly-specialized techniques, both of which have limited application, the simple technique of measurement of skinfolds occupies an intermediate position of sensitivity, with a precision for measuring change in fat content of 0.85 kg, and also has the potential to measure total body fat content.

1. The previous paper (Eaton et al. 1984) described the nutrient intake of pregnant Asian women attending Sorrento Maternity Hospital, Birmingham using the weighed and recall methods. The present paper describes the subethnic variation in nutrient intake by comparing the results from Pakistanis, Sikhs, Hindus and Bangladeshis and also describes food eaten by the pregnant women.

2. Generally. Sikhs had the highest intake of most nutrients (mean energy 7.5 MJ (1800 kcal)/d) and the greatest variety of foods; they ate chapatti and paratha but few ate meat. Hindus had a very similar diet but more ate meat, chicken and rice. Pakistanis had an energy intake about 10% below that of the Sikhs and Hindus; meat was eaten, and intake of fruit, and therefore vitamin C, was quite large. Bangladeshis were the smallest women; they had the lowest intake of energy (mean energy 6.5 MJ (1555 kcal)/d) and most nutrients, except for protein, so that 15% of energy was provided by protein. Fish, rice and a low-fat intake were other features of their diet.

3. From a nutritional standpoint, peoples coming from the Asian subcontinent should be divided into subethnic groups; the collective term ‘Asian’ is insufficient.

4. It is not clear whether these differences have any effect on the life and health of the individuals. Comparison of groups does not suggest an obvious relationship between dietary intake and fetal growth; however, there is other evidence to implicate the possible role of deficiencies of protein, energy, zinc and pyridoxine.

5. The results provide some support for the community nutritional policies of (a) offering vitamin D supplements to all pregnant Asian women and (b) fortifying bread with calcium, thiamin and nicotinic acid. There is probably no need to offer vitamin A and C supplements but they are harmless. Indications for iron supplementation are no different from those for white English women.

1. The onset of cold-induced thermogenesis was studied in a strain of mice which produced among their offspring genetically-obese (ob/ob) individuals. A thermogenic response was present in a majority by day 5 after birth.

2. The thermogenic response to cold was measured on days 5, 10 or 15 after birth, and the animals reared and the onset of obesity noted. The correlation between the subsequent development of obesity and a poor thermogenic response in early life was low.

3. A poor thermogenic response at day 15 was associated with the presence in brown adipocytes of mitochondria with disordered internal structures.

4. At day 42 both non-obese and obviously-obese mice showed a similar thermogenic response to moderate cold exposure.

5. It would seem that in this strain of mice disordered internal mitochondria1 structure in brown adipose tissue is associated with a poor thermogenic response to cold, but not invariably with the subsequent onset of obesity.

1. Two groups of patients with non-insulin-dependent diabetes mellitus (NIDDM), with dietary advice randomized between a low-carbohydrate (LC) diet and a modified-fat (MF) diet, were followed to determine the effect of diet on phospholipid fatty acid composition of platelets and on development of retinopathy in the 7 years following diagnosis. There was a tendency for retinopathy to occur more frequently in those randomiEd to the LC diet. This difference was not statistically significant, and fatty acid composition of platelets did not differ significantly in those with and without retinopathy.

2. Linoleic acid values from platelet phospholipid fatty acids were significantly higher in NIDDM on an MF diet compared with an LC diet.

3. There was no difference between the two dietary subgroups with respect to platelet arachidonic acid, but this was lower in the whole diabetic population when compared with non-diabetics.

4. The arachidonic acid values correlated with neither glycosylated haemoglobin nor mean glycaemia.

5. Significant correlation between the fatty acid values for platelets and plasma cholesterol esters was found only for 16:0.

1. Rat pups were artificially reared (AR) from postnatal day 4 or 5 till day 20 or 21, by fitting them with gastric cannulas through which milk-substitutes could be infused automatically.

2. Three milk-substitutes were compared: milk M, the usual diet for AR studies, which was somewhat low in protein and very high in carbohydrate; milk A, which resembled rats' milk much more closely in composition; and milk isoM, which was based on the high-energy milk M but was made isoenergetic with milk A. Pups given these diets were termet ARM, ARA and ARisoM respectively. Siblings of the AR rats were left with their mothers to form a mother-reared (MR) control group. Rats were autopsied at 20 or 21 d.

3. Growth in body-weight of all groups of AR pups lagged behind that of their MR siblings for about the first week of AR, but the ARM group showed complete catch-up and the ARA group partial catch-up in body-weight during the second week. ARisoM rats were growth-retarded throughout.

4. Inspection of organ weights expressed relative to body-weight revealed disturbances of organ growth in all AR groups compared with MR animals. ARM rats showed excessive epididymal fat pad and liver weights, but deficits in gastrocnemius muscle, heart and adrenal weights. In contrast, ARA rats usually displayed increased spleen and stomach weights, but lower weight of interscapular brown adipose tissue. ARisoM rats had high brain, liver and stomach weights and low muscle and spleen weights relative to body-weight. All AR groups had elongated small intestines.

5. Hence the patterns of abnormal organ growth differed between groups. Those shown by the ARM and ARisoM groups seemed the more seriously abnormal. The diet approximating the composition of rats' milk (milk A) appears, as intended, to be an improved milk-substitute.

1. Male Wistar rats (approximately 200 g) were given fibre-free semi-synthetic diets containing either sucrose (S) or a sucrose-starch mixture (SS) as the carbohydrate component, or a diet similar to SS containing 40 g guar gum/kg (G), or 100 g cellulose/kg (C). The animals remained healthy, and weight gain after 30 d was similar in all groups.

2. The small intestines of the animals given diet G were significantly longer than those of the other groups, and showed signs of increased mitotic activity and mucosal growth.

3. No significant differences in mucosal enzyme activity were detected between the two fibre-free control groups. Lactase (EC 3.2.1.23) and alkaline phosphatase (EC 3.1.3.1) activities were significantly lower than controls in group G, but were higher in group C.

4. Kinetic analysis of 3-O-methyl glucose uptake by isolated intestine indicated that the maximum transport rate (Vmax) of tissue from group G tended to be lower than from the fibre-free group SS and group C.

5. It is concluded that materials which are classed as dietary fibre but which differ markedly in their physical properties may also differ in the functional changes to which they give rise in the small intestine. These changes may be at least partially mediated by effects on mucosal cell proliferation.

1. Eight young men of normal weight were maintained for 1 week on a weight-maintenance diet followed by a 1-week period of over-feeding with extra fat designed to increase energy intake by 50%. Two 36 h calorimetry sessions with low and high physical activities were included in each feeding period. Faecal and urine collections permitted checks on energy malabsorption and nitrogen excretion.

2. Over-feeding led to increases in body-weight, faecal energy and N excretion and in estimated N retention. Faecal energy outputs on the maintenance and over-feeding diets were 5 and 4.4% of the respective gross energy intakes.

3. Energy expenditure on fat over-feeding increased by 5.6% on the low-activity regimen and 6.4% on the high-activity regimen. This amounted, in terms of the extra energy intake, to 9 and 11 % on the inactive and active schedules respectively. The increase affected day- and night-time rates of energy expenditure plus the basal metabolic rate. Individuals with a low percentage body fat showed the greatest response to over-feeding.

4. Nutrient-balance studies derived from calorimetry suggested that fat over-feeding led to substantial fat deposition with no evidence of sparing of carbohydrate oxidation. The theoretical cost of depositing dietary fat was exceeded, suggesting that regulatory thermogenic mechanisms may have been stimulated to a small extent.

1. Four pigs initially of 30 kg live weight were surgically prepared with two re-entrant cannulas in the jejunum 1.0 m apart which allowed an isolated loop to be formed through which solutions were perfused. 51Cr-EDTA was used as a marker for measuring net secretion or absorption.

2. A new Ringer solution was made, the ionic content of which resembled more closely that found in the jejunum of pigs given similar diets, than Krebs-Ringer solution.

3. The absorption of glucose and water from Krebs-Ringer and new Ringer solutions was compared.

4. The effect of guar gum on the absorption of glucose and water from solutions of glucose and maltose was studied.

5. There was a trend (not significant) for greater absorption of glucose and water from the new Ringer solution than from the Κ rebs-Ringer solution.

6. Guar gum significantly reduced the net absorption of glucose from glucose or maltose solutions from 74.2 to 41.4% (P < 0.001) and 71.1 to 35.0% (P < 0.001) respectively.

7. Guar gum significantly reduced the net absorption of water from the glucose solution from 42.7 to 8.3% (P < 0.01) and from the maltose solution from 49.2 to 5.1% (P < 0.001).

8. The lack of differences between the absorption of glucose from solutions of glucose or maltose suggested that maltase (EC 3.2.1.20) activity was not inhibited to the extent that this limited the rate of glucose absorption.