1. A comparison was made of the effect of a fibre-free diet and diets containing non-digestible polysaccharides on rat caecal and colonic physiology and microflora.

2. All polysaccharide-containing diets led to enlargement of the caecum and colon, associated with increased weight of contents, and of tissue. Carboxymethylcellulose (CMC) had the most marked effect and animals given this also had watery faeces.

3. The density of bacteria in the caecum and colon varied significantly with diet and the proportion of aerobic bacteria in the flora was increased by the CMC diet.

4. In vitro, CMC and hydroxypropylmethylcellulose were poorly fermented.

5. There was a high correlation (caecum r 0.93; colon r 0.94) between tissue weight and wet weight of organ contents but no correlation with bacterial density, number of bacteria per organ, moisture content or short-chain fatty acid content.

6. It is concluded that caecal and colonic enlargement is due to tissue hypertrophy in response to increased bulk of contents, irrespective of the nature of that bulk which varies with diet; it is unlikely that short-chain fatty acids or other microbial metabolites are the stimulus for the trophic response seen when non-digestible dietary polysaccharides are fed to rats.

1. The vitamin A content of human liver tissue was determined in 363 autopsy samples. The sample comprised a total of 181 subjects dying after accidents and 182 dying from coronary heart disease among Singapore ethnic groups of both sexes.

2. The medium vitamin A reserve was 146 mg/kg in accident victims and 141 mg/kg in those who had died of coronary heart disease. Of all the samples 16% contained less than 40 mg/kg, 45% had 100–300 mg/kg, while 9% contained more than 500 mg/kg liver.

3. Among the accident victims, Indians had the lowest median liver vitamin A reserve (118 mg/kg) compared with that in other ethnic groups (137 mg/kg in Chinese, 191 mg/kg in Malays, 155 mg/kg in Caucasians).

4. The ethnic distribution of vitamin A reserve in coronary deaths was similar to that in accident victims.

5. There was no significant difference between the sexes in hepatic vitamin A reserve.

6. The distribution of vitamin A reserve in all the groups was skewed to the right.

1. Eight healthy male volunteers (aged 22–39 years) supplemented their normal daily diet with 15 g encapsulated fish oil (MaxEPA) for a 6 week period. Fasting blood samples were taken before, at the completion of and 3 months after the period of supplementation.

2. Evaluation of nutrient intakes showed that the intake of n-3 polyunsaturated fatty acids rose significantly (P < 0·01) during supplementation. This was reflected in changes in the fatty acid composition of platelet phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE) without any changes in phosphatidyl serine, phosphatidyl inositol or sphingomyelin.

3. In both PC and PE there were significant (P < 0·05) increases in the levels of 18:1 n-9 and 20:5n-3 fatty acids and a significant (P < 0·05) decrease in 20:4n-6 during supplementation. 16:0 rose significantly in PC (P < 0·05) while in PE, 18:0 fell and both 22:5n-3 and 22:6n-3 rose significantly (P < 0·05).

4. There were no significant effects of fish-oil supplementation on serum lipids, platelet cholesterol: phospholipid, collagen-induced platelet aggregation or collagen-induced platelet thromboxane B2 production. However, there was a significant correlation (P < 0·001; r+0·63) between total phospholipid arachidonic acid and platelet thromboxane production.

5. The fluorescent probe 1,6-diphenyl-1,3,5-hexatriene was used to determine whether fish-oil supplementation altered fluorescence polarization of isolated platelet plasma membrane and, by inference, platelet plasma membrane fluidity. No significant effect of fish-oil supplementation on fluorescence polarization was seen.

1. Male Wistar rats (approximately 200 g) were given distilled water and a semi-synthetic control diet for 6 d. On day 7, 37 kBq 65Zn were administered intramuscularly and the rats were given distilled water, beer, cider, red wine, whisky or ethanol as their only source of fluid. The wine, whisky and ethanol were diluted so that each of the beverages contained a similar ethanol concentration (approximately 30 g/1). Food and fluid intake, growth rate and whole-body 65Zn were measured regularly over 11 d, after which animals were killed and blood haemoglobin (Hb) concentration, liver iron stores and the Zn concentration in testes determined.

2. There were no differences in body-weight gain or food intake between groups but fluid intake for the beer group was considerably higher than that for the other groups.

3. There was a significant effect of the type of alcoholic beverage consumed on whole-body 65Zn retention. Rats given whisky had a smaller daily loss of 65Zn than those given water, beer or cider. The ethanol group also showed a lower rate of 65Zn loss compared with the water group. The observed changes in whole-body 65Zn retention could be explained by an adverse influence of ethanol on Zn absorption from the diet.

4. Blood Hb and testes Zn concentration were similar in all groups but the type of liquid consumed influenced liver Fe levels. The cider group had the lowest liver Fe values and the ethanol group the highest values.

5. It is apparent from the present study that ethanol and alcoholic beverages affect Zn and Fe metabolism, but that the effects of ethanol are moderated by other components of the alcoholic beverages.

1. The amounts of magnesium, copper, zinc, phosphorus, manganese, potassium, vitamin B6, vitamin B12, folate, pantothenic acid, biotin, vitamin E and dietary fibre in the British household diet were calculated by applying appropriate values from recent analytical studies to the amounts of foods recorded in the National Food Survey during 1986.

2. National average intakes were (mg/person per d): Mg 247, Cu 1.25, Zn 9.0, P 1249, Mn 3.43, K 2694, vitamin B6 1.73, vitamin B12 6.33μg, folate 230μg, pantothenic acid 6.07, biotin 35μg, vitamin E 8.4. Regional and income-group differences were estimated, and found to be small. Additional contributions from alcoholic drinks and confectionery were also determined.

3. Dietary fibre was estimated both as unavailable carbohydrate and as non-starch polysaccharide. The national average intakes were 21.8 and 12.9 g/d respectively.

4. Intakes were compared with Canadian (Department of National Health and Welfare, 1983) and American (National Research Council, 1980) recommended dietary allowances (RDAs). With the exception of biotin, the Canadian RDAs were met by the household diet but the much higher American RDAs were only met for vitamin B12 and pantothenic acid.

1. Peripheral blood mononuclear cells from eight healthy volunteers were cultured, with or without concanavalin A (Con A), in a medium containing (ml/1) 100 normal autologous serum, 100 experimental autologous serum or 100 heterologous (fetal calf) serum.

2. The control and experimental autologous sera were obtained from the volunteers, before and after 15 d supplementation with 15 g fish oil (MaxEPA)/d to provide 1.5 g eicosapentaenoic acid (EPA; 20:5n-3)/d. The sera were frozen at -20°. The level of EPA increased from trace quantities in the control autologous serum to 14.3% w/w free fatty acids and between 6.9 and 8.1% w/w lipoprotein phospholipids in the experimental autologous serum. The heterologous fetal calf serum was enriched with EPA, complexed with bovine serum albumin, to provide a final concentration of 15μg/ml. All culture medium contained 10 ml fresh autologous serum/l and cells were obtained from the volunteers for the culture studies about 60 d after the end of EPA supplementation.

3. Portions of cells were removed from culture at 36, 48 and 72 h for phospholipid fatty acid analysis.

4. The level of EPA in phospholipids of cells cultured with exogenous EPA in fetal calf serum was increased significantly (P < 0.05) at all sampling times, both with and without Con A. By 48 h the levels had peaked at 15.8 (se 2.7) and 18.4 (se 4.5) % w/w respectively.

5. Resting cells, i.e. with no Con A present, failed to accumulate EPA when cultured in the experimental autologous serum containing 8.6% w/w total lipids as endogenous EPA. When cells were stimulated to divide by the mitogen Con A, there was a gradual increase in phospholipid EPA levels of mononuclear cells cultured with experimental autologous serum containing endogenous EPA. The maximum level obtained was at 72 h (7.2 (se 2.7)).

6. In a separate experiment, the effect of Con A at increasing doses (0, 1,5, 10 and 20 μg, final concentration) on lymphocyte blastogenesis was determined by estimating the incorporation of 3[H]thymidine. No significant effects due to serum in the culture medium were observed.

1. Giving diets containing 100 g fully-refined, non-hydrogenated fish oil/kg to rats caused substantial modification of skeletal-muscle-membrane fatty acid composition compared with control animals fed on an equivalent diet containing 100 g maize oil/kg.

2. Total muscle arachidonic acid (20:4ω6) was reduced from 138 (sd 25) mg/g total fatty acids to 15 (sd 2) mg/ g and phospholipid arachidonic acid content showed equivalent changes.

3. Reduction in muscle arachidonic acid content had no influence on the growth of individual muscles.

4. Variation in muscle fatty acid composition exacerbated the response of muscle to calcium-induced damage assessed by efflux of intracellular creatine kinase (EC 2.7.3.2).

5. It is concluded that metabolites of arachidonic acid are unlikely to be primary controlling factors of muscle growth or specific mediators of muscle sarcolemmal damage leading to enzyme efflux.

1. Gum arabic and wheat bran were added to an elemental diet (100 g/kg) in order to study their metabolism in the caeca of adult male albino Wistar rats.

2. Dry stool weight (g/d) over 12 weeks was 0.70 (SE 0.05) on the elemental control diet. Wheat bran increased mean dry stool weight to 1.09 (SE 0.08), an increase of 56 %. There was no significant difference between faecal weights (0.65 (SE 0.08)) of the gum-arabic-supplemented group and the unsupplemented group.

3. Wet caecal-sac weight, dry caecal-contents weight, and faecal and caecal bacterial mass (measured by 2,6-diaminopimelic acid) all increased significantly with the gum-arabic-supplemented diet but not with the wheatbran-supplemented diet.

4. Total short-chain fatty acids (mostly acetate) increased in the caecum and faeces with the gum-arabic-supplemented diet but not with the wheat-bran-supplemented diet.

5. Breath hydrogen and methane production decreased to negligible amounts over the 12 weeks of the experiment.

1. Changes in basal metabolic rates (BMR), following alterations in the preceding day's dietary protein (8.6, 11.5 and 14.0% of energy) were studied in eight, young, healthy adults over 4d.

2. Results showed a significant training effect, with BMR values 4.8 % lower on day 4 of the study period. Analysis of the results by ANOVA revealed a significant interaction between subjects and diets (P<0.005), a significant difference between subjects but no differences in BMR due to the protein content of the diets.

3. Mean coefficient of variation (CV) for intra- and inter-individual differences in BMR from day-to-day was of the order of 4 and 9% respectively.

4. Changes in protein content of the preceding day's diet do not influence variations in BMR which appear to be random in nature with a true CV of 3.8%.

1. Anthropometric indices are presented for 402 healthy Chinese elderly subjects leading an active life in the community in Hong Kong.

2. Women had higher body-mass index (weight/height2) and body fat, while fat-free mass, arm-muscle circumference and corrected arm-muscle area were higher in men. Body-mass index, fat-free mass, arm-muscle circumference and corrected arm-muscle area did not decline with age. Total body fat was lower in women aged 75 years and above compared with those aged 60–64 years.

3. All values were lower than those for elderly Caucasians. A different criteria for severe wasting malnutrition among elderly Chinese should be established.

1. Five healthy volunteers whose usual fat and energy intakes were moderately high (fat intake 155 (SE 11) g/d; energy intake 13683 (SE 909) kJ/d) were given on two separate occasions (a) 96 g fat and (b) 96 g fat and intravenous (IV) glucose (250 g glucose/1; 100 ml followed by a 2 ml/min infusion for 180 min).

2. Subjects continued on a low-fat diet for 35 d (fat intake 25 (SE 4) g/d; energy intake 6976 (SE 539) kJ/d) and the tests repeated.

3. The gastric inhibitory polypeptide (GIP) response to oral fat was significantly attenuated by IV glucose whilst subjects were consuming their normal diets and the GIP response to fat alone was significantly diminished during the low-fat diet. Post-prandial plasma triglycerides, light scattering indices (LSI; an index of post-prandial chylomicronaemia) and paracetamol levels paralleled the integrated GIP responses on both normal and low-fat diets.

4. The study of oral fat with or without glucose was repeated on seven further volunteers consuming their usual diet, substituting 10 MBq 99Tcm-labelled tin colloid for the paracetamol to investigate the rate of gastric emptying by radionuclide imaging.

5. Plasma GIP, insulin, triglyceride and LSI levels were similar to those found in the first study. IV glucose almost doubled the gastric emptying time of the oral fat load (half emptying time (t½) 148 (SE 11) min after fat alone and 224 (SE 18) min after fat and IV glucose). Post-prandial plasma motilin levels were significantly depressed by IV glucose.

6. We conclude that (a) the GIP response to oral fat is attenuated both by IV glucose and by a low-fat diet, (b) the delay in gastric emptying induced by IV glucose may be partly responsible for the diminished GIP response to oral fat when IV glucose is infused, (c) it is possible that some of the changes observed with IV glucose are mediated via changes in motilin.

1. The energy balance and activity allocation of eight male and eight female Indian farmers were meaured for 4 d during 10 months in both the dry and wet seasons of 1983.

2. All food prepared and eaten was weighed and nutrient values were calculated from food composition tables.

3. Average energy costs per unit mass for fifteen tasks were estimated from data obtained using a Kofranyi-Michaelis respirometer. Each subject was observed from 05.00 to 20.00 hours and activities were recorded for each minute. The remaining activity was determined by recall.

4. Activity allocation was categorized qualitatively into time spent on economically productive work, free time and body maintenance.

5. The mean weight for male subjects was 48.2 kg; the average female weight was only 36.9 kg. The mean height for male and female subjects was 1.61 m and 1.49 m respectively.6. For male subjects, the daily mean energy intake of 9.81 MJ (2350 kcal) was close to the calculated energy output of 9.54 MJ (2285 kcal).

7. The women's calculated daily expenditure of 8.22 MJ (1968 kcal) was slightly higher than their mean energy intake of 7.73 MJ (1852 kcal).

8. Although intake and output varied in relation to sex, weight and wealth the mean intake per kg body mass was equal for both males and females at 210 kJ (50 kcal) per kg. This is close to the minimum requirement for active Third World farmers.

9. The women spent significantly more time on economically productive work activities than the men (11.1 v. 8.1 h/d). Although female energy intake was 27 % less than males, their productive work time was 27% higher.

1. We have recently shown that the stellate cells, under normal conditions, contain a majority (more than 80 %) of the total store of retinol in liver (Blomhoff et al. 1985).

2. In the present work we have studied the role of the various liver cells in rats of different ages, sex and vitamin A status.

3. In most of these groups of rats, storage of retinol in parenchymal cells was proportional to the liver store of retinol, and less than 10% of total retinol in the liver could be recovered in the parenchymal cells. The only exception was parenchymal cells isolated from vitamin A-deficient rats. In rats containing 5 nmol retinol/g liver, about 16% of total retinol could be recovered in parenchymal cells, while in rats with only 1 nmol retinol/g liver, about 40% of total retinol could be recovered in parenchymal cells.

4. These results indicate that parenchymal cells played a minor role in liver storage of retinol, and that stellate cells stored more than 90% of liver retinol in most instances. Only in rats with a low retinol status did the percentage of retinol in parenchymal cells increase.

1. Possible links between metabolism and satiation were investigated using volunteer subjects given test meals based on milk solids. Satisfaction was rated by the subjects on a six-point scale and the course of metabolism was followed by measurement of the respiratory quotient (RQ).

2. The time-course of satiation was the same for a high-carbohydrate, a high-fat and a high-protein meal, in spite of the very different time-course of metabolism. The degree of satiation was reduced by added sodium chloride, without affecting the RQ rise. On the other hand, calcium chloride produced a suppression of the RQ rise without altering the satiation.

3. It is proposed that the results indicate that the primary receptors responsible for post-prandial satiation lie within the gut wall and that there is probably a number of receptor types. Likely candidates for these receptors are the gut hormone-secreting cells.

4. Although very-low-protein meals produce less satiation than meals containing 220 g protein/kg dry weight, there is no additional satiation obtained by increasing the protein level further. This is not inconsistent with the possibility of a protein hunger separate from an energy hunger.

1. The thermogenic, cardiovascular and metabolic responses to the ingestion of a 30 kJ/kg body-weight test meal were studied in six normal weight, female subjects before and after a 7 d period of underfeeding at 60 kJ/ kg ideal body-weight per d.

2. With underfeeding there were decreases in body-weight, plasma insulin and 3,5,3'-triiodothyronine concentrations, resting metabolic rate and respiratory exchange ratio, with increased blood ketone levels. Baseline ‘arterialized’ venous plasma noradrenaline and adrenaline concentrations were not affected by underfeeding.

3. Ingestion of the test meal caused similar increases in heart rate and calf blood flow and changes in blood pressure in the fed and underfed states. There was a greater glycaemic response to the test meal in the underfed state compared with the fed state although the rise in plasma insulin concentration was similar and ketogenesis was suppressed. The increases in metabolic rate and plasma noradrenaline concentrations following the test meal were similar in the fed and underfed states.

4. Although the period of underfeeding in the present study led to considerable metabolic adaptation, and some alteration in physiological responses to ingestion of a test meal, there was no evidence that there were associated changes in sympathetic nervous system activation.