1. The influence of a deficiency or surplus of thiamin in the diet on voluntary ethanol consumption, ethanol elimination rate and blood acetaldehyde concentration was studied in rats.

2. Both the high-thiamin diet containing 20 mg thiamin hydrochloride/kg and the thiamin deficient diet containing no measurable thiamin produced obvious functional effects on thiamin metabolism in rat tissues after 4 weeks as demonstrated by measurements of the blood transketolase (sedoheptulose-7-phosphate: D-glyceraldehyde-3-phosphate glycolaldehyde-transferase; EC 2.2.1.1) activity and the extent of thiamin pyrophosphate-stimulation of the enzyme.

3. During the first week on the test diets the prospective ethanol free-choice groups had 1.72 M-ethanol as their only drinking-fluid. Subsequently they had a choice between ethanol and tap water for three weeks. During the free-choice period the rats on the high-thiamin diet drank only one-fifth as much ethanol as the rats given the optimum diet with 4 mg thiamin hydrochloride/kg.

4. The thiamin-deficient rats showed a significant tendency to increase ethanol drinking, when intake was expressed relative to total energy intake, but their intake of ethanol on a g/kg body-weight basis was approximately the same as that of the group given the optimum-diet.

5. The observed differences in voluntary ethanol drinking associated with different levels of dietary thiamin cannot be explained by changes in the ethanol elimination rate or the acetaldehyde accumulation in blood during the oxidation of ethanol.

1. Changes in total retinol-binding protein (RBP), the holoprotein (holoRBP) and prealbumin (PA) concentrations have been monitored in plasma of thirty protein- and vitamin A-deficient preschool children from within a few hours up to 7 weeks after treatment with retinol and a good-quality protein diet.

2. The children were classified into groups according to nutritional status as having either kwashiorkor, marasmus-kwashiorkor or marasmus, and given formula diets whose protein and energy contents increased stepwise from 1 g and 105 kJ/kg body-weight respectively up to 4 g and 733 kJ/kg body-weight after 4 weeks. Retinol was administered in the forms of retinyl palmitate either orally or intramuscularly.

3. PA and total RBP were determined by electroimmunoassay procedures and the holoRBP by its fluorescence after separation from other plasma proteins.

4. RBP in plasma of the vitamin A-deficient child is largely denatured and incapable of binding administered retinol, which must first be taken up by the liver before native holoRBP is released. An increased pool of native apoprotein accumulates in the liver during vitamin A deficiency which is released into plasma quickly after retinol uptake to form peak concentrations of total and holoRBP approximately 3 h after dosing intramuscularly and 6 h orally.

5. The accumulated pool of RBP was highest in livers from the marasmus group and lowest in those from the kwashiorkor group, reflecting their relative capacities to synthesize plasma proteins.

6. The mean plasma concentrations of total and holoRBP for the various groups were minimal 24–48 h after dosing with retinol and then improved almost linearly over the following week.

7. Mean plasma PA concentrations of the various groups on admission were also in order of the severity of their malnutrition. There was little or no change in this protein concentration over the first 24 h after dosing with retinol, but thereafter the mean values rose almost linearly over 2 weeks. Albumin on the other hand changed little during the first week. The results show that PA is the more sensitive measurement of protein nutritional status.

1. Male Black and White Hooded rats were allocated at birth to foster mothers in litters of three, nine or sixteen. At weaning animals from each of these litter sizes were ad lib.-fed on a stock diet forming three ad lib.-fed control groups. At weaning further animals from litters of nine and sixteen were fed on the stock diet in restricted amounts until 12 weeks of age. These undernourished animals were then rehabilitated by being allowed ad lib. access to the stock diet.

2. Five animals from each group were killed at various stages of the experiment, their bodies analysed for fat and nitrogen, and the size and number of cells determined in four specific fat depots.

3. The previously undernourished rats failed to make a complete recovery and were significantly smaller than ad lib.-fed animals from the same litter size at 32 weeks of age when the experiment was terminated.

4. The previously undernourished rats from litters of nine deposited a significantly greater proportion of fat in their bodies during rehabilitation than ad lib.-fed animals from litters of nine over the same gain in body-weight. The previously undernourished rats from litters of sixteen deposited the same proportion of fat in their bodies during rehabilitation as ad lib.-fed animals from litters of three, nine and sixteen over the same gain in body-weight.

5. There were no significant differences in apparent or total fat cell numbers between ad lib.-fed animals and undernourished-rehabilitated animals at any of the four sites studied at 32 weeks of age.

1. Eighteen males (31–62 years) who habitually consumed significant amounts of table sucrose (approximately 25% of total carbohydrate intake) were supplied with their usual intake of sucrose for consumption in conjunction with their normal diet for 1 year, and a record kept of the amount consumed. The sucrose was then replaced isoenergetically by dried glucose syrup (55 D. E.) which contained saccharin to equate the sweetness to that of sucrose.

2. Fasting blood samples were taken every 4 weeks during the 2 years, and the plasma analysed for glucose, cholesterol, triglycerides and phospholipid-P by automated colorimetric methods. Dietary questionnaries were issued every 3 months to confirm that subjects were not substantially altering their diets.

3. In subjects whose weight remained unchanged and in those who lost weight there was a significant fall in cholesterol (P < 0.025) and phospholipid (P < 0.025) in the glucose-syrup period compared with the sucrose period; triglycerides did not change. In subjects who gained weight there was a significant increase in triglycerides (P < 0.05), but no change in cholesterol; phospholipid-P fell significantly (P < 0.0005).

4. The dietary modification in this experiment was sufficiently long to ensure that subjects had adapted, and the results obtained show stable changes in blood lipids which may be attributed to the isoenergetic replacement of table sucrose by glucose syrup.

1. Rats which have been maintained for ten to twelve generations on diets of low protein value were rehabilitated in utero (group P), from birth (group F) and from 4 weeks of age (group W).

2. Group W showed little change in physique, behaviour or learning, indicating that for recovery to be effective refeeding must begin earlier.

3. Group F just failed to attain full physical recovery (90%) whereas group P overgrew by 18.6% in weight and 8.5%; in length.

4. In a test designed to evaluate learning ability rehabilitated rats of groups P and F were significantly less successful than normal rats, but more successful than rats of group W or rats of the original undernourished colony.

5. Rehabilitation for a further two generations in groups F and P corrected any residual physical and behavioural defects but produced no further improvement on the Lashley (I 938) jumping platform.

1. Male Wistar rats were allocated at birth to foster mothers in litters of three, nine or sixteen. At weaning animals from each litter size were ad lib.-fed on a stock diet. Further animals from litters of nine and sixteen were fed on the stock diet in restricted amounts until 12 weeks of age and then rehabilitated by being allowed ad lib. access to the stock diet.

2. Five animals from each group were killed at 24 weeks of age and the size and number of cells determined in four specific fat depots.

3. Animals reared in litters of sixteen and further undernourished from 3 to 12 weeks (group L16/U) had significantly fewer fat cells at all sites studied than animals reared in litters of three and ad lib.-fed. Group L16/U animals also had significantly fewer observable fat cells at the epididymal site than ad lib.-fed animals reared in litters of nine. These results differ from those found in the Black and White Hooded rat where, after similar treatments, no significant differences in observable fat cell number were found.

1. The metabolic effects of increasing or decreasing the usual energy intake for only 1 d were assessed in eight adult volunteers. Each subject lived for 28 h in a whole-body calorimeter at 26° on three separate occasions of high, medium or low energy intake. Intakes (mean±SEM) of 13830 ± 475 (high), 8400 ± 510 (medium) and 3700 ± 359 (low) kJ/24 h were eaten in three meals of identical nutrient composition.

2. Energy expenditure was measured continuously by two methods: direct calorimetry, as total heat loss partitioned into its evaporative and sensible components; and indirect calorimetry, as heat production calculated from oxygen consumption and carbon dioxide production. For the twenty-four sessions there was a mean difference of only 1.2 ± 0.14 (SEM)% between the two estimates of 24 h energy expenditure, with heat loss being less than heat production. Since experimental error was involved in both estimates it would be wrong to ascribe greater accuracy to either one of the measures of energy expenditure.

3. Despite the wide variation in the metabolic responses of the subjects to over-eating and under-eating, in comparison with the medium intake the 24 h heat production increased significantly by 10% on the high intake and decreased by 6% on the low intake. Mean (± SEM) values for 24 h heat production were 8770 ± 288, 7896 ± 297 and 7495 ± 253 kJ on the high, medium and low intakes respectively. The effects of over-eating were greatest at night and the resting metabolic rate remained elevated by 12% 14 h after the last meal. By contrast, during under-eating the metabolic rate at night decreased by only 1%.

4. Evaporative heat loss accounted for an average of 25% of the total heat loss at each level of intake. Changes in evaporative heat loss were +14% on the high intake and −10% on the low intake. Sensible heat loss altered by +9% and −5% on the high and low intakes respectively.

5. It is concluded that (a) the effects on 24 h energy expenditure of over-feeding for only 1 d do not differ markedly from those estimated by some other workers after several weeks of increasing the energy intake; (b) the resting metabolic rate, measured at least 14 h after the last meal, can be affected by the previous day's energy intake; (c) the zone of ambient temperature within which metabolism is minimal is probably altered by the level of energy intake.

1. The proportion of iron liberated from twenty foods was measured after incubation in vitro with human gastric juice.

2. Results with samples of gastric juice obtained from one subject on ten occasions and from sixteen subjects on a single occasion showed good agreement, the proportions of Fe liberated covering the entire range from zero for egg to 1.0 for wine.

3. Where there were small variations between the results obtained with different samples of gastric juice attempts were made to correlate these with peptic activity, various proteins and mucoproteins, pH and total and free acid; the only factors that varied with the proportions of Fe solubilized were the various measures of acidity.

4. The results correlated highly with those of Layrisse et al. (1969) for the in vivo absorption of Fe from similar foods, although the samples used were not the same.

5. The amounts of Fe solubilized when the foods were mixed with bran, oats or egg (known to reduce the in vivo absorption of Fe from foods) were less than calculated from the sum of each, with two exceptions.

6. The results obtained with human gastric juice differed from those obtained with in vitro methods prcviously reported, namely treatment with dilute hydrochloric acid and double incubation with pepsin plus HCI at pH 2.5 followed by adjustment to pH 7.5.

7. The amount of Fe solubilized from soya-bean flour by gastric juice was compared with that solubilized by pepsin plus HCI; both systems were shown to be pH dependent but the amount of Fe liberated with pepsin- HCI was much greater than that known to be absorbed by man in vivo.

8. It is suggested that incubation with human gastric juice may permit in vitro analyses of ‘chemically- available’ Fe in foods and thus be of value in food composition tables in terms of ‘Fe equivalents’ even though the amounts absorbed in vivo are subsequently influenced by other ingredients of the diet and by the Fe status of the individual.

1. The effect of supplementing barley diets with urea (U), extracted, decorticated groundnut meal (GNM) or Peruvian fish meal (PFM) on rumen bacterial protein synthesis and the proportion of undegraded food protein passing to the duodenum of sheep has been examined.

2. Three wethers were given isonitrogenous, isoenergetic diets containing (g/kg dry matter (DM)): U 20, GNM 106 or PFM 78, the crude protein (nitrogen × 6.25) contents being 139, 145 and 148 respectively. The sheep were fed hourly, the mean daily intake of DM being 0.634 kg.

3. Rumen bacterial protein synthesis was determined using 35S and diaminopimelic acid (DAPA) as bacterial markers and polyethylene glycol (PEG) and chromic oxide as markers of digesta flow. Rumen volatile fatty acid (VFA) production rate was determined by a continuous infusion of [I-14C]acetate. 4. and DAPA gave similar estimates of the proportion of bacterial N in the trichloroacetic acid- precipitable nitrogen of the rumen digesta, the mean value being 0.86. The VFA production rate did not vary significantly between diets, the mean being 5.8 mol/24 h. The flow of bacterial N from the rumen was calculated from the PEG and Cr2O3, estimates of flow and the 35S and DAPA estimates of the proportion of bacterial N in the rumen. and DAPA gave similar values (mean 12.5 g/24 h) and Cr2O3, gave a slightly lower value (11.5 g/24 h) than PEG (13.5 g/24 h). Dietary effects, averaged over the four methods, were not significant; the values were 13.0, 13.4 and I 1–0 g/24 h for the U, GNM and PFM diets respectively.

5. Duodenal samples were taken from two 12h continuous collections from re-entrant cannulas and the DM flow adjusted to total recovery of Cr2O3,. The mean recovery of Cr203 at the duodenum was 0.798. The rates of flow of DM were 0.296,0.311 and 0.334 kg/24 h and of non-ammonia-N (NAN) 13.5, 15.2 and 15.4 g/24 h on the U, GNM and PFM diets respectively.

6. The concentrationsof the essential amino acids in duodenal digestaweregenerally higher with the PFM diet than with either of the other two diets. The flow of most amino acids through the duodenum was generally higher on the PFM and GNM diets than on the U diet.

7. The energetic efficiency of bacterial protein synthesis was calculated to be 2.1 g bacterial N/mol VFA or 28 g bacterial N/kg organic matter fermented in the rumen.

8. From the estimates of bacterial N flow from the rumen and NAN flow through the duodenum it was calculated that 0.22 and 0.69 of the supplemental N from GNM and PFM respectively passed through the rumen undegraded.

1. Well-nourished rats were injected with tritiated thymidine at 15, 22, 28 or 84 d of age. At 1, 6, 11 and 16 d after injection animals from each group were killed, samples of adipose tissue were removed from two subcutanecus sites (abdominal and scapular) and separated, using collagenase (EC 3.4.24.3), into ‘fat cell’ and ‘stromal cell’ fractions. The specific (radio)activity of DNA isolated from each fraction was measured. The specific activity of DNA isolated from two ‘deep body’ sites (perirenal and epididymal) was measured only in the animals injected at 84 d of age.

2. Animals undernourished from birth up to 84 d of age were injected with tritiated thymidine at 22, 28 or 84 d of age. Animals were killed 1 and 11 d after injection, adipose tissue removed, and the specific activity of DNA measured. Other undernourished animals were rehabilitated from 84 to 107 d and injected at 91 d of age with tritiated thymidine. The animals were killed 1, 6, 11 and 16 d after injection, adipose tissue was removed from the subcutaneous and deep body sites and the specific activity of DNA determined as before.

3. In well-nourished animals fat cell replication had largely ceased by 12 weeks of age in the subcutaneous depots. There were differences between the various sites of adipose tissue regarding the period of hyperplastic growth, its timing or rate of replication or both.

4. In undernourished animals replication was slow in the subcutaneous depots compared with well-nourished animals of the same age. Rehabilitation from undernutrition stimulated replication which resulted in higher rates in all four depots examined compared with those in well-nourished animals.

5. The findings are discussed in relation to the concept of a finite period of hyperplasia for adipose tissue.

1. Iron absorption from maize (Zea mays) and sorghum (Sorghum vulgore) beer was more than twelvefold greater than from a gruel made from the constituents used to prepare the beer.

2. The effect of changes occurring during brewing were investigated. These changes include a decrease in the solid content, and the formation of 30 ml ethanol/l and 5 ml lactic acid/].

3. The presence of solid material was found to inhibit Fe absorption markedly, especially when the solid content was 100 g/l or more.

4. The presence of ethanol potentiated Fe absorption but the effect was only modest in gruels with a high solid content.

5 Fe absorption from a 2 ml lactic acid/] solution was four-fold greater than from a hydrochloric acid solution of the same pH. When lactic acid was added to a gruel containing 200 8 solids/l the mean absorbtion rose from 0.4 to 1.2%.

6. In a direct comparison, Fe absorption from beer was significantly better than from a gruel of similar pH containing lactic acid.

7. The results suggest that at least three factors are responsible for the enhanced Fe absorption from maize and sorghum beer. These include the removal of solids during fermentation and the presence of ethanol and of lactic acid in the final brew.

8. In order to reproduce the way in which beer is brewed domestically in Fe containers, a study was done in which beer was prepared in the presence of Fe wire. Under such circumstances Fe was rapidly dissolved and the final Fe concentration of the brew was 89 mg/l. However, the nature of the Fecontaining compound or compounds was not elucidated.

1. Total carbohydrate (CHO) and ingested glucose oxidation was measured in five obese subjects with normal glucose tolerance after an oral load of 100g naturally-labelled [13C]glucose using indirect calorimetry and mass spectrometry respectively.

2. CHO utilization rate (107 ± 14 mg/min in the post-absorptive state) increased 30 min after the glucose load to reach a plateau (245±25 mg/min) between 90 and 120 min. It then decreased to basal values at 330 min. Cumulative CHO oxidation over 480 min was 66±7 g and the CHO oxidized above basal levels was 26 ± 7g.

3. Enrichment of expired carbon dioxide with 13c began at 45 min and maximum values were observed between 210 and 300 min. At 480 min, cumulative oxidation of the ingested glucose was 24± 2 g.

4. Compared with controls, the obese subjects exhibit an impairment of CHO utilization which precedes glucose intolerance. This impairment can be explained by an increased availability of free fatty acids which favours lipid oxidation at the expense of ingested [13C]glucose oxidation.

1. Transfer potentials were obtained from everted jejunal sacs prepared from fed euthyroid, fasted euthyroid, fed hypothyroid and fasted hypothyroid rats by addition of serial concentrations of the dietary sugars glucose and galactose and the glucalogues 3-O-methyl glucose, α-methyl glucoside and 6-deoxy-D-glucose to the incubation fluids. The kinetic parameters of ‘apparent Michaelis constant’ (apparent Km) and maximum transfer potential difference (pdmax) obtained from the results were used to characterize the changes in the electrogenic transfer mechanisms for these substrates.

2. Analysis of the significant differential changes in values for ‘apparent Km’ and pdmax for the two dietary sugars and the three glucalogues indicated heterogeneity in the mechanisms for sugar transfer across the intestine and suggested a minimum of four possible carriers.

3. The validity of using glucalogues to characterize changes in the transfer mechanisms for the dietary sugars in different dietary and hormonal states was assessed. None of the kinetic parameters for electrogenic glucalogue transfer matched those for the dietary sugars in all the experimental conditions. The employment of glucalogues to assess changes in electrogenic transfer mechanisms for dietary sugars can thus lead to invalid conclusions.

4. Fasting decreased the ‘apparent Km’ of the dietary sugars and the glucalogues. However, the pdmax values for glucose, galactose, and α-methyl glucoside decreased whereas those for 3-O-methyl glucose and 6-deoxy-D-glucose did not.

5. Hypothyroidism showed different effects in fed and fasted intestine. Because hypothyroidism induced a reduction in food intake, separation of the direct effects of the condition on electrogenic transfer from reduced food intake effects was not possible.

1. Iron-deficiency anaemia continues to be a major public health problem in all developing countries. Fortification of commonly consumed food items has been suggested as an effective method of preventing anaemia. Common salt (sodium chloride) has been identified as a suitable vehicle to be fortified with Fe in India.

2. Common salt was fortified with ferric orthophosphate (3500 mg/kg) and sodium hydrogen sulphate (5000 mg/kg) to provide an additional 1 mg elemental Fe/g common salt consumed.

3. After ascertaining the acceptability of the fortified salt with respect to its colour, taste and bioavailability a pilot feeding trial was conducted among residential schoolchildren in Hyderabad. Feeding of the fortified salt for a period of 1 year resulted in a significant increase in the haemoglobin level of these children. There was also a significant reduction in the prevalence of anaemia among children given the fortified salt.

4. Before the same fortified salt is recommended as a public health measure to prevent Fe-deficiency anaemia among our population it is necessary that further large-scale community trials with this fortified salt are carried out particularly among the rural population.

1. The effect of energy and protein intake on the growth, food efficiency and nitrogen retention of artificially-reared pigs was studied over three 8 d periods between 8–32 d of age in an experiment employing a 5×3×2 factorial design. The factors were initial energy: N value (I; 250, 355, 460, 565 or 670 kJ/g N), rate of increase of 1 at 8 d intervals (0, 12.5 or 25%) and plane of nutrition (three times daily to appetite or 75% of this intake).

2. The range of energy: N values was obtained by formulating five diets based on dried skim milk, lactose and casein and feeding appropriate combinations of two diets. The diets, which were pelleted, contained 100 g maize oil/kg and the gross energy content was approximately 20 MJ/kg.

3. N digestibility was high at all three age intervals, reaching 0.99 on the diet containing the highest dietary crude protein (N × 6.25) level. Metabolic faecal N excretion was found to be 1.1 g/kg dry matter (DM) intake.

4. Growth rate, feed conversion ratio (kg food intake/kg wt gain; FCR), N retention (NR) and the proportion of digested N retained (NR:apparent digested N (ADN)) were significantly (P < 0.001) affected by I values at all age intervals and the responses were quadratic. Response curves were calculated by the least squares method and optimum values of I determined for each of the criteria.

A constant energy:N value of approximately 400 kJ/g N was indicated by growth, FCR and NR optima but the NR:ADN value fell from 0.77 for the 8–16 d period to 0.60 for the 24–32 d period at this I value. It is concluded that a suitable compromise would be an I value of 470 kJ/g N increasing by 10%/week.

5. There was a significant interaction between plane of nutrition and I values on FCR between 16–24 d (P < 0.001) and 8–32 d (P < 0.01) indicating that FCR was better at high protein levels and worse at low protein levels when the diets were fed on the lower plane of nutrition.

1. The total food and drink available for human consumption in the United Kingdom would provide approximately 13 MJ (3100 kcal)/person per d, while the energy intake recommended for the population is approximately 9.6 MJ (2300 kcal)/person per d. A proportion of this substantial difference must be due to wastage in the home as well as in catering establishments and during the storage, distribution and processing of food.

2. As part of a general investigation of this problem, a representative sample of 1000 British households was asked to collect all the potentially-edible food wasted in their homes during 1 week, and to keep a record of the food, other than commercial pet food, which they gave to pets and wild birds. A total of 672 households co-operated fully, 338 in summer and 334 in winter. Each food sample received was weighed, and its energy content was determined calorimetrically.

3. Significantly more waste food was collected in summer than in winter, equivalent to 9.3 MJ (2220 kcal)/household per week and 7.1 MJ (1700 kcal)/household per week respectively. In terms of energy, cereals, fat and meat wastage predominated, while in terms of weight, milk was more important and fat less so.

4. Considerable quantities of otherwise edible food were also given to pets and birds, accounting on average for a further 2.4 MJ (570 kcal) and 3.0 MJ (710 kcal)/household per week in summer and winter respectively. The energy content of all food wasted in the home therefore averaged 11.7 MJ (2790 kcal)/household per week in summer and 10.1 MJ (2410 kcal)/household per week in winter, equivalent to 0.6 MJ (150 kcal) and 0.5 MJ (130 kcal)/person per d respectively. This is less than one-quarter of the gap between food supplies and the amount of food thought to be eaten in the UK.

5. Food wastage was significantly influenced by the composition of the family, with adults wasting more in absolute terms than children, and larger households wasting less per person than smaller households. However, with few exceptions, neither income nor geographical region significantly affected the total amount of food wasted in the home.

6. When assessed against the expected usage of food in the home, wastage accounted on average for 6.5% of the energy intake in summer and 5.4% in winter.