1. Male guinea-pigs were assigned to four different groups at birth. The heaviest group of animals was severely undernourished from 21 d of age (weight gain: 1.2 g/d v. 10 g/d for normally-fed animals).

2. At 35, 45, 55 and 65 d of age in normally-fed animals, and at 45 and 55 d of age in undernourished animals, blood testosterone levels were determined by radioimmunoassay, epididymidal tissue examined for the presence of spermatozoa and testes sectioned for rating of spermatogenesis using light microscopy.

3. Sexual maturity in terms of potential fertility (spermatozoa in the epididymis) was reached by all normally-fed animals between 45 and 55 d of age. High birth-weight animals had a higher incidence of the most advanced stages of spermatogenesis than low birth-weight ones at the various ages studied. In the undernourished animals spermatogenesis was clearly delayed.

4. Plasma testosterone concentrations were already in the adult range at 35 d and independent of age and birth-weight. The undernourished animals, however, had very low levels. Maintenance of spermatogenesis seemed compatible with low plasma levels of testosterone.

5. It is concluded that the timing of testicular development seems to be determined by the time the animals are born and appears to be unaffected by severe undernutrition from 21 d of age.

1. During the course of a nutritional survey on an Antarctic base, leucocyte ascorbic acid estimations (Denson & Bowers, 1961) were found to be significantly affected (P < 0.0001) by the leucocyte count measured during analysis.

2. The effect was significantly less (P < 0.05) when leucocyte levels were at or near saturation than when subsaturated.

3. This suggests that leucocytes share available ascorbic acid, especially in subsaturated subjects, and that assessment of nutritional status from the leucocyte ascorbic acid level should take account of the leucocyte count and the plasma ascorbic acid titre.

1. The effect of fortification of food with iron to provide 10 mg elemental Fe/child per d was studied in preschool children maintained on a cereal diet, over a 5-month period.

2. The absorption of 5 mg Fe as ferrous sulphate mixed in one meal was 3.3% of the test dose and when 3.3 mg was given with each of three meals over a 2 d period the corresponding value was 4.8%.

3. The mean absorption of a test dose of ferrous ascorbate studied in twenty-four children midway through the trial was 42%.

4. The only beneficial effect of Fe fortification in this time-period in the experimental group was the prevention of the decrease in packed cell volume which occurred in the control group.

1. Rats were given low-fat diets for 3 d in which the carbohydrate source was starch. The livers of animals given the fructose or sucrose had increased hepatic activities of the fatty acid synthetase and stearoyl CoA desaturase (EC 1.14.99.5) enzyme complexes: in those given fructose there was a lower activity of the enzymes in adipose tissue.

2. Similar results were obtained in rats given fructose diets for 30 d, but in animals which had previously been made diabetic with streptozotocin, the activities were lower. The dietary treatment made little difference to the fatty acid profiles of the tissue lipids. The diabetic condition on the other hand produced considerable changes in fatty acid profile.

3. With diets containing approximately 200 g fat/kg in the form of butter or of polyunsaturated margarine, the tissue lipids from rats given sucrose had less linoleic acid than those from rats given starch. In addition, there was the expected difference between the rats given butter or margarine. The results are discussed in relation to the current literature.

1. Carbohydrate (CHO) oxidation was measured simultaneously in a group of five normal subjects after an oral load of 100 g naturally-labelled [13C]glucose, using indirect calorimetry and mass spectrometry.

2. CHO utilization, calculated from the results of indirect calorimetry, increased 30 min after the glucose load to reach a peak at 90 min. It then decreased to reach basal values at 380 min. Cumulative total CHO oxidation at 480 min was 83±8g, and CHO oxidized above basal levels, 37±3 g.

3. Enrichment of expired carbon dioxide with 13C began at 60 min and maximum values were observed at 270 min. At 480 min, cumulative CHO oxidation measured by use of [13C]glucose was 29 g. The difference from calorimetric values can be attributed in part to the slow isotopic dilution in the glucose and bicarbonate pools.

4. Thus, approximately 30% of the glucose load was oxidized during the 8 h after its ingestion and this accounts for a significant part of the increased CHO oxidation (37 g), as measured by indirect calorimetry.

1. The amount of manganese in nationally-representative samples of prepared and cooked goups of foods, and in a wide variety of individual foods, was determined by atomic absorption spectroscopy.

2. The average British diet was calculated to provide 4.6 mg Mn/d of which half was derived from tea and other beverages, 30% from cereals, and 15% from vegetables and fruit. Animal products provided little Mn.

3. Individual foods other than tea which were particularly rich in Mn in Britain were unrefined and partially-refined cereals, and some spices and herbs. Some vegetables and fruit, coffee, wine, chocolate and brown sugar also contained significant amounts of Mn.

1. Fifteen pieces of rectus abdominus muscle and fifteen pieces of taenia muscle were removed from patients undergoing various surgical procedures.

2. The muscles were extracted, hydrolysed and the content of Nτ-methylhistidine was measured.

3. The rectus muscles contained 3.13±0.7 μmols Nτ-methylhistidine/g fat-free dry solid andthe taenia muscles 2.4±0.6 μmols/g fat-free dry solid. There was a statistically significant difference (P < 0.05) between these values using the Student's unpaired t test, although this could have been due to contamination of the taenia muscles with connective tissue.

4. The muscle content of Nτ-methylhistidine was at least 40% higher than the only other reported value and therefore the method of calculating muscle protein breakdown based on Nτ-methylhistidine excretion requires revision.

1. A study amongst schoolboys in villages around Hyderabad, India, showed that almost all the boys had riboflavin deficiency, 61% had pyridoxine deficiency, and 9.4% had thiamin deficiency as judged by enzymic tests.

2. The prevalence of angular stomatitis was 41.3% and that of glossitis was 18.2%. Biochemical deficiency of riboflavin and pyridoxine was marginally higher in children with angular stomatitis with or without associated glossitis, than in children without oral lesions.

3. Treatment with B-complex vitamins (containing 4 mg riboflavin and 10 mg pyridoxine) daily for 1 month produced significant reduction in the prevalence of glossitis but had no effect on angular stomatitis. The latter responded to topical application of gentian violet.

4. Small but significant changes in erythrocyte enzymes occurred over the period of 1 month even without vitamin supplements.

5. Results suggest that while glossitis is a relatively early manifestation of riboflavin or pyridoxine deficiency or both, angular stomatitis has a more complex aetiology perhaps associated with infection.

1. Rat sucklings (18-d-old) bred from vitamin B12-deprived dams were compared with vitamin B12-suplemented dams’offspring, which were considered normal rat sucklings.

2. The vitamin B12-deficient rat sucklings had lower body-weight, liver weight and brain weight.

3. Vitamin B12 deficiency was also evident from the tenfold lower concentrations of vitamin B12 in liver and cerebellum.

4. The concentration of liver lipid was markedly increased in vitamin B12-deficient rats; triacylglycerol accounted for most of the increase. In brain the lipid concentration was slightly decreased (P < 0.05).

5. The methylation of ethanolamine phosphoglyceride to choline phosphoglyceride was reduced in both liver and brain in vitamin B12-deficient rats, as measured after the administration of [14C]ethanolamine. A slight decrease in choline phosphoglyceride concentration could be a consequence of this finding. The composition of phospholipids was otherwise normal.

6. Odd-chain fatty acids (pentadecanoate and heptadecanoate) accumulated in both liver and brain of the vitamin B12-deficient rat sucklings and constituted approximately 1% of total fatty acid.

7. The biosynthesis of fatty acid and cholesterol from intraperitoneally-injected 3H2O and [14C]propionate was unchanged in vitamin B12 deficiency.

1. The effect of varying energy and protein intake on nitrogen balance in adult men engaged in heavy manual labour was investigated.

2. Low protein and energy levels resulted in negative N balance and urea index (Waterlow, 1963) was decreased.

3. Urinary excretion of hydroxyproline was found to be sensitive to dietary protein level, but not to energy.

1. The growth of muscle fibres was analysed by light microscopy in biopsies from subjects when malnourished, during nutritional rehabilitation, and after clinical recovery.

2. Muscle fibres from malnourished subjects were extremely atrophic (cross-sectional area, 110μm2). The fibres doubled in size during the early period of rehabilitation. Growth of muscle fibres during later periods of rehabilitation occurred at a slower rate.

3. The absolute rates of change in fibre sizes differed considerably between subjects, but the rates of change relative to the rate of gain of total body-weight (expressed as % recovery or % expected weight-for height (Nelson, 1975)) were similar between subjects after the initial growth spurt. The pattern of recovery appeared to differ between older and younger subjects.

4. Fibre sizes correlated with body-weight but not with age in the malnourished subjects. A significant correlation between fibre areas and either weight or age was observed during rehabilitation and after clinical recovery.

5. Fibre sizes of clinically-recovered subjects (mean age, 13.8 months; weight, 8.7 kg) were only approximately 60% of that for a well-nourished 6-month-old control subject (6.4 kg). These results suggest that a longer period of time is required for fibres to reach their expected size. Therefore, when the child has regained body-weight to that of a normal child of the same height, his muscles have not yet recovered and his body composition is abnormal.

1. A study was carried out on 973 school children to find out any relationship between vitamin B-complex deficiency signs and defective vision, and the effect of supplementation of B-complex vitamins on visual acuity.

2. The results of the study showed a significant association between presence of clinical signs of vitamin B-complex deficiency and defective vision.

3. Supplementation with vitamin B-complex was found to have beneficial effect in improving the visual-acuity status of defective children and in preventing visual defects from developing.

4. It is concluded, therefore, that from the present study it appears that the relationship between vitamin B-complex deficiency and visual defects could be one of ‘cause and effect’.

1. Effects of dietary composition, energy restriction, and diabetes on hexose absorption were examined by feeding male rats isoenergetic, semi-synthetic diets of differing carbohydrate and protein content. Diets were carbohydrate, (g/kg): 890 sucrose; carbohydrate-protein, 500 sucrose, 390 casein; or protein, 890 casein. An additional group was fed on commercial rat chow ad lib.

2. Hexose (3-O-methyl-D-glucose) absorption was measured by luminal perfusion of the entire small intestine in situ. Absorption by the total small intestine, i.e. absorption per rat, and absorption per g dry weight of mucosa (specific absorption) were calculated.

3. When semi-synthetic diets were fed at 210 kJ/d to normal animals absorption depended on composition of diets: carbohydrate enhanced or protein suppressed hexose absorption. Dietary carbohydrate as glucose, dextrimaltose or starch gave the same hexose absorption response as sucrose.

4. When diets of normal rats were restricted to 118 kJ/d, specific absorption was independent of dietary composition and was incresed for all dietary groups to the level of the group fed on the carbohydrate diet at 210 kJ/d.

5. When diabetic rats were given 210 kJ/d, hexose specific absorption was the same for all diabetic groups independent of dietary composition and was equal to that of controls given carbohydrate, but greater than that of protein-fed controls.

6. Thus, when two of the three stimuli (i.e. carbohydrate diet plus energy restriction or diabetes) were combined, the effect was not additive, and the response of hexose specific absorption to diabetes and energy restriction was the same: absorption was independent of dietary composition and was stimulated relative to controls fed on diets containing protein.

7. The pattern of response of total small intestinal hexose absorption to the stimuli of dietary composition, energy restriction and diabetes was similar to that of specific absorption.

8. Compared with groups given semi-synthetic diets, rats eating commercial rat chow ad lib. (approximately 286 kJ/d) showed increased mucosal mass and decreased specific absorption, but total absorption was similar to that of the carbohydrate and carbohydrate-protein-fed groups.

9. In a separate study in control rats, specific and total intestinal absorption of L-leucine did not respond to dietary composition, i.e. level of protein fed.

1. Weanling rats were fed on purified-casein diets containing active and inactive (autoclaved) field bean (Vicia faba L.) proteinase inhibitors (PI) at levels of 1.25, 2.5, 5.0 and 10 g/kg. Diets containing raw-and autoclaved-field-bean meal (FBM) were also given. The body-weight gain, protein efficiency ratio (PER); i.e. the ratio of the live weight gain in g/g of protein consumed and apparent nitrogen digestibility were determined 7, 14 and 21 d after the start of the trial.

2. Significant growth depression (P < 0.001) was observed in rats given diets containing 2.5 g/kg PI (27–35%). In rats fed on raw FBM growth depression was severe after 7 d (57%).

3. Food intake was depressed at PI inclusion levels of 5 g/kg and higher between 14 and 21 d.

4. PER was depressed significantly (33–44%) in rats given diets containing the active PI at all levels after 7 d. The protein utilization of all casein diets was higher than that of the FBM diets.

5. Apparent N digestibility was depressed in rats fed on diets containing 10 g/kg PI by 9 and 7% at 14 and 21 d respectively. The N digestibility of both raw and heated FBM was similar at approximately 84%.

6. It was concluded that the PI are not the main factors responsible for the growth depression observed when raw FBM is fed to rats.

1. The present study was considered as a first step to develop a method to measure food iron absorption from realistic common meals prepared and consumed by the subjects themselves in their own homes. The absorption of Fe from the meals was measured by means of the extrinsic-tag method modified to allow for a free choice of food items.

2. The mean Fe intake was 2.79 mg and the mean Fe absorption approximately 0.30 mg. The Fe status of the subjects corresponded to 31.5% absorption from a reference dose solution containing 3 mg elemental Fe as ferrous ascorbate. The variation in food Fe absorption obtained in this field study was found to be of the same magnitude as that obtained in studies performed under more controlled conditions as in the laboratory.

3. The conclusion was drawn that the proposed method could be used in realistic field studies aimed at, for example, explaining or preventing a high prevalence of deficiency. A sufficiently long run-in period and a careful instruction of the subjects was considered essential for the design of future field studies.