1. Individual energy intakes and expenditures of seven Tristan men aged between 16 and 57 years, and ten Tristan women aged between 15 and 61 years, were measured daily for 7 consecutive days between May and October 1966.

2. Details of the subjects' main activities together with the energy cost of these activities are given.

3. The mean daily calorie intakes were 2650 kcal for men and 1830 kcal for women; the mean expenditures were 2860 and 2060 kcal per day respectively. Separate values are given for two individuals, a brother and sister, who gave results bearing no resemblance to those of the rest of the subjects.

4. Protein, fat, carbohydrate and alcohol accounted for 12.7, 29.6, 53.7 and 40 % respectively of the men's total calorie intake and 11.9, 27.2, 61.0% and 0% of the women's total calorie intake. The fat content of the diet was low when compared with that of the Islanders' diet while in England, though total calorie intake was greater (Taylor, Hollingsworth & Chambers, 1966). More than half the total calorie intake was provided by processed foodstuffs, but island produce provided a large proportion of the protein in the diet.

5. It is deduced that mean energy requirements of about 2750 kcal per day for men and 1950 kcal per day for women are adequate for the Tristan population and that there are sufficient food supplies available to meet this requirement.

The aim of the present work was to show that cottonseed flour introduced into rehabilitation diets is not nutritionally harmful. The cottonseed flour obtained from glandless seeds contains traces of gossypol. As gossypol is known to have pathological hepatic and testicular actions, the effects on hepatic variables and on the histological appearance of liver and testis of diets containing cottonseed flour were compared with those without cottonseed flour. Seventy growing male Wistar rats were divided into two groups. The control group (C) received a balanced diet (200 g casein+3 g methionine/kg) for 78 d and the experimental group was fed on a low-protein diet (20 g casein+3 g methionine/kg) for 29 d. After the period of protein deprivation, the depleted rats were divided into four groups and each group was refed with a different diet, for 49 d: a balanced diet (200 g casein+3 g methionine/kg; rC), maize–soya-bean flour–milk (60:30:5, by wt; MSM), maize–cottonseed flour–milk (60:30:5, by wt; MCM) or rice–cottonseed flour–milk (60:30:5, by wt; RCM). Each diet was supplemented with a vitamin mixture (10 g/kg) and a salt mixture (40 g/kg). In the liver, protein, total lipid, fatty acid composition and nucleic acid contents were determined after 29 d of protein deprivation and after 2, 14, 29, 49 d of refeeding. The refeeding of rats with either diet MSM or RCM promoted a higher growth than that with diet MCM or diet rC. In all groups, a progressive decrease in relative liver weights with age was observed. The highest values were obtained with diets rC and MSM. After 49 d of refeeding, the lowest values for lipid, DNA and protein: RNA and the highest values for RNA and RNA:DNA were obtained with the cottonseed diets (MCM and RCM). Rats fed on the cottonseed-flour diets for a 49 d period after severe protein malnutrition showed no change in size or shape of their hepatocytes compared with those obtained with the control casein diet, and all stages of spermatogenesis occurred normally and spermatozoa were accurately formed. Therefore, our findings show that a low level of gossypol administrated during 49 d, even to an organism weakened by protein malnutrition, does not affect hepatic variables and the histological appearance of liver and testis.

1. The dietary intake of male mice from a line selected for high body-weight was restricted to 60% by weight of the ad lib. intake of the control litter-mates between days 21 and 42 post partum.

2. One group was killed and compared with controls at 42 d of age. A further group then resumed ad lib. feeding. Mice which had regained the control body-weight by 61 d of age were killed and also compared with controls.

3. Muscle weight, fibre length, sarcomere length, sarcomere number per fibre, actin length and myosin length were measured in the biceps brachii and tibialis anterior muscles.

4. Muscle weight, fibre length and the number of sarcomeres per fibre were significantly reduced in both muscles following dietary restriction, but regained their control values following a resumption of normal feeding. The other indices remained unchanged throughout the study.

5. The pattern of fibre length changes, due entirely to alterations in sarcomere number, is similar to that reported previously during growth, senescence and immobilization and following selection for high and low body-weights.

Dairy fat is rich in SFA such as palmitic acid (16:0) but low in linoleic acid (18:2n-6). The natural carbon 13 enrichment (δ13C) of 16:0 is higher in dairy fat than in most of the food supply. In adults, serum levels of pentadecanoic acid (15:0) and heptadecanoic acid (17:0) are recognised as biomarkers of dairy intake. In adolescents, no study has evaluated serum fatty acid levels or δ13C in response to chronic dairy consumption. The objectives of this study were to evaluate whether increased dairy product consumption can modulate (1) serum fatty acid levels and (2) 16:0 δ13C in adolescents with overweight/obesity who followed a 12-week weight management programme. This secondary analysis of a randomised control trial included two groups of adolescent females: recommended dairy (RDa; n 23) and low dairy (LDa; n 23). The RDa group was given 4 servings/d of dairy products while the LDa group maintained dairy intakes at ≤ 2 servings/d. Blood was sampled before and after the intervention. Lipids were extracted and separated, and fatty acids were quantified by GC. Isotope ratio MS was used to assess 16:0 δ13C. There were no group differences on serum changes of 15:0 or 17:0. Within TAG, 18:2n-6 was lowered by 7·4 % only in the RDa group (P = 0·040). The difference in delta 16:0 δ13C between the LDa and RDa groups did not reach statistical significance (P = 0·070). Reductions in serum 18:2n-6 by dairy consumption could have positive health implications, but more studies are needed to confirm this assertion.