OBJECTIVE: To investigate whether the substitution of ®sh oil for visible fats in a control diet (52% carbohydrates, 16% protein, 32% fat; P:S 0.2) in¯uences body fat mass and substrate oxidation in healthy adults. DESIGN: Six volunteers (5 men; 23 AE 2 y; BMI: 21.9 AE 1.6) were fed a control diet (C) ad libitum during a period of three weeks and, 10±12 weeks later, the same diet where 6 g/d of visible fat were replaced by 6 g/d of ®sh oil (FO) for another three weeks. RESULTS: Energy intakes (IKA-calorimeter) were unchanged. Body fat mass (Dual-energy X-ray absorptiometry) decreased with FO (70.88 AE 0.16 vs 70.3 AE 0.34 kg; FO vs C; P`0.05). When adjusted for lean body mass (Ancova), resting metabolic rate (indirect calorimetry) was unchanged. Basal respiratory quotient decreased with FO (0.815 AE 0.02 vs 0.834 AE 0.02; P`0.05) and basal lipid oxidation increased with FO (1.06 AE 0.17 vs 0.87 AE 0.13 mg kg 71 min 71 ; P`0.05). CONCLUSION: Dietary FO reduces body fat mass and stimulates lipid oxidation in healthy adults.

Parameters used are predictors for short-term in-hospital mortality of elderly patients hospitalized in an acute medical unit. The lean body mass is preferentially mobilized for energy during hospitalization.

This study examines the effect of the substitution of 6 g/day of fish oil in a saturated diet on glucose and fructose metabolism in healthy humans. Five subjects were submitted to two 3-wk controlled-diet periods (polyunsaturated/saturated = 0.21). During one period, 6 g/day of fat used for dressing were replaced by 6 g/day of fish oil [1.1 g/day of 20:5 (n-3) fatty acids and 0.7 g/day of 22:6 (n-3) fatty acids]. At the end of each period the subjects ingested a 1 g/kg fructose or glucose load 2 days apart. Plasma glucose fluxes were traced with the use of deuterated glucose and [U-13C]glucose. Substrate oxidation was measured by indirect calorimetry. Fish oil induced a 4% increase in basal and postload glycemia and a 40% decrease in insulinemia, whereas plasma C-peptide remained unaffected. Glucose fluxes were unaffected by fish oil, but carbohydrate (CHO) oxidation was reduced (fructose: 55.5 +/- 4.1 vs. 62.9 +/- 3.6 g/6 h; glucose: 36.7 +/- 4.7 vs. 50.5 +/- 4.7 g/6 h; all P < 0.05). Lipid oxidation was increased 35% by fish oil after both CHO loads. Nonoxidative glucose disposal was increased by fish oil (fructose: 9.4 +/- 2.5 vs. 2.9 +/- 1.1 g/6 h; glucose: 28.3 +/- 5.1 vs. 14.4 +/- 4.7 g/6 h; all P < 0.05). Fish oil could affect glucose transport and decrease CHO oxidation through the decrease in insulinemia and/or a specific effect on glycolytic pathway.

Among monosaccharides, fructose has a small hyperglycaemic effect. In order to better explain the mechanisms which cause this metabolic property, we used tracers labelled with stable isotopes (deuterated glucose and naturally 13C labelled fructose) to quantify the overall glucose appearance, the rate of appearance in plasma of the 13C glucose synthesized from fructose, and the fructose oxidation in vivo in man during a 6-h period following ingestion of 0.5 and 1 g.kg-1 fructose. Fructose had a very small effect on overall glucose appearance (NS). During the 6 h of the study, it was found that the overall glucose appearance was 0.87 +/- 0.06 and 0.89 +/- 0.06 g.kg-1 (NS). The amount of glucose synthesized from fructose was 0.27 +/- 0.04 and 0.51 +/- 0.03 g.kg-1 (p < 0.01) representing 31% and 57% of overall glucose appearance (p < 0.01); the non-fructose glucose production was 0.60 +/- 0.02 and 0.38 +/- 0.03 g.kg-1 (p < 0.05) after the 0.5 and 1 g.kg-1 load, respectively. Fructose oxidation was 0.28 +/- 0.03 and 0.59 +/- 0.07 g.kg-1 after the 0.5 and 1 g.kg-1 load respectively (p < 0.01) representing 56% and 59% of the fructose loads (NS). These data show that the low hyperglycaemic effect of fructose is explained by its very small effect on overall glucose appearance and that fructose has a sparing effect on glucose metabolism.

The relationships between essential fatty acid (EFA) composition of colostrum, mature milk, and white adipose tissue (WAT) were examined on days 5 and 30 postpartum in 24 healthy French mothers. Fatty acid composition was assessed by capillary gas chromatography. In WAT, the proportion of individual polyunsaturated fatty acids (PUFAs) did not change during lactation and was greater (18:2n-6) or lower (18:3n-3, long-chain PUFAs) than values found in colostrum or mature milk (P < 0.04). The 18:2n-6 content and the ratio of 18:3n-3 to 18:2n-6 correlated between WAT and colostrum (r = 0.52 and r = 0.57, respectively) or mature milk (r = 0.64 and r = 0.65, respectively). These relationships agree with an expected qualitative effect of WAT fatty acid composition on interindividual variability of milk parent EFA content. The decrease in the long-chain PUFA content observed from colostrum to mature milk and the concomitant occurrence of a precursor-product relationship between the linoleate and its long-chain PUFA are consistent with the mobilization of a preformed long-chain PUFA pool during early lactation.

We compared anthropometric indices in samples of elderly people aged 65 years and over living in two French areas. The samples were divided into four age-groups (65-69,70-74,7579 and over 80 years). We observed interregional differences in women aged 65-69 years and in men aged 65-74 years. Weight and anthropometric variables related to body fat percentage and to muscle mass showed a decline with age as already reported by others. We established anthropometric percentile values according to sex in pooled subjects when no integrated difference was found. The 50th percentile of arm circumference, muscle arm circumference and triceps skinfold was higher, and the 50th percentile of body mass index was lower than the one reported for the same indices from an elderly Welsh population. Our results show that an interregional difference in anthropometric indices exists in the elderly. The differences which are observed between our results and those reported from a British population emphasize the importance of establishing local values for the elderly population.

This amino acids solution is efficaciously utilized for protein synthesis in CAPD patients with no effect on protein breakdown. The concomitant ingestion of a carbohydrate-lipid meal inhibits protein breakdown and reinforces a positive effect of the amino acids solution on protein balance.

The relationships between essential fatty acid (EFA) composition of colostrum and white adipose tissue (WAT) were examined on day 5 after delivery in 69 healthy women. Fatty acid composition was assessed by capillary gas chromatography, and 33 fatty acids were detected in colostrum and in WAT. Total polyunsaturated fatty acid (PUFA) content was similar in colostrum and in WAT (15.7 +/- 3.1% and 16.1 +/- 3.8%, respectively), but long-chain PUFA content was higher in colostrum than in WAT (2.9 +/- 0.6% and 1 +/- 0.2%, respectively; P less than 0.001). The concentrations of linoleic acid were significantly correlated between colostrum and WAT (r = 0.77, P less than 0.0001). No correlation was found for alpha-linolenic acid. The relationships between long-chain PUFA composition of colostrum and WAT suggested that individual factors along with tissue specificity of the mammary gland are involved in either the capacity of desaturating and chain-elongating pathways and/or incorporation of long-chain PUFAs into colostrum.