A protein pulse-feeding pattern was more efficient than was a protein spread-feeding pattern in improving, after 14 d, whole-body protein retention in elderly women.

This study was undertaken to determine whether a pulse protein feeding pattern was more efficient than a spread pattern to improve protein anabolism in young women as was already shown in elderly women. After a 15-d adaptive period [1.2 g protein/(kg fat-free mass. d)], 16 young women (age 26 +/- 1 y) were given a 14-d diet providing 1.7 g protein/(kg fat-free mass. d), using either a pulse pattern (protein consumed mainly in one meal, n = 8), or a spread pattern (spreading daily protein intake over four meals, n = 8). Nitrogen balance was determined at the end of both the 15-d adaptive and the 14-d experimental periods. Whole-body protein turnover was determined at the end of the 14-d experimental period using [(15)N]glycine as an oral tracer. Nitrogen balance was 17 +/- 5 mg N/(kg fat-free mass. d) during the adaptive period. It was higher during the experimental period, but not significantly different in the women fed the spread or the pulse patterns [59 +/- 12 and 36 +/- 8 mg N/(kg fat-free mass. d) respectively]. No significant effects of the protein feeding pattern were detected on either whole-body protein turnover [5.5 +/- 0.2 vs. 6.1 +/- 0.3 g protein/(kg fat-free mass. d) for spread and pulse pattern, respectively] or whole-body protein synthesis and protein breakdown. Thus, in young women, these protein feeding patterns did not have significantly different effects on protein retention.

The aim of the present study was to validate against the doubly-labelled water (DLW) technique the factorial method and the heart rate (HR) recording method for determining daily energy expenditure (DEE) of elderly people in free-living conditions. The two methods were first calibrated and validated in twelve healthy subjects (six males and six females; 70.1 (SD 2.7) years) from opencircuit whole-body indirect calorimetry measurements during three consecutive days and during 1 d respectively. Mean energy costs of the various usual activities were determined for each subject using the factorial method, and individual relationships were set up between HR and energy expenditure for the HR recording method. In free-living conditions, DEE was determined over the same period of time by the DLW, the factorial and the HR recording methods during 17,14 and 4d respectively. Mean free-living DEE values for men estimated using the DLW, the factorial and the HR recording methods were 12.8 (SD 3.1), 12.7 (SD 2.2) and 13.5 (SD 2.7) MJ/d respectively. Mean free-living DEE values for women were 9.6 (SD 0 . Q 8.8 (SD 1.2) and 10.2 (SD 1.5) MJ/d respectively. No significant differences were found between the three methods for either sex, using the Bland & Altman (1986) test. Mean differences in DEE of men were -0.9 (SD 11.8) % between the factorial and DLW methods, and + 4.7 (SD 16.1) % between the HR recording and DLW methods. Similarly, in women, mean differences were -7.7 (SD 12.7) % between the factorial and DLW methods, and + 5.9 (SD 8.8) % between the HR recording and DLW methods. It was concluded that the factorial and the HR recording methods are satisfactory alternatives to the DLW method when considering the mean DEE of a group of subjects. Furthermore, mean energy costs of activities calculated in the present study using the factorial method were shown to be suitable for determining free-living DEE of elderly people when the reference value (i.e. sleeping metabolic rate) is accurately measured.Energy expenditure: Free-living conditions: Elderly Daily energy needs tend to be reduced with ageing partly because of a decrease in active cell mass (Forbes & Reina, 1976) and in duration and intensity of physical activities (Prentice, 1992). Furthermore, the large variations in daily energy needs of elderly people shown in a recent meta-analysis (Black et al. 1996) underline the heterogeneity of the population. It is important that adequate energy allowances are defined for each group of elderly people to avoid energy imbalance which could result in weight loss and a further decline in lean body mass. The latter is strategically important for physical and mental autonomy.

The energy value of NSP has been expressed as their metabolizable energy (ME) content. The aim of the present study was to determine whether differences in ME and net energy (NE) contents were similar for insoluble and soluble NSP. Nine healthy young men were offered three diets according to a Latin-square design (3 x 3) with three repetitions: diet C (control), diet B (control + 50 g sugarbeet fibre/d) and diet I (control + 50 g commercial inulin/d). After a 16 d adaptation period to NSP isolate, food intake was controlled (duplicate meal method) and faeces and urine were collected for 8 d. A period of 60 h was devoted to measurement of energy expenditure (EE) by whole-body indirect calorimetry. NSP-isolate ingestion induced significant increases in the number of defecations and stool weight resulting from increases in water, DM and microbial mass excretion. After deduction of microbial N, differences in faecal N excretion between diets were not significantly different. Urinary N excretion was slightly decreased by sugarbeet fibre or commercial inulin ingestion but the N balances for the diets were not significantly different. Diet energy, N and lipid apparent digestibilities decreased by only 1-2%. Commercial inulin was entirely fermented and fermentability of sugarbeet fibre averaged 0.886 (SD 0.117). Sugarbeet fibre and commercial inulin ME values averaged 10.7 (SD 1.2) and 13.0 (SD 2.3) kJ/g DM respectively. NSP-isolate ingestion caused significant (sugarbeet) and nonsignificant (inulin) increases in daily EE. The maintenance NE contents of sugarbeet fibre and inulin averaged 5.0 (SD 5.0) and 11.9 (SD 1.3) kJ/g DM respectively. Differences in maintenance NE contents of NSP isolates were much greater than differences in ME values.

Gender effects on energy expended during light seated activities, walking, cycling, and sleep and their consequences on daily energy expenditure (EE) were examined in 11 men and 15 women aged 66.4 +/- 7.1 yr. Two open-circuit whole body calorimeters were used for EE measurements, except for cycling, during which EE was measured separately with the use of a face mask. Lean body mass (determined using H218O dilution method), fat mass, usual physical activity level, and activity intensity (e.g., walking speed and cycling power output) were taken as covariates in the analysis of EE variations before studying gender effects. Sleeping metabolic rate (SMR) and daily EE, adjusted for differences in all covariates, were 11.2 (P = 0.005) and 8.7% (P = 0.071) lower in women than in men, respectively. No gender-related differences were found in the various physical activity EEs above SMR (e.g., gross EE-SMR) [light seated activities (P = 0.790), walking (P = 0.263), and cycling (P = 0.287)] and daily physical activity EE above SMR (P = 0.587) after adjustment for differences in all covariates. Therefore, the lower adjusted daily EE of women could be related to their lower SMR, the most reliable criterion of whole body metabolic rate.