Energy expenditure at age 73 and 78--a five year follow-up.

There is limited knowledge concerning the energy turnover and energy requirements of the elderly. The aim of this study was to measure resting metabolic rate (RMR) and total energy expenditure (TEE), and to define activity energy expenditure (AEE) and physical activity level (PAL) in 11 78-year-old individuals. A further aim was to compare these measures with the same measures taken from the 11 subjects at age 73 years. Total body water (TBW) averaged 30.8 kg (SD 3.2) at age 73 and 28.8 kg (SD 3.5) at age 78 years ( p<0.01). RMR was measured with a ventilated-hood system and averaged 5.60 MJ/day (SD 0.66) at age 73 and 4.77 MJ/day (SD 0.32) at 78 years ( p<0.001). TEE, measured using the doubly labeled water method, averaged 9.64 MJ/day (SD 1.10) at age 73 and 8.30 MJ/day (SD 1.45) at 78 years ( p<0.05). AEE averaged 4.04 MJ/day (SD 0.44) at age 73 and 3.53 MJ/day (1.13) at 78 years (ns). PAL averaged 1.74 at both ages. TBW, TEE, and RMR decreased, whereas AEE and PAL did not change substantially during the 5-year follow-up. The PAL values indicated a physically active lifestyle for the age group.

Resting energy expenditure, activity energy expenditure and total energy expenditure at age 91-96 years.

There is a limited knowledge concerning energy requirements of the elderly, especially the oldest old (> 80 years). Energy requirements should be estimated from measurements of energy expenditure. For this purpose twenty-one free-living individuals (eight males, thirteen females) aged 91-96 years living in Göteborg, Sweden were studied. Total body water (TBW) measured by the doubly-labelled-water (DLW) technique was 29.5 (sd 5.4) kg in females and 35.6 (sd 4.3) kg in males. TBW measured using bioelectric impedance (BIA) was 31.6 (sd 6.4) kg in females and 42.0 (sd 7.4) kg in males. The mean difference between TBW measured by BIA and that measured by DLW was 3.54 (sd 3.6) kg (P = 0.0002). Resting metabolic rate (RMR) was measured using a ventilated-hood system and averaged 5.36 (sd 0.71) MJ/d in females (n 12) and 6.09 (sd 0.91) MJ/d in males (n 8). Difference between measured RMR and predicted BMR (n 20) was 0.015 (sd 0.86) MJ/d (NS). Total energy expenditure (TEE) measured by DLW averaged 6.3 (sd 0.81) MJ/d in females and 8.1 (sd 0.73) MJ/d in males. Activity energy expenditure (TEE - RMR), thus including diet-induced thermogenesis (DIT), averaged 0.95 (sd 0.95) MJ/d in females (n 12) and 2.02 (sd 1.13) MJ/d in males. Physical activity level (TEE/BMR) averaged 1.19 (sd 0. 19) in females and 1.36 (sd 0.21) (P = 0.08) in males. If DIT is assumed to be 10 % of the TEE, energy spent on physical activity will be very low in this population.