What are the dietary energy needs of elderly adults?

The energy requirements of healthy elderly men were investigated by measuring total energy expenditure (TEE), body composition and resting energy expenditure (REE), using 2H2(18)O techniques and indirect calorimetry during ten days when a weight maintaining diet was consumed. Values for TEE/REE (1.75 +/- 0.05, s.e.) were significantly higher than the recommended dietary allowances (RDAs) for energy in this age group, as were previously reported values for TEE/REE in a group of young men in the same experimental protocol. There was a significant negative association between TEE/REE (a physical activity indicator) and body fat mass. Combining data from the elderly men in this study and the young men studied previously, age and TEE/REE together accounted for 73% of the variation in body fat mass between individuals. These results lend additional weight to the suggestion that the current RDAs for energy may significantly under-estimate usual energy requirements. They also indicate that the low levels of energy expenditure suggested by the RDAs may favour unnecessarily high levels of body fat mass and that increased levels of energy expenditure are desirable.