[Changes in the energy needs of the elderly: an often encountered cause of nutritional deficiencies and frailty].

Changes in the body composition of elderly people and diminished physical activity reduce the energy requirement and the daily energy intake. It is especially frail elderly people who run an increased risk of a poor nutritional condition which further enhances fragility. Frailty is often defined as the state of reduced physiologic reserve associated with increased susceptibility to disability. In frail elderly people energy requirement is often reduced. Studies have shown that when energy intake falls below a level of about 6.3 MJ, it is hard to obtain a diet with a sufficient supply of minerals and water soluble vitamins. It is especially the daily intake of vitamins of the B complex and of vitamin C that then prove insufficient. In addition, immobile elderly and elderly of 75 years and older are at risk for an inadequate vitamin D status. An adequate diet is one of the factors that may prevent frail health. Screening lists have been developed to quickly obtain information about the nutritional status of older adults. However, these lists still have to be adapted to the Dutch dietary pattern. Currently, a change of the body weight is the best warning of insufficient nutrition.