Changes in food intake in the elderly.

Decreases in body weight are common in elderly individuals (over 70 years of age) who do not eat enough to meet energy demands. Age related reduction in energy intake is largely a physiologic effect of healthy aging and reveals itself with a loss of eating need and pleasure. This reduction intake may predispose to the harmful anorexic effect of psychological, social and physical problems that become increasingly frequent with aging. Age-related anorexia may be defined as an unintentional decline in food intake, that begins near the end of life; it represents a sign of a failure to preserve steady state levels of body weight and energy stores. Absence of obvious pathology associated distinguishes the physiological anorexia of aging (due to appetite, taste and olfactory acuity, dental status, physical activity,…) from pathological anorexia, a phenomenon characterised by increased resting energy expenditure, elevated cytokines and muscle and fat wasting related to disease (acute and chronic diseases, disability,…) A third form of anorexia in elderly is related to environment (age, sex, income, cooking facilities, retirement/leisure time, education, distance to food store, availability of transportation, social activity, self-esteem, symbolism of food, mental awareness,…) and iatrogenic conditions (use of drugs,…).