[Nutrition in old age-key to maintaining functionality and quality of life].

In persons beyond age 70 a decrease of muscle mass and an increase of fat mass are regularly observed. These changes of body composition constitute a relevant predisposition for the imminent loss of functionality and autonomy in older age. In this context adequate nutrition and the prevention of malnutrition play an essential role. As the older population is extremely heterogeneous with regard to the velocity and extent of aging processes and also with regard to comorbidities, recommendations for adequate nutrition have to be individualized. Even voluntary loss of weight may be critical as it may accelerate the development of sarcopenia. As a general rule periods of fasting should be avoided. This is especially true with regard to inadequate caloric intake in the course of acute and chronic diseases. Therefore, weight measurements should be performed regularly in older persons, which would allow early diagnosis and treatment of malnutrition. In comparison to younger adults a higher protein intake of 1.0 g/kg bodyweight is recommended for older persons, as this may slow their decline of muscle mass and muscle function. If sarcopenia is already present, the recommended protein intake is raised towards 1.2 g/kg bodyweight. While restrictive diets may be detrimental in older persons, healthy diets like the Mediterranean diet may support the preservation of muscular and cognitive function.