[Assessment of the protein requirement in old age (author's transl)]

Studies have been carried out on the age-specific peculiarities of the distribution in the metabolic sphere of radioactive carbon-2-14C-glycine, on the intensity of its utilization in the synthesis of tissue and serum proteins, lipids and glycogen, and on the excretory level in the urine of radioactive products of metabolism in young and old animals adapted to portions of food containing different amount of protein. As has been shown, the intensity of the assimilation and dissimilation phases of the protein metabolism decreases with age. An increase in the protein content of the diet fed to old animals has no activating effect on the protein synthesis; it results in an increased utilization of the metabolic products in the biosynthesis of lipids, but not glycogen which fact is characteristic of an optical nutrient ratio. The consumption of foodstuffs influences both the state of health and the life-span of the organism. The literature contains a great many data on the unfavourable influence of various food ingredients on the organism (1-3). It has been pointed out in this context that age-related food and energy requirements play an important role also in the rational nutrition of the aged, and that an adequate limitation of the fat and carbohydrate content of the food rations of old people is not inconsistent with the above statement.