Current theoretical concepts of gerontological dietetics have been analysed. Elaboration of rational nutrition patterns for the old should rest on the age-specific metabolic and functional changes in the organism. A possibility of influencing the acid-base balance of the blood, immunity, and intestinal microflora by means of a goal-oriented diet has been demonstrated. The alimentary factors, which have been revealed during studies of actual nutrition patterns in the regions of high-longevity (Abkhazia and Azerbaidjan) and low-longevity (Ukraine), and which may have some relevance to longevity, are discussed. The necessity of the nutrition rationalization for the old has been grounded, which may be achieved by lowering food caloric protein and fat contents, by increasing carbohydrate and fibre proportions, and by saturating food with the nutrients capable of geroprotective effects, which is possible when milk and vegetable products are predominant in the diet and new food products for the old are included in it.