[Control of food intake].

The decisions of an individual about his food intake depend upon a variety of internal and external signals. The present contribution describes the physiological mechanisms controlling food intake to preserve body composition and performance. Centers within the hypothalamus including their connections to higher and lower structures within the central nervous system, especially to the limbic system, are involved in the control a food intake. Neuropeptides and neurotransmitters usually initiate more complex actions including the search for food and satiety phenomena. Their production and release are influenced by food consumption as well as intake of specific nutrients, sensorial perceptions, and a variety of other factors. Vagal reflexes and gastro-intestinal hormones, fat cell size, physical activity, and thermogenesis also influence perceptions of hunger and satiety. A model satisfactorily describing the interactions between all known factors that control food intake is still missing. The path from hunger to satiety could be described as sequences of cascades similar to the various steps in blood clotting. Control of food intake during early life dependably relies on energy requirement, and can be utilized for ad-libitum feeding. Obesity and anorexia nervosa are manifestations of disturbed control over food intake. Neuropharmacology offers several therapeutic approaches to specific conditions. However, by and large abnormalities of food intake control have to be treated by behavioral modification.