Abstract
Appetite is controlled by a complicated system with hunger and satiety signals interacting in complex pathways both peripherally and centrally. Insulin, leptin and ghrelin are key hormonal regulators of food intake. Ghrelin enhances appetite while leptin is a satiety signal. A novel peripheral regulator of food intake, peptide YY3–36, is released from the gastrointestinal tract postprandially. In this review old and new peripheral signals and their interaction in the control of food intake are briefly discussed.