Figure 1. Appetite control : messengers from the gastrointestinal tract (e.g. CCK, secretin and GIP), from the pancreas (insulin) and from adipose tissue (leptin) converge upon the hypothalamus and provide a symbolic representation of the feeding status of the organism. These messages are then translated into either a food-seeking (orexic) or a fasting (anorexic) behaviour.PYY: Peptide YYCCK: CholecystokininGIP: glucose-dependent insulinotropic peptide or gastric inhibitory polypeptideGLP-1: Glucagon-like peptide-1