Many methods and techniques have accumulated a considerable mass of data about the mechanisms which control food intake and energetic loss. After a presentation of the main experimental approaches in this respect, the most relevant signals sent by peripheral organs to the central nervous system are presented: Glucose, triglycerides; from adipocytes: Leptin; from pancreas: Insulin, pancreatic polypeptide, amylin, enterostatin; from digestive tract: Ghrelin, cholecystokinin, peptide Y Y 3-36. Then are considered, especially at the hypothalamic level, their interpretation by neurones whose transmitters are either neuropeptides such as: Neuropeptide Y, Agouti Related Peptide, Cocaine/Amphetamine Regulated Transcript, Melanin Concentrating Hormone, alpha Melanocyte Stimulating Hormone, orexins/hypocretins, octadecaneuropeptide, nociceptin/orphanin FQ, opioid peptides, Interleukin 1, galanin, urocortin 2, Neurotrophic ciliary factor, or monoamines such as: Glutamate, dopamine, Norepinephrine, serotonine, GABA, histamine, acetylcholine. In a last part are considered the likely relationships existing between feeding, pleasure and addiction, centered on dopamine transmission in the nucleus accumbens. After this brief synopsis one should not be surprised that this so complex system which regulates feeding may be affected by various disorders; however one may be amazed by such a scarcity of drugs to influence it; in any case, many new pharmacological strategies can be expected in the future.