Because of the physiologic importance of maintaining energy stores, voluntary weight loss is difficult to achieve and and metabolism are regulated by an intricate network of neural and hormonal factors. The hypothalamic feeding and satiety centers play a central role in these processes (Chap. 74). Neuropeptides such as corticotropin-releasing hormone (CRH), α-melanocyte-stimulating hormone (α-MSH), and cocaine- and amphetamine-related transcript (CART) induce anorexia by acting centrally on satiety centers. The gastrointestinal peptides ghrelin, glucagon, somatostatin, and cholecystokinin signal satiety and thus decrease food intake. Hypoglycemia suppresses insulin, reducing glucose utilization and inhibiting the satiety center. .
