The net effect is anorexia, with the inhibition of food intake, body weight loss, delayed gastric emptying and functions, the stimulation of gluconeogenesis, glycogenolysis and ketogenesis as sources of metabolic fuel, which if unabated leads ultimately to cachexia. The use of antagonists and the removal of stress or noxious stimuli experimentally test different pathways of this dynamic metabolic picture. Several studies have demonstrated important progress towards our understanding of the central mechanisms involved in anorexia and weight loss, which we summarize in this review.

a Department of Medicine, Gastroenterology Division, and b Surgical Metabolism and Nutrition Laboratory, Neuroscience Program, Department of Surgery, University Hospital, SUNY Upstate Medical University, Syracuse, New York, USA; c Second Department of Clinical Molecular Medicine, Kobe University Graduate School of Medicine, Kobe, Japan; and d Department of Statistics, Syracuse University, Syracuse, New York, USA