Effects of the GLP-1 Exenatide on Satiety in Lean and Obese Women

Obesity is a major health problem in the US and many Western countries, with more than half of the population being overweight or obese. Yet, despite intense research efforts into the mechanisms underlying obesity and into the development of novel pharmacologic interventions, bariatric surgery, including gastric bypass surgery is the only successful treatment for severe obesity. Mimicking one of the effects of bariatric surgery, e.g. the increased secretion of glucagon-like peptide 1 (GLP-1) could be an effective strategy against obesity. Obese individuals may be more sensitive to the rewarding aspects of food and less responsive to signals from the gut about actual energy needs. Using functional MRI scanning the investigators plan to examine the effect of Exenatide (a GLP-1 analog known to reduce caloric intake and produce weight loss in both obese and lean individuals) on activity within brain regions/networks involved in reward/motivation and in regulation of energy requirements. The investigators expect the peptide to change the balance between desire to eat for pleasure and the need to eat to maintain homeostasis.