 At the conclusion of the 2 mo treatment phase, patients will enter the laboratory at the Columbia University Medical Center for a 1-d period. Patients will arrive at 0800 h and will remain in the laboratory for the following 24 h. Blood will be sampled in the fasting state in the morning, and will be assayed for select appetite-regulating hormones leptin, ghrelin, adiponectin, glucagon-like peptide-1. We will al,so assess body composition. During the laboratory day, ad libitum EI will be measured for each treatment phase. Breakfast, lunch, snack, and dinner will be served at the standard times, but each meal item will be served in excess such that patients will be able to eat as much or as little of each food as they choose. Additional snack choices will also be freely available during the wake episode. 