Participants will be required to fast overnight prior to each visit. An intravenous line will be placed at 0800, all subjects will be fed a standard breakfast (35% fat, 15% protein, and 50% carbohydrate) consisting of 25% of estimated caloric needs for weight maintenance, which they will consume in 30 minutes or less. Blood will be taken beginning 30 minutes before the standardized meal, then at time 0, then 30, 60, 90, and 120 minutes after the meal for total ghrelin, pancreatic polypeptide, PYY3-36, active GLP-1, insulin, glucagon, leptin, oxyntomodulin, and glucose. An extra fasting sample will be obtained for lipids and total adiponectin. Three-quarters of a cup (148 mL) of blood will be drawn for analysis at each visit. Additionally, subjects will be asked to complete a Visual Analog Scale (VAS) three times during each research visit by placing a single vertical mark across a 100 mm in length line, with words anchored at each end, expressing the most positive and the most negative rating, to assess hunger, satiety, and fullness. Each visit will last approximately 4 hours.