Investigation of Neuro-hormonal Mechanisms of Hunger, Fullness and Obesity.

Inclusion Criteria: * Males and females 18 to 65 years of age. * Obese Subjects with BMI \>40. * Normal weight subjects with BMI = 18.5-24.9 Exclusion Criteria: * Age younger than 18 years and over 65 years of age. * Current use of narcotics or morphine * Previous gastric surgery * Presence of the following disorders that are known to cause functional gastric stasis syndromes: Diabetes Mellitus, Hypothyroidism, Progressive Systemic Sclerosis, Systemic Lupus Erythematosus, Dermatomyositis, Familial Dysautonomia, Pernicious Anemia, Bulbar poliomyelitis, Amyloidosis, Gastric Ulcer, Post-vagotomy, Tumor-associated gastroparesis, Fabry disease, Myotonic Dystrophy, Post-operative ileus, Gastroenteritis. * Presence of the following disorders that are known to cause delayed gastric emptying: peptic ulceration, recent surgery, pyloric hypertrophy, post-radiotherapy, ileus, anorexia nervosa, acute viral infections. * Presence of the following disorders that are known to cause rapid gastric emptying: Pyloroplasty, Hemigastrectomy, Duodenal ulcer, Gastrinoma (Zollinger-Ellison syndrome), Hyperthyroidism * Current use of Thyroxine as it is known to cause rapid gastric emptying * Current or recent (within the last 2 weeks) use of anti-spasmodics or pro-kinetic medications. * Current use of Hyperalimentation * Presence of any metabolic disorder, such as: hyperglycemia, acidosis, hypokalemia, hypercalcemia, hepatic coma or myxedema. * Current use of estrogen or progesterone * Current use of the following drugs that are known to delay gastric emptying: Nifedipine, beta-adrenergic agonists, Isoproterenol, Theophylline, Sucralfate, anticholinergics, Levodopa, diazepam, tricyclic antidepressants, phenothiazine, Progesterone, oral contraceptives, alcohol, nicotine, opiates. * Allergy to eggs or wheat. * Pregnancy.