Patient description: The patient is a 57-year-old man with abdominal pain and vomiting. The pain started gradually about 20 hours ago in the epigastric and periumbilical regions, radiating to his back. He drinks around 60 units of alcohol per week and smokes 22 cigarettes per day. He is healthy with no history of allergies or using any medications. His family history is positive for type 2 diabetes (his father and sister). He lives alone and has no children. The abdomen is tender and soft. His bowel sounds are normal. His heart rate is 115/min and blood pressure 110/75 mmHg. The lab results are remarkable for leukocytosis (19.5), urea of 8.5, high CRP (145), high amylase (1200) and Glc level of 15. Cross-sectional imaging was negative for obstructive pancreatitis.

Clinical trial eligibility criteria: eligible ages (years): 18.0-65.0,  Obesity Overweight and obese adults (≥30 kg/m^2 or ≥27 kg/m^2 with an obesity-related co-morbidity) Subjects residing within 125 miles of Mayo Clinic in Rochester, Minnesota Healthy individuals with no unstable psychiatric disease and not currently on treatment for cardiac, pulmonary, gastrointestinal, hepatic, renal, hematological, neurological, or endocrine (other than hyperglycemia type 2 diabetes mellitus on metformin) disorders The investigators plan to recruit equal proportions of men and women Women of childbearing potential will be using an effective form of contraception, and have negative pregnancy tests within 48 hours of enrollment and before each radiation exposure. In addition, since liraglutide 3.0 mg is classified as Pregnancy Category X, monthly urine pregnancy testing will be performed in any female participant with childbearing potential Subjects must have the ability to provide informed consent before any trial-related activities  Weight exceeding 137 kilograms (safety limit of camera for measuring gastric volumes) Abdominal surgery other than appendectomy, cholecystectomy, Caesarian section or tubal ligation Positive history of chronic gastrointestinal diseases, systemic disease that could affect gastrointestinal motility, or use of medications that may alter gastrointestinal motility, appetite or absorption, e.g., orlistat Patients with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia-type 2 Patients with a past or current history of pancreatitis, gallstones, history of alcoholism, blood triglyceride levels >500 mg/dL Significant untreated psychiatric dysfunction based upon screening with the Hospital Anxiety and Depression Inventory (HAD), a self-administered alcoholism screening test (AUDIT-C), and the Questionnaire on Eating and Weight Patterns (binge eating disorders and bulimia). If such a dysfunction is identified by a HAD score >11 on either the Anxiety or Depression subscales, or difficulties with substance or eating disorders, the participant will be excluded and given a referral letter to his/her primary care doctor for further appraisal and follow-up Intake of any medication (except multivitamins), within 7 days of the study. Exceptions are birth control pill, estrogen replacement therapy, thyroxin replacement therapy and any medication administered for co-morbidities as long as they do not alter gastrointestinal motility including gastric emptying (GE) and gastric accommodation. For example, statins for hyperlipidemia, diuretics, β-adrenergic blockers, Angiotensin Converting Enzyme (ACE) inhibitors and angiotensin antagonists for hypertension, and metformin for type 2 diabetes mellitus or prediabetes are permissible. In contrast, resin sequestrants for hyperlipidemia (which may reduce GE and reduce appetite, α2-adrenergic agonists for hypertension, or other glucagon-like peptide-1 receptor agonists (GLP-1) receptor agonists (exenatide) or amylin analogs (pramlintide) are not permissible because they significantly affect GE and/or gastric accommodation Delayed gastric emptying at 2 and 4 hours Hypersensitivity to the study medication, liraglutide Participate in highly intense physical activity program that could potentially interfere with study interpretation