The Effects of Increased Fructose Ingestion on FGF-21 Levels in Humans

Inclusion Criteria: * Ages 18-60 * BMI 19-25 kg/m2; 19-23 for Asian subjects * Stable weight (variation \< 3 kg within 6 months of screening visit) * Ability to give informed consent in English * Use of medically approved form of contraception Exclusion Criteria: * Fasting blood glucose \>100 * Hemoglobin A1C% \> 6.5% * Fasting triglycerides \>150 * Type 1 or type 2 diabetes mellitus diagnosed according to American Diabetes Association criteria * Coronary heart disease (history of myocardial infarction, unstable angina pectoris, or congestive heart failure) * Uncontrolled hypertension (BP \> 160/100 mmHg on or off antihypertensive medication) intravenous drug use * Recent weight loss (\> 3 kg within 6 months of the screening visit) * Gastroparesis * Inflammatory or irritable bowel disease * Malignancy treated with chemotherapy within the past 3 years * Depression or psychosis requiring hospitalization * Renal insufficiency (creatinine clearance \< 40 ml/min) * Transaminases \> 2x above the normal range * Known liver disease * Pregnancy within 6 months of the screening visit * Lactation * Failure to use medically approved contraceptive methods * History of surgery for the treatment of obesity (gastric banding, gastric bypass, gastric stapling) * Change in dose of thyroid hormone or antithyroidal medication within 3 months of screening visit * History of alcohol abuse within the past 5 years * Fructose intolerance Exclusionary medications: * Oral steroids * Metformin * Weight loss medications including nonprescription supplements