Inclusion Criteria:  Premenopausal females Ages 18-50 Full Mexican or Filipino ancestry only BMI 19-40 Fluent in English Right-handed  Exclusion Criteria:  Co-Morbidities including but not limited to:  Type I diabetes (insulin dependent) Vascular disease Drastic weight loss (more than 10lbs over the preceding 2months) Frequent Strenuous exercise (i.e. marathon runners/heavy weight lifting) Abdominal surgeries including weight loss surgery, or partial/complete resection of the stomach or bowel Untreated thyroid disease Neurological disease Major medical condition that may put the subject at risk or interfere with data collection as determined by the PI/MD Chronic pain Diagnosed DSM IV active psychiatric illness including eating disorders. Must not be active or present for at least 2 years. Use of medications known to affect hunger, satiety, and/or appetite. Unable to safely participate in the MRI (claustrophobia, presence of devices affected by MRI such as pacemakers, neurostimulators, or any metallic foreign body, etc.) Pregnant, lactating, postpartum less than 6mo Women of childbearing age who are not practicing birth control or are planning to get pregnant during the study. Body weight at enrollment greater than 400lbs due to weight restrictions on the MRI table Use of oral/IV antibiotics within the last 3 months Use of probiotics in the last month Heavy use of tobacco, alcohol, and/or drug use/abuse Significant change in usual diet and/or weight loss of more than 10lbs in the last 2months Refugees or recent immigration of less than 2 years in the USA. Temporary workers/visitors/students Recent international travel if more than 3 weeks within the last 3 months.  Use of the following medications is exclusionary:  Opiates/narcotics Chronic daily use of high dose OTC analgesics Anti-seizure medications Medications for appetite suppression Chronic use of laxatives/antidiarrheals, medications affecting GI motility Insulin Bile Acid Sequestrants Centrally acting medications that will interfere with the neuroimaging testing Thyroid replacement medications (OK if stable for at least 3mo) Heavy use of tobacco/cannabis Heavy use of alcohol ( >7/week for women) Antidepressants (5HT3's/Tricyclics) (OK if stable for at least 3mo)