Studying the Hedonic and Homeostatic Regulation of Food Intake Using Functional MRI

Inclusion Criteria: * BMI 18-25 kg/m\^2. * Weight stable for 3 months prior to study entry. * For females: study days will be scheduled during the follicular phase of their menstrual cycle (i.e., the first 13 days (about 2 weeks) of the cycle). * Able to provide written informed consent prior to any study procedures and be willing and able to follow study procedures.. * Ability to perform light to moderate physical activity. Exclusion Criteria: * Any contraindication for MRI scanning. * Any history of childhood (\> 95th percentile) or adult obesity (BMI \>30 kg/m\^2). * Claustrophobia. * High intensity training or physical activity. * Any contraindication for intragastric balloon insertion. * Any allergies to the study meals. * Any history of eating disorder. * Any substance abuse disorder (including alcohol and tobacco). * Any history of psychiatric disorders. * Any cardiovascular, endocrine, pulmonary, neurological, or gastrointestinal comorbidities. * Pregnancy or nursing. * Any history of bariatric surgery or endoscopic bariatric procedure. * Use of any medication or supplement that alters appetite. * Patient has a known history of any condition or factor judged by the investigator to prevent participation in the study or which might hinder study adherence.