Variability In Mixed Meal Tests: Fixed Versus Adjusted to Energy Needs Caloric Dose

* INCLUSION CRITERIA: In order to be eligible to participate in this study, an individual must meet all of the following criteria: * Provision of signed and dated informed consent form. * Agreement to adhere to Lifestyle Considerations throughout study duration. * Males and females; Age \>= 18years * Healthy, as determined by medical history, physical examination, and laboratory tests. EXCLUSION CRITERIA: An individual who meets any of the following criteria will be excluded from participation in this study: * Current use of medications, dietary supplements, or alternative therapies known to alter energy metabolism. * Fasting plasma glucose \>= 126 mg/dL * Type I or Type II Diabetes Mellitus by self-report. * Hematologic disorders including significant anemia (male hemoglobin \< 13.0 g/dL or female hemoglobin \< 11.0 g/dL) * Current pregnancy, pregnancy within the past 6 months or currently lactating * History or self-report of gastrointestinal disease, including inflammatory bowel diseases (e.g. Chron s disease and ulcerative colitis), malabsorption syndromes (e.g. celiac disease), gastric ulcer (active) which may alter metabolism or absorption of study food by self-report * Evidence of alcohol abuse as defined by an 8-point score on the Alcohol consumption screening AUDIT questionnaire in adults. * Participants who report taking large doses of acetaminophen (\> 3 grams daily) who cannot stop acetaminophen 24 hours prior to and following the meal tests will be excluded from the study. * Inability to consume provided food based on a food allergy or intolerance. * Conditions not specifically mentioned above may serve as criteria for exclusion at the discretion of the investigators. * Any disorder, unwillingness, or inability not covered by any other exclusion criteria which, in the investigator s and/or team s opinion, jeopardizes the safety of the participant or others or would interfere with adherence to the protocol (such as claustrophobia). Conditions not specifically mentioned above may serve as criteria for exclusion at the discretion of the investigators.