Development of a Novel Method to Measure Insulin Sensitivity in Humans: A Pilot Study

Inclusion Criteria: * Healthy male or female * Age 18-65 y * BMI between 20 kg/m2 and 35 kg/m2 (inclusive) * Are willing to consume pre-prepared meals * Have completed a high-dose (≥80 mIU/m2/min) euglycemic-hyperinsulinemic clamp during the last five years at Pennington Biomedical. The data from the previous PBRC clamp will be pulled and used in conjunction with data from this study. * Willing to have blood and urine stored for future use Exclusion Criteria: * Major lifestyle changes since the euglycemic-hyperinsulinemic clamp was performed (i.e. gain/lost weight, stopped smoking, began/stop exercise). * Unstable weight in the last 3 months \[gain or loss \>10 lb (or 4.5 kg)\] * Diagnosed with diabetes * Untreated hypertension and average screening blood pressure \>140/90 mmHg * Previous bariatric surgery (or other surgeries) for obesity or weight loss * Chronic use of medications affecting metabolism or sleep\* * History of neurological disease * History of cardiovascular disease, or other chronic diseases, that might affect pancreatic or glucose metabolism. * Pregnant, planning to become pregnant, or breastfeeding * Adherence to special restrained diets (e.g., low-CHO, low-fat, or vegetarian/vegan diets) over the last 3 months. \*Sporadic use of these medications is fine (however, enrollment will depend on a case-by-case basis). If taking sporadically, participants should not be taking the medication for 1-month prior to the first visit.