Food and Circadian Timing

The goals of this study are to uncover the influence of diet on the human circadian timing system. The protocol is a 46-day (28 outpatient days, 18 inpatient days over two 9 day visits) randomized cross-over study designed to elucidate the speed of entrainment in response to a high-fat diet.

Inclusion Criteria: * Healthy, lean men and women Exclusion Criteria: * Major dietary restrictions (such as entirely dairy-free and/or meat-free diets) * A body mass index (BMI) of 18.5\< \[BMI\] \< 24.9 kg/m\^2 and a waist circumference \135 mmHg or diastolic blood pressure\>85 mmHg; 3. Fasting blood glucose ≥ 100 mg/dL; 4. Triglycerides ≥ 150 mg/dL. * Pre-Diabetes/Diabetes * Hypertension * Disorders of the Respiratory System * Disorders of the Kidney and Urinary Tract * Infectious Diseases * Disorders of the Gastrointestinal System * Disorders of the Immune System * Disorders of the Hematopoietic System * Neoplastic Diseases * Endocrine and Metabolic Diseases * Neurologic Disorders * Subjects must not be currently participating in another research study that would influence their safe participation in our study