Shift Work, Heredity, Insulin, and Food Timing Study

Inclusion Criteria: * Male or non-pregnant female * 18-60 years * Currently employed (night shift workers and day workers), graduate students, part-time workers, or unemployed * Able and willing to give consent relevant to genetic investigation Exclusion Criteria: * Currently taking any medications for the treatment of diabetes * Currently taking medications known to affect glycemic parameters, such as glucocorticoids, growth hormone or fluoroquinolones * Pregnant, nursing or at risk of becoming pregnant * Chronic renal failure, hepatic diseases, or cancer diagnoses * Bulimia diagnosis, prone to binge eating * Eating disorder diagnosis such as anorexia, binge eating, or bulimia * With psychiatric illness, such as schizophrenia or bipolar affective disorder * Blind * History of bariatric surgery