- We will recruit eight normal weight (BMI 19 to 25 kg/m2), and eight overweight or obese (BMI 27 to 38 kg/m2), non-diabetic, healthy volunteers, who are between the ages of 30 to 55 years old. For scientific reasons it is crucial that the groups are age matched. Limiting the age range to a period of 25 years will help achieve this goal. Volunteers for these two groups must have a fasting glucose < 110 mg/dl; HbA1c < 6.0%; Hct > 34; ALT < 60; AST < 60; Alk phos < 150; sTSH < 8; Trig < 300; Chol < 250; systolic BP < 150; diastolic BP < 95; and be in good health. A medical history and physical exam will be conducted by a nurse practitioner or a medical doctor.