Clinical Research Directory

Inclusion Criteria: * Men or Women * Age 50-79 years (only postmenopausal women \> 2 years) * Body mass index (20-25 kg/m2; and 30-40 kg/m2)\* Exclusion Criteria: * Diagnosed with, active, or history of liver cirrhosis, chronic or persisting hepatitis * Diagnosed with, active, or history of cancer * History of gastrointestinal disease or surgical procedure for weight loss. * Diagnosed with immune diseases, type 2 diabetes, pancreatitis, or infectious diseases * Any surgery in the past 6 months * Currently using or have used antibiotics continuously \> 3 days in the past 3 months * Regular use of medications for that affect the gastrointestinal tract, cholecystitis, urinary tract infection, severe organic diseases including coronary heart disease, myocardial infarction, infectious diseases including pulmonary tuberculosis and AIDS * Known allergy or intolerance to any ingredients in the dietary intervention program * Alcohol or illicit drug abuse * Current Smoker or have quit smoking in the past 3 months * Recent colonoscopy (within the previous two months) * Inability to follow any of the experimental diets (including low or high fat diet) or to perform the collections required for this study * Participants will also be excluded if they have extreme dietary habits, extreme levels of physical or athletic activity, or by changes in body weight \>5 lbs. during the last 6 months * Uncontrolled hypertension or uncontrolled hyperlipidemia in abnormal ranges. * Participation in another clinical research trial that may interfere with the results of this study. * As needed, BMI (kg/m2) will be adjusted accordingly for Asian lean and obese definitions