Pilot Study to Test Dietary Fat Delivery

This study includes two parts, a baseline study and a three-week dietary study. The baseline study will be performed to test how the body absorbs and stores meal fat after a meal. In the three-week dietary study, the subjects will consume only the meals provided by the investigators for three weeks before the tests, and then participate in a hospital stay. The three-week dietary study is to test the chronic effect of a high fat diet on how body absorbs and stores the fat.

Inclusion criteria

• Lean/insulin sensitive (n=10, BMI ≤ 24 kg/m2 and glucose infusion > 4.0 mg/min))
• Overweight/obese insulin resistant (n=10, BMI 26-35 and glucose infusion < 4.0 mg/min)
• 30-50 years of age
• Men and pre-menopausal women

Exclusion criteria

• Insulin resistance is defined by insulin clamp as the rate of glucose infusion ≤ 4.0 mg/min.
• BMI over 35 kg/m2
• Abnormal thyroid function, kidney or liver disease
• Uncontrolled hypertension, or occasional or regular smoker, use of medications or supplements that interfere with lipid, protein, or carbohydrate metabolism
• Pregnancy (urine test), breast feeding an infant, or anemia
• Alcohol intake: Males >140 g/week, Females > 70 g/week.
• Fasting plasma triglycerides >300 mg/dL. Extreme hypertriglyceridemia could be due to either elevations in very low-density lipoproteins or chylomicrons, either of which would impair our ability to resolve dietary metabolic processes.
• Need to consume acetaminophen-containing medications on a regular basis.