Inclusion Criteria:

• * Body Mass Index 22 to 35 kg/m2
• * Prediabetic (HbA1c 5.7% to 6.5%) or hyperinsulinemic (fasting insulin ≥12 µIU/mL) but non-diabetic (fasting glucose \<126mg/dL and HbA1c \< 6.5%) ; or normal control (fasting insulin \<10 µIU/mL, fasting glucose \<100 mg/dL, and HbA1c \< 5.7%)

Exclusion Criteria:

• * Pregnancy or lactation within the past six months
• * Type 1 or 2 diabetes mellitus
• * History of liver disease or aspartate aminotransferase (AST) and alanine aminotransferase (ALT) 2x the upper limit of normal (ULN);
• * Fasting triglyceride or total cholesterol levels above 95th percentile for age and sex;
• * Hemoglobin or hematocrit below the lower limit of normal for sex;
• * Report of hepatitis or HIV infection;
• * History of cancer, use of any anti-diabetic medications or hypolipidemic agents in the past six months;
• * History of surgical procedure for obesity;
• * Self-reported change in body weight \>5% in the past six months;
• * History of other conditions known to affect insulin sensitivity and lipid metabolism;
• * Known intolerance to acetaminophen or components of the liquid test meals.