Effect of Dietary Fat When Eaten With Fructose Versus Glucose

Effect of Dietary Fat When Eaten With Fructose vs. Glucose on Insulin Resistance and Liver Fat

This study is designed to test the effects on liver fat of varying fat intake in the presence of fructose or glucose. We hypothesize that higher dietary fat when eaten with fructose as compared to glucose will increase the amount of hepatic lipid as measured by magnetic resonance spectroscopy.

After 2 screening visits including an exercise test, DEXA and CT scan, qualifiers begin a 7 day diet with 20% fat, 65% carbohydrate (with 20% glucose) and 15 % protein. Participants consume 2 meals per day at PBRC with lunch and weekend meals packed to go. Following a test day, participants are randomized to one of 3 diet assignments and then test again:

1)20% fat, 65% carbohydrate (with 20% glucose beverage), 15% protein 2)40% fat, 45% carbohydrate (with 20% glucose beverage), 15% protein 3)40% fat, 45% carbohydrate (with 20% fructose beverage), 15% protein On Day 7 and again 14 days later participants have labs, an oral Glucose tolerance test, hepatic and intramuscular lipid measures by MRS, vital signs and waist measurement.

Inclusion Criteria:

• BMI between 25 and 35 kg/m2 inclusive

• At least one of the following:

  1. Impaired fasting glucose between 100-125 mg/dl inclusive
  2. HDL below 40 mg/dl for men or below 50 mg/dl for females
  3. Triglycerides between 150 mg/dl and 400 mg/dl inclusive
  4. Blood pressure above or equal to 135 / 85 mm Hg

• Waist circumference >94cm (37 inches) for men or >80cm for women

• Mainly Healthy

Exclusion Criteria:

• Unable or unlikely to eat study foods and only foods provided by PRBC
• Taking routine medications except birth control pills
• Smoke, Abuse drugs,or Alcohol
• Pregnant or breastfeeding, irregular menstrual cycles, Post-menopausal,or PCOS
• Diabetes, heart, lung, liver, blood, or Kidney disease