An increase in dietary protein intake has been shown to blunt the increase in intrahepatic fat induced by high fat feeding in healthy individuals. The purpose of this study is to determine if a protein supplementation decreases intrahepatic fat in obese patients with non-alcoholic fatty liver disease.

12 obese patients will be be treated with a dietary whey protein supplementation over 4 weeks. Their intrahepatic fat content, glucose tolerance, and body weight will be evaluated before and after 4 weeks of supplementation.

Inclusion Criteria:

• BMI higher than 35 kg/m2
• age 18-50 years
• sex male or female
• ASAT/ALAT > 1.8

Exclusion Criteria:

• treatment with hypolemic or antidiabetic agents
• blood glucose > 7 mmol/l
• alcohol intake > 20g/day
• creatinin > 120 umol/l)
• contra-indications to Magnetic resonnance imaging