Long-term Investigation of Resveratrol on Fat Metabolism in Obese Men With Nonalcoholic Fatty Liver Disease

The purpose of this study is to investigate potential metabolic effects of resveratrol in obese healthy men with non-alcoholic fatty liver disease. The investigators hypothesize that resveratrol will: * decrease hepatic very-low-density-lipoprotein-triglyceride (VLDL-TG) secretion * decrease liver fat content * increase insulin sensitivity The investigators will look at changes in: * lipid turnover (VLDL-TG kinetics, palmitate kinetics, indirect calorimetry) * liver fat content (MR liver spectroscopy) * insulin sensitivity (glucose kinetics during hyperinsulinaemic euglycaemic clamp) * body composition (DXA and MRI) * lipase activity and fat cell size (fat biopsy from abdominal and femoral adipose tissue)