Twenty-two healthy overweight/obese males and females, aged between 45-70 years and BMI between 27-35 kg/m2 will participate in the whole study. To create a continuum in liver fat content, eight subjects with liver fat content lower than 5% and 14 subjects with liver fat content higher than 5% (NAFL) will be included. At least seven volunteers with NAFL will have severely elevated hepatic fat content (liver fat percentage ≥ 15%).