Effects of low-fat vs high-fat diet on lipid accumulation in liver and skeletal muscle in overweight men

INTERVENTION: Both groups, the control group and the experimental group, will start with 3 weeks on a low‐fat diet which will deliver 15 Energy% of energy as protein, 65 En% as CHO and 20 En% as fat. After these 3weeks the experimental group will switch to a high‐fat diet (15 En% protein, 30 En% CHO and 55% En% fat). wheras the control group stays on the low‐fat diet. CONDITION: ; Diabetes Mellitus type 2 (DM type II), Insulin resistance, Non‐Alcoholic Fatty Liver Disease (NAFLD) ; ; PRIMARY OUTCOME: Main study parameter is the difference in lipid accumulation and insulin sensitivity after a switch from a low‐fat diet to a high‐fat diet compared to the control group, which stays on a low‐fat diet. SECONDARY OUTCOME: As secondary endpoints differences the time‐course of lipid accumulation and the relationship between the tissue parameter lipid ccumulation and the functional outcome parameter insulin resistance are considered. INCLUSION CRITERIA: 1. Male sex; 2. Age 40‐65 years; 3. BMI 25‐35 kg/m2; 4. Sedentary; 5. Stable dietary habits; 6. Healthy.