Effects of an Amino-acid Supplement on Hepatic Lipid Metabolism

10 healthy male volunteers will be studied after * a 6 day weight maintenance, balanced diet * a 6 days weight maintenance, balanced diet supplemented with 3 grams fructose/kg body weight/day * a 6 days weight maintenance, balanced diet supplemented with 3 grams fructose/kg body weight/day and 20g amino-acids per day At the end of each 6 days period, the following measurements will be obtained * intrahepatic lipids (1H-MRS) * metabolic effects of fructose ingestion (measurement of substrate oxidation, gluconeogenesis from fructose, palmitate synthesis from fructose, plasma VLDL-kinetics) This is a randomized, double blinded study