[Possibilities of calculating the fat-free body mass and its reaction to a carbohydrate-poor, fat-rich diet].

9 healthy medical students got an isocaloric fat-rich carbohydrate-reduced diet during 14 days. Body-weight and lean body mass were registrated. We calculated lean body mass from measurement of skinfold thickness, total body potassium and total body water. Body-weight was reduced highly significantly by 3.4 kg on an average. Body potassium and body water remained unchanged. It can be concluded from these results that weight loss was caused by an exclusive reduction of the fat mass.