THE COMPOSITION OF WEIGHT-LOSS IN DIETING OBESE FEMALES BY ELECTRICALMETHODS

The fat and fat-free components of the weight loss of a group of obese females undergoing a clinically monitored dieting regime have been es timated by two noninvasive electrical techniques, bioelectrical impeda nce analysis (BIA) and tissue resonance impedance monitoring (TRIM). T hese two procedures are described and results presented for a group of volunteers representing a wide range of body mass index. During the 1 1 weeks of the study the members of the group were on a 405 kcal liqui d ketogenic diet. Within experimental error, the estimates of changes in body composition by the two methods agree with each other and also with estimates determined by tritiated water dilution and neutron acti vation measurements on the same group of subjects. The average loss in body mass was 16.2 kg, representing approximately 18% of the average initial body mass. The loss comprised about 20% fat-free tissue and 80 % fat tissue. The safety, convenience and non-invasive nature of the e lectrical techniques makes them useful additional procedures to be dep loyed in the routine monitoring of body composition.