Changes in fat-free mass during weight loss measured by bioelectrical impedance and by densitometry.
A group of 13 apparently healthy, premenopausal obese women (134-196% ideal weight) volunteered in a weight reduction study for 8 wk on a 4200 kJ (1000 kcal) diet. Before and after the weight reduction period body composition was measured by densitometry and by the bioelectrical impedance method. Changes in fat mass and fat-free mass were calculated. Mean weight loss was 10.0 +/- 2.8 kg and loss of fat-free mass was measured to be 2.3 +/- 1.7 kg (23%) by densitometry and 0.6 +/- 1.9 kg (6%) by impedance measurements. The underestimation of the change in fat-free mass measured by the impedance method could be due to losses of water bound to glycogen after the weight-reduction period. For this reason the impedance method may be not applicable in studies in which changes in glycogen stores can be expected.
Deurenberg
P
P
Department of Human Nutrition, Agricultural University, Wageningen, The Netherlands.
Weststrate
J A
JA
Hautvast
J G
JG
D000328:Adult; D001823:Body Composition; D001827:Body Height; D003720:Densitometry; D004038:Diet, Reducing; D004553:Electric Conductivity; D005260:Female; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D015431:Weight Loss
D006003:Glycogen