Bioelectrical impedance analysis for the estimation of body composition in rats.

Bioelectrical impedance analysis (BIA) was used to assess body composition in rats fed on either standard laboratory diet or on high-fat diet designed to induce obesity. Bioelectrical impedance analysis predictions of total body water and thus fat-free mass (FFM) for the group mean values were generally within 5% of the measured values by tritiated water (3H2O) dilution. The limits of agreement for the procedure were, however, large, approximately +/- 25%, limiting the applicability of the technique for measurement of body composition in individual animals.