bioelectric impedance analysis (BIA) /-ilek″trik/ , a method of measuring the fat composition of the body, compared to other tissues, by its resistance to electricity. Fat tissue does not conduct electricity. Muscle and bone are poor conductors. The method is reported to be 95% accurate, depending on body water content, which may fluctuate with exercise, diet, sweating, and use of alcohol or drugs. See also total body electric conductivity.