Submitted to: American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/1996
Publication Date: N/A
Interpretive Summary: Biomedical researchers have had an interest in the application of electricity to medicine and biology since the 18th century. Only within the past 50 years, however, have researchers attempted to use the body's capacity to conduct an applied, low level, radiofrequency current to index the amount and distribution of fluid in the body of healthy and ill people. This method is termed bioelectrical impedance analysis. One limitation to the general application of this approach has been the availability of acceptable models that permit the translation of electrical measurements to understandable volumes of fluid in the body. Three general models currently are available. One model, which relies on the assumption that the body resembles a wire conductor, has more error than the other proposed models. The two more recent models have not yet been tested sufficiently to determine their validity. The appeal of the bioelectrical impedance method is the ease of operation for the patient and test administrator, safeness and low cost relative to standard, reference methods. Preliminary evidence suggests that the bioelectrical impedance method may become a useful technique for assessing body composition in research and clinical medicine. This information will be useful for researchers and clinical practitioners.
Technical Abstract: Although the use of the bioelectrical impedance method for the indirect assessment of human body composition is growing, awareness of the theoretical and practical bases of the method is limited. This paper discusses the relationships between impedance variables and biological parameters, describes the biophysical models for the translation of impedance variables into in vivo body composition parameters, and summarizes the influences of physical and biological factors that affect the validity of the bioelectrical impedance method. It is clear that the practical advantages of the bioelectrical impedance method necessitate concerted research efforts to establish the most appropriate applications of the method in research and clinical medicine.