Body composition determination by bioimpedance: an update.
OBJECTIVE
To review various methods for measuring body composition by bioimpedance and their limitations, as well as available impedance meters, including body fat analyzers for home use.


RESULTS
Bioimpedance spectroscopy, which requires multifrequency impedance meters, is preferable for fluid volume measurements, especially extracellular fluid, whereas bioimpedance analysis at 50 kHz is more widely used for measuring fat-free mass. A method for using bioimpedance spectroscopy equations with 50 kHz impedance meters has been recently proposed and successfully tested. Low cost foot-to-foot impedance meters (body fat analyzers) with plantar electrodes on a body scale, that are easy and fast to use, have been compared with medical impedance meters and with dual X-ray absorptiometry measurements and found reasonably accurate, except for individuals with very low or high BMI.


CONCLUSIONS
Body composition by bioimpedance is gaining acceptance in nutrition, hemodialysis, gerontology and sports medicine. Body fat analyzers that have been validated by comparison with dual x-ray absorptiometry could be useful to general practitioners, nutritionists and cardiologists.
Jaffrin
Michel Y
MY
Department of Biological Engineering, UMR CNRS 6600, University of Technology of Compiegne, Compiegne, France. michel.jaffrin@utc.fr
D000273:Adipose Tissue / Q000378:metabolism*; D001823:Body Composition / Q000502:physiology*; D001825:Body Fluid Compartments / Q000502:physiology*; D015992:Body Mass Index; D001834:Body Water / Q000378:metabolism; D017097:Electric Impedance; D045604:Extracellular Fluid / Q000378:metabolism; D006801:Humans; D018482:Muscle, Skeletal / Q000378:metabolism*; D010992:Plethysmography, Impedance; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity