Both, Diego Rodrigo; Matheus, Silvana CorrÃªa; Behenck, Mauri Schwanck
Introduction: The bioelectrical impedance (BI) is a fast, non-invasive and relatively inexpensive technique that can be applied in field situations or clinics. Its cost is ever lower, thus making equipment easy to purchase, but the accuracy of some equipment is still questionable due to the provision of information relating only to fat relative and/or absolute, failing to report values of resistance and/or reactance.
Objective: Evaluate the validity of the estimate of the percentage of body fat (%BF) obtained through BI analyzers tetrapolar and bipolar (hand to hand and foot to foot) using the hydrostatic weighing (HW) with a reference technique.
Methods: The %BF was measured in 102 men (18 – 30 years), with three equipment BI: Maltron BF-906 (tetrapolar); Omron 306BL (bipolar hand to hand) and Plena Ice (foot to foot) and HW. The accuracy was verified by paired t-test, correlation, standard error of estimate, constant error, total error and residue analysis.
Results: The BI hand to hand underestimated and BI foot to foot overestimated significantly (p<0.05) values of %BF. Already tetrapolar BI showed no significant difference, and showed the highest correlation value, lower constant error and total error and the highest percentage of agreement with the HW.
Conclusion: The equipment used in this study bipolar BI showed no accuracy to estimate relative body fat. Only IB tetrapolar brand Maltron BF-906 showed validity in determining %BF in the sample.