Determination of body fat percentage by bioelectrical impedance analysis and dual-energy X-ray absorptiometry

Obesity is a risk factor for many chronic diseases. Several research methods are used to determine the amount of body fat, including the «gold standard» dual-energy X-ray absorptiometry (DXA). The bioelectrical impedance analysis (BIA) method is an alternative for assessing body composition that does not require special conditions for placement and examination, but the accuracy of its results depends on the hydration of the body.Objective. To compare the results of determining the percentage of body fat using multi-frequency (MF) BIA and DXA.Material and methods. The study included 20 volunteers (11 women and 9 men) aged 26 to 70 years without serious metabolic, cardiovascular or endocrine diseases. Two repeated measurements were performed using the MF-BIA method on the MS FIT device and the DXA method on the Lunar Prodigy Advance device.Results. There were no significant differences in the average percentage of body fat in repeated measurements by MF-BIA and DXA methods, and the intra-group correlation coefficients (r2 ) were 0.999 and 0.997, respectively. A high and significant correlation in percentage of body fat was found between the MF-BIA and DXA (r = 0.973, p < 0.001). The average difference between the results of these two methods was 0.1243%. Differences in percentage of body fat that exceeded two or more standard deviations were detected less than in 5% cases, so the data on body fat content estimated using DXA and BIA are consistent and can be considered almost equal.Conclusion. Our study has shown that the MS FIT body composition device using the MF-BIA method can be an alternative to DXA for assessing the percentage of body fat without introducing additional formulas to recalculate the data obtained.