Validity of field measurements for body composition

Abstract

Purpose: This study was designed to test the validity of four field measurements for body composition against the standard laboratory measurement. Methods: Six participants were recruited from KSS 860 Research Methods in the Profession (2 male, 4 female). Participants were measured for % body fat by five methods: dual-energy x-ray absorptiometry (DXA), skin-fold calipers (SKF), anthropometric measurements (ANT), and Tanita bioelectrical impedence scale (athlete mode =BIA; non-athlete mode = BINA). Field measurements were recorded in duplicate staggered by 7 days. All field measurements were recorded by an experienced technician. DXA values were recorded within the same week as the first set of field measurements. Mean values for each field test were calculated and used to asses validity compared to DXA. Validity of each field test was assessed using bi-variate Pearson’s correlation coefficients. Significance was set at p<0.05. Results: This study found that the anthropometric equations for measuring % body fat yielded valid results when compared to DXA (r = 0.963, p<0.01). In contrast, SKF, BIA, and BINA did not yield valid results for measuring % body fat when compared to DXA (r = 0.798, p = 0.057; r = 0.712, p = 0.177; r = 0.702, p = 0.187). Conclusion: Anthropometric measurements have been shown to yield valid results when used to quantify percent body fat in field settings. The use of skinfold calipers, and the Tanita bioelectrical impedance scale should be avoided as the results are not valid when compared to the laboratory standard.