Validity of body adiposity index in predicting body fat in a sample of Brazilian women

Abstract

Objective: This study aimed to verify the validity of BAI in predicting %BF in a sample of Brazilian women

Design and methods: A total of 102 women (average age 60.3 ± 9.8) were assessed. To determine percentage body fat (% BF), dual-energy X-ray absorptiometry (DXA) was used as the "gold standard." To evaluate the association between body adiposity index (BAI) and % BF assessed by DXA, we used Pearson's correlation coefficient. Paired sample t-test was used to test differences in mean % BF between BAI and DXA. To evaluate the concordance between % BF measured by DXA and estimated by BAI, we used the Lin's concordance correlation coefficient and the agreement analysis of Bland-Altman.

Results: The correlation between % BF obtained by DXA and that estimated by BAI was r = 0.65, P < 0.001. Paired t-test showed significant mean difference between methods (P < 0.0001). Lin's concordance correlation coefficient was C_b = 0.73, which is classified as poor, while the Bland-Altman plots showed BAI underestimating % BF in relation to the used criterion measure in a large portion of the sample.

Conclusions: Results of the present study show that BAI presented low agreement with % BF measured by DXA, which is not recommended for % BF prediction in this studied sample.

Keywords: body adiposity index; body fat; women.