Which index best correlates with body fat mass: BAI, BMI, waist or WHR?

OBJECTIVES: The body mass index (BMI) has been the most commonly applied clinical measure to characterise body composition in individuals. However, the BMI has been criticised as being an inaccurate measure of body fatness. Recently, a new index reflecting body composition, the Body Adiposity Index (BAI) was proposed. The BAI was calculated using the equation BAI=((hip circumference)/ ((height)1.5) - 18).

AIM: The aim of this study was to compare estimates of body fat content, i.e., body adiposity index (BAI), BMI, waist-hip ratio (WHR) and waist and hip circumferences, with respect to their ability to predict the percentage of body fat (PBF).

RESULTS: To select an optimal surrogate for adiposity, we examined the correlation between body adiposity percentage as measured by BIA and several variables, including BAI, BMI and WHR. Correlations ranged from a high of 0.78 for BMI, 0.67 for BAI and 0.66 for waist circumference to a low value of 0.39 for the WHR index. The correlation between PBF and BAI (R=0.67, R2=0.45, p<0.001) and the correlation between PBF and BMI (R=0.78, R2=0.60, p<0.001) were of similar magnitude.

CONCLUSION: Based on our results and those of other studies, we can say that the BAI index is not a universally valid index that could be used in the place of the BMI index in a Caucasian population; indeed, it would not accurately reflect body fat mass and thus could lead to an increased risk of obesity. Further, WHR index is not a suitable for an estimation of body fat.

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