Which Is Better: BMI or Body Adiposity Index?

In related news, another measure is gaining acceptance when it comes to accurately detecting body fat.

Unlike BMI, which uses height and weight to estimate body fat, the body adiposity index (BAI) does not take weight into account. Instead, it uses the following calculation: hip circumference (in centimeters) / height (in meters) (1.5) – 18. In a study published in the journal Obesity (2012; 20 [4], 900–903), scientists examined whether BAI is really a better body fat indicator than BMI.

They compared DXA body fat percentage measures against both BMI and BAI data gathered from 623 adults. “In the sample as a whole, the agreement between BAI and body fat percentage was far better than between BMI and body fat percentage, but was nonetheless relatively poor,” the authors stated. They found that major discrepancies occurred between DXA and BAI among individuals with lower levels of body fat. BAI also tended to overestimate fat percentage in males and to underestimate fat percentage in females.

“Results of the present study show that BAI provides a better indicator of adiposity in European-American adults than does BMI, but does not provide valid estimates of fat percentage, particularly at lower levels of body fatness,” concluded the authors.