The body adiposity index (BAI) is a method of estimating the amount of
body fat
Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular e ...
in humans. The BAI is calculated without using body weight, unlike the
body mass index (BMI). Instead, it uses the size of the
hips
In vertebrate anatomy, hip (or "coxa"Latin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) in medical terminology) refers to either an anatomical region or a joint.
The hip region ...
compared to the person's height.
Based on population studies, the BAI is approximately equal to the percentage of body fat for adult men and women of differing ethnicities.
Formula
The BAI is calculated as:
Hip circumference (
Pearson correlation coefficient
In statistics, the Pearson correlation coefficient (PCC, pronounced ) ― also known as Pearson's ''r'', the Pearson product-moment correlation coefficient (PPMCC), the bivariate correlation, or colloquially simply as the correlation coefficient ...
, R = 0.602) and height (R = −0.524) are strongly
correlated
In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statistic ...
with percentage of body fat. Comparing BAI with "
gold standard
A gold standard is a monetary system in which the standard economic unit of account is based on a fixed quantity of gold. The gold standard was the basis for the international monetary system from the 1870s to the early 1920s, and from the l ...
"
dual-energy X-ray absorptiometry
Dual-energy X-ray absorptiometry (DXA, or DEXA) is a means of measuring bone mineral density (BMD) using spectral imaging. Two X-ray beams, with different energy levels, are aimed at the patient's bones. When soft tissue absorption is subtracted ...
(DXA) results, the correlation between DXA-derived percentage of adiposity and the BAI in a target population was R = 0.85, with a
concordance
Concordance may refer to:
* Agreement (linguistics), a form of cross-reference between different parts of a sentence or phrase
* Bible concordance, an alphabetical listing of terms in the Bible
* Concordant coastline, in geology, where beds, or la ...
of C_b = 0.95.
Uses
The BAI could be a good tool to measure adiposity due, at least in part, to the advantages over other more complex mechanical or electrical systems. Probably, the most important advantage of BAI over BMI is that weight is not needed. However, in general it seems that the BAI does not overcome the limitations of BMI.
Stated advantages of the BAI are that it approximates body fat percentage, while the widely used BMI is known to be of limited accuracy, and is different for males and females with similar percentage body adiposity; and that it does not involve weighing, so can be used in remote locations with limited access to scales. A detailed study published in 2012 concluded that estimates of body fat percentage based on BAI were not more accurate than those based on BMI, waist circumference, or hip circumference.
Adiposity indexes that include the waist circumference (for example
waist-to-height ratio WHtR) may be better than BAI and BMI in evaluating metabolic and cardiovascular risk in both clinical practice and research.
References
{{Reflist
External links
New obesity index proposed, but further work needed (theheart.org)
* ttp://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0035281 Body Adiposity Index Utilization in a Spanish Mediterranean Population: Comparison with the Body Mass Index
Classification of obesity
Obesity
Body shape
Human body weight