What differences are there between race and ethnic groups regarding body fat, body mass index?
This article is a tour-de-force summary of many of the reasons why different racial group/ethnicities/nationalities should have different BMI overweight criteria. Below are some excerpts that I found useful, when I searched for race-specific Body Mass Index adjustments for Black Americans and Asians.
- "It is now generally accepted that African-Americans have a higher bone mineral density and bone mineral content than whites, and that their muscle mass is higher1."
- "It is now generally believed that African-Americans have less visceral fat than matched (for age, BMI, circumference ratios) Caucasian Americans." "the lower amount of visceral adipose tissue among American Blacks (matched for BMI) could turn out to be an artefact, as their total body-fat levels could be lower."
- "The bioelectrical impedence of the body is, to a large extent, determined by the impedance of the limbs2… and there are clear differences in limb length between ethnic groups."
- "Subjects with relatively long legs will have lower BMIs… (for example) the ‘longleggedness’ of the Australian aboriginals contributes to 2 kg/m2 to their low BMI3."
- "Hong Kong Chinese have high BF% (body fat percentage) values at low BMIs and proposed BMI cut-off points for overweight and obesity as low as 23 and 26 kg/m2, respectively.4"
- "In Indonesia, the BMI cut-off for obesity has been set at 27 kg/m2."
Update in 2015. It has come to light that perhaps the high body fat measurements made in Asian peoples, was not scientifically valid for technical reasons, perhaps due to Asians having shorter legs, which affected the impedance results. That’s me guessing what the problem was, but not certain. But the whole idea that Asians have more fat at the same BMI, is probably false.
- Wagner DR, Heyward VH. Measures of body composition in blacks and whites: a comparative review. Am J Clin Nutr 2000; 71:1392-1402.
- Fuller NJ, Elia M. Potential use of bioelectrical impedance of the ‘whole body’ and of body segments for the assessment of body composition: comparison with densitometry and anthropometry. Eur J Clin Nutr. 1989; 43:779-791.
- Norgan NG. Interpretation of low body mass indices: Australian Aborigines. Am J Physical Anthropol 1994; 94;229-237.
- Ko GTC, Tang J, Chan JCN, et al. Lower BMI cut-off value to define obesity in Hong Kong Chinese: an analysis based on body fat assessment by bioelectrical impedance. Br J Nutr. 2001; 85:239-242.