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Author Topic: Does body mass index (BMI) take race into account ?  (Read 6135 times)

JP

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The other day I saw a site (from a hospital), with details on their programs for maintaining healthy weight.  They had categories for "caucasian" and "asian" with two different BMI charts.  So my question is: are there significant differences in what is considered a healthy BMI for people of different races/ethnicities? 
« Last Edit: 15/02/2010 17:25:49 by chris »

Jolly- Joliver

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Does body mass index (BMI) take race into account ?
« Reply #1 on: 10/05/2011 21:19:03 »
The other day I saw a site (from a hospital), with details on their programs for maintaining healthy weight.  They had categories for "caucasian" and "asian" with two different BMI charts.  So my question is: are there significant differences in what is considered a healthy BMI for people of different races/ethnicities? 

Surely you have answered you own question if they had two different tests for Asian and western people the answer must be yes, however it is a generalised chart all people are different ultimately.

JP

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Does body mass index (BMI) take race into account ?
« Reply #2 on: 11/05/2011 08:36:28 »
Wow, this post has come back from the dead!

I should probably have clarified that my question came up after moving from the US to Singapore.  I saw this in a Singaporean hospital.  In the US, I have always been told there is one BMI chart for everyone.  My question should have been is there any real evidence that ethnicity plays a role in what a healthy BMI range is? 

I've since heard that BMI is a fairly poor judge of healthy weight, since many factors play into it, so maybe any claims about BMI should be taken with a grain of salt.

stame

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Does body mass index (BMI) take race into account ?
« Reply #3 on: 18/05/2011 07:50:33 »
Yes! it does. Telling this from my personal experience while going asia to UK countries O8)

CliffordK

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Does body mass index (BMI) take race into account ?
« Reply #4 on: 18/05/2011 19:43:59 »
Interesting.

There are several notes about Caucasian/Asian BMI on the WWW.

All Asian populations studied had a higher BF% at a lower BMI compared to Caucasians. Generally, for the same BMI their BF% was 3-5% points higher compared to Caucasians. For the same BF% their BMI was 3-4 units lower compared to Caucasians. The high BF% at low BMI can be partly explained by differences in body build, i.e. differences in trunk-to-leg-length ratio and differences in slenderness. Differences in muscularity may also contribute to the different BF%/BMI relationship. Hence, the relationship between BF% and BMI is ethnic-specific. For comparisons of obesity prevalence between ethnic groups, universal BMI cut-off points are not appropriate.

For Singapore Asians, the study suggests using a BMI of 27.0 as the cutoff for Obesity ( instead of 30 ), and using a Body Mass Index of 21.0 as the cutoff for Overweight ( instead of 25 ), because these values match the same body fat percentages as caucasians.

These values also match the values used in Indonesia.

Singapore's 3 main ethnic groups: Chinese, Malays and Indians have slightly different body fat, body composition differences. The Obesity threshold for Singapore Indians would therefore be 26.

JP

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Does body mass index (BMI) take race into account ?
« Reply #5 on: 19/05/2011 04:00:54 »
Thanks, those are interesting links.  So I guess the point is that BMI is a poor system of measuring health, and that fat percentage is probably better.  Different ethnic groups vary in the percentage of body mass made up of fat.

CliffordK

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Does body mass index (BMI) take race into account ?
« Reply #6 on: 19/05/2011 05:17:00 »
It probably also takes into account "frame size" and average muscle mass.

So, if you are calculating BMI based on height and weight, then if a race typically has lower muscle mass and a smaller frame, then if they have the same overall weight as another race with larger frames/muscle mass, then they will appear fatter.

Bored chemist

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Does body mass index (BMI) take race into account ?
« Reply #7 on: 19/05/2011 18:19:28 »
BMI is a number, it's calculated from height and weight (or mass if the physicists want to get fussy).
It is not, of course, dependent on race or even species. You can calculate it for a horse if you have nothing better to do. ( I suspect that a horse that was starving to death would end up with a BMI that indicated that it was grossly obese if you compared it to human "normal" values.)

What you do with that number is another matter. If you want to use it as some sort of proxy measure for health then you need to take a lot more things into account (like race, muscle mass, sex, age etc) or you can just accept that it isn't as good a measure as it might be.

 

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