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by suprathreshold 3610 days ago
In reading the paper, I appreciate the statistical efforts to adjust for age differences between the groups to make their claim, but at least optically it doesn't help that the average age of each cohort was already 10 years different. Lean group M = 48 yrs SD = 16; Overweight M = 57 years SD = 17; Obese M = 61 years SD = 16. The latter two groups were combined for analysis.

Is it still contentious to use the BMI to define these groups? http://www.npr.org/templates/story/story.php?storyId=1062684...
1 comments
bargl 3610 days ago
Doesn't BMI that uses electrical current to check for fat percentage in body negate the conetentiousness of BMI? I ask because I thought that was the case but now I'm not so sure.
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jaegerpicker 3610 days ago
There is no BMI measurement that use's electrical current. That's a body fat index which is very different and much more precise. BMI is a very poor and ultimately very hard to justify formula that only takes into account weight/height sorted by gender. Things like muscle index and body frame are completely ignored and often lead to very poor BMI's for people who shouldn't have them.
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suprathreshold 3610 days ago
Maybe bargl means Bioelectric Impedance Analysis? A cursory internet search also indicates BIA is suspect as a one-time measure.
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bargl 3610 days ago
OK so I have this and I thought that the BMI it computed was based on tracking the fat to everything else based on BIA. But I may be way off here.

https://www.fitbit.com/aria

I see that Fitbit tracks this as BodyFat % not BMI. Not sure if that's accurate.

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raffy 3610 days ago
BIA is pretty bad. Here are ~1300 Fitbit Aria measurements matched against 7 DXA scans. The Fitbit bodyfat data (teal) is just random noise and can barely detect considerable changes in body composition.

http://i.imgur.com/J4Ls2bQ.png

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noir_lord 3610 days ago
I stopped paying attention to be BMI, I'm 6ft, 190lbs and have a 32" waist and it has me right on the edge of been overweight.

I think given that many people don't realise how inaccurate it is I might even class it as harmful.

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SamReidHughes 3609 days ago
You are on the edge of overweight, and you don't realize it because of all the fat people around you.
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