Where are you on the global fat scale?

http://www.bbc.co.uk/news/health-18770328

by mikecane • 14 years ago

22 38 14 years ago

bbc.co.uk

tfb• 14 years ago

I'm really not a fan of BMI being the determining factor in obesity. At 27 BMI, I'm apparently 3 BMI away from being considered obese. As a naturally large, fairly muscular 24 year old german/irish man, I'm 6 foot 1 and weigh 205 lbs, but you can see my abs and I'm in relatively good physical condition. Is my definition of obese wrong? I always thought obese meant someone with at least a few dozen lbs of excess fat.

streptomycin7• 14 years ago

Invent a way of easily measuring body fat percentage, and we can do away with BMI. Until then, muscular people can simply ignore these things. BMI works well enough for the rest of the population (the vast majority of the world). If anything, normal people have the opposite problem you do. BMI tends to underestimate obesity in the general population. http://www.cnn.com/2012/04/03/health/obesity-rates-maybe-wor...

evilmushroom2• 14 years ago

There are techniques for doing this.

I weight lift... a lot. So BMI is utterly useless for me (as you said)

dredmorbius8• 14 years ago

A simple waist circumference measurement is more accurate than BMI at making individual assessments of obesity (> 40" ~ 100cm is bad).

A set of 3-4 tape measurements (height, neck, abdomen for men; height, neck, waist, hips for women) will give a reasonable estimate of body fat. Equipment cost, about $5. http://www.linear-software.com/online.html

Your observation of the weakness of BMI is that it tends to misreport true body fat percentage both ways. I'd hardly call that an advantage of BMI.

Note that since official US government policy defines obesity in terms of BMI, technically, BMI doesn't misreport obesity. What it does is fail to correspond to true body fat percentage in any meaningful way.

graeme3• 14 years ago

This is true, but it's impact is overestimate. I used to hover near the 25 level for my BMI. I was muscular, so I thought it was silly.

But I've not lost 6 pounds while gaining strength. I can see my abs. Turns out I was 12 pounds over my high school weight.

I'd now need ~8 pounds of extra muscle to become "overweight". That's a lot.

I think it's hard to go over BMI based on muscle alone. You may have less of a problem is you're BMI 25 and muscular, but you still probably could stand to lose some fat.

krschultz• 14 years ago

Well, I have a scale at home that does Body Fat %, and it is reasonably accurate. (It is consistent day to day, compared to a doctor's office one its off by maybe 1%).

I believe it was $50. There are several on Amazon for that price and lower. If a regular scale is $20, and one that measures body fat is $40, then I don't think it's a big deal. I personally watch the body fat % now rather than weight.

scott_s• 14 years ago

This uses the body-mass index, which does not measure fat. It's just a ratio of height to weight, which does not take body composition into account.

gaius3• 14 years ago

It is really irresponsible of the BBC to be promoting BMI as a measure of health.

I'm a Marathon runner who is apparently fatter than 99% of the world...

evilmushroom2• 14 years ago

This is flawed, very flawed. I weight lift now and workout 6 days a week... in college I was a skinny 5'11" and 130. I'm not 5'11" and 186.

This is going to tell me I'm fat.

graeme3• 14 years ago

Can you see your abs? Serious question.

I hovered around 25 BMI, was muscular, thought it was silly. Everyone considered me "lean". But, no abs.

Now I can see mine, am very strong, and have a 23 BMI.

It's possible BMI effectiveness changes with height though, which would make it even worse. I'm 5'6".

victork22• 14 years ago

Before complaining about "wah wah that's BMI, BMI sucks" please think twice. Everybody knows it's BMI, BMI is a rough measurement of your ratio height to weight.

http://en.wikipedia.org/wiki/Body_mass_index#Limitations_and...

"The medical establishment has acknowledged major shortcomings of BMI.[...] found that BMI-defined obesity was present in 21% of men and 31% of women. Using body fat percentages (BF%), however, BF%-defined obesity was found in 50% of men and 62% of women."

Take it as a statistical game and stop getting self conscious about it.

Note also: If you are very muscular with a crazy BMI despite no fat it's not healthy either.

gaius3• 14 years ago

No "everyone" doesn't know that BMI is discredited, the BBC should have put a huge disclaimer on it saying "these numbers are nothing to do with how healthy you are, in fact they are completely meaningless".

victork22• 14 years ago

I like how I got downvoted. Please read everything that is on the website:

The BBC say it's an estimate, with a link on estimate leading to its definition and a disclaimer about BMI.

They never say that you are fatter or slimmer than the rest of the population but they talk about your BMI and your BMI only, just a quote:

"You have a lower BMI than 88% of males aged 15-29 in your country"

"You have a lower BMI than 54% of males aged 15-29 in the world"

I really don't see anything about weight or any scheme to make you think you're fat if you have a high BMI from the BBC like some imply in the comments. It's very funny how hyper defensive everybody gets around the BMI thing, especially the ones who don't have the "right" BMI.

vonmoltke• 14 years ago

Note also: If you are very muscular with a crazy BMI despite no fat it's not healthy either.

I hear this claim parroted quite a bit. I haven't seen any evidence of this in medical literature, though, except in cases of really big guys like NFL lineman. Do you have any references for the claim?

dredmorbius8• 14 years ago

BMI is an utterly bogus means of determining individual fitness assessments, and there's some reason to believe it's not very useful for population measures of fitness.

- Top 10 Reasons Why The BMI Is Bogus : http://www.npr.org/templates/story/story.php?storyId=1062684...

- Beyond BMI, Why doctors won't stop using an outdated measure for obesity : http://www.slate.com/id/2223095/

- Do You Believe in Fairies, Unicorns, or the BMI? : http://www.maa.org/devlin/devlin_05_09.html

dxbydt• 14 years ago

Dude, thanks for linking to Dr. Keith Devlin's column. Probably the only thing I read religiously in the MAA.

BMI is just one of several mistakes attributed to the great mathematician Quetelet. You can credibly implicate Quetelet for a variety of modern day statistical crimes such as profiling ( attempting to figure out if a person is a criminal based on statistical analysis of race/sex/height/etc...),"normal" age of marriage, statistical rates of divorce in different countries and their implications on fidelity, and such other sociological nonsense.

Dr. Devlin labels these things "junk math, numerological nonsense". But you can take a more charitable view - given that Quetelet practically invented both statistics & sociology ( which he called "physics of society" ), he came up with a number of formulae that seemed true at that time ( mid 1800s ). On hindsight much of this stuff is just silly mathematical manipulation ( Instead of dividing weight by square of height & multiplying by the constant 703, you can square the weight & divide by the cube root of height and put in some other constant...) If you are interested in the kind of statistics practiced in Quetelet's timeframe, here's some wacky references.

http://en.wikisource.org/wiki/Popular_Science_Monthly/Volume...

http://statistiks.net/wp-content/plugins/downloads-manager/u...

btw, much of what we do today in quant finance is suspiciously similar to what Quetelet suggests :) We build statistical "factor models" that credibly relate earnings of a company in california to the price of chicken in China :) We take a rigged number called the LIBOR & price interest rate derivatives on the spead between this rigged fixed rate & the floating rate. Then the public loses money & we scream - hey who the fuck rigged the LIBOR in the first place ?:) Talk about bootstrapping... honestly, we are no different from Dr. Quetelet. Might as well base Google's quarterly earnings on Page's BMI.

dredmorbius8• 14 years ago

That's Dr. Dude to you.

Quetelet's work was reasonably appropriate for his time. One source I recall (cannot find it now) stated that he was looking for a rapid paper-and-pencil method for estimating aggregate troop strength. As a basic, good-enough first approximation, BMI works reasonably well. The problem is that it's now been grossly misapplied.

Quants (and economists) spend, I suspect, a lot of time chasing what turn out to be transitory relationships between various measurements. The relationships may very well be statistically valid, when first measured, but either changing real-world conditions, or, more likely in the financial world, adoption of the relationships by others seeking profits, rapidly erodes their validity.

Thanks for the links, I've got some reading for later :)

An enterprise I had some association with in the past spent some years and considerable capital trying to establish a strongly predictive relationship between a physical property and a health measurement. It turns out that there was a relationship, but not one which could be reliably used to determine an accurate quantification of the health measurement. This didn't keep them from torturing the data extensively.

And Page's health is in the news today: http://www.washingtonpost.com/google-ceo-larry-pages-health-...

mathewsanders• 14 years ago

Is anyone else having problems with this? I've tried loading in Chrome, Safari and Firefox and each time a js is not loading and my BMI as '0'

Tooluka• 14 years ago

You probably input Height in centimeters. Try inputting 1.xx (or 2.xx).

excuse-me• 14 years ago

Damn averages.

By moving to a city with a lot of S.E. Asian people I'm suddenly above average BMI - I need to move back to Texas.

On the other hand, all those little old Japanese women mean that the average life expectancy here is among the highest in the world - so I should live to a 100 like them

cryptide• 14 years ago

>> You're most like someone from Mongolia

Reply

jere• 14 years ago

I hate BMI too (moderately lean according to body fat, but nearly obese according to BMI).

But whether you're muscular or fat, this scale is a pretty good reminder of how well nourished we are compared to everyone else.

Reply

mithras• 14 years ago

Speak for yourself:

"You're most like someone from DR Congo"

Reply

graeme3• 14 years ago

They messed up median and average. I'm above the global "average", but if everyone were like me, the world would lose weight!

They clearly mean I'm heavier than most people, but lighter than the average BMI. Very large people skew the average upwards.

Edit: I am wrong. See the comment below. I thought average referred to arithmetic mean.

Reply

dredmorbius8• 14 years ago

Median is an average measure. As are arithmetic mean and mode.

You're messing up "average" and "mean" :)

Reply

thekungfuman• 14 years ago

I was really interested to see this data until I saw that they use the BMI; possibly the dumbest and most loudly touted measure of health. According to these numbers I am overweight, heading towards obese, and I don't think any doctor on Earth would say I was overweight if they looked at me.

Reply

Where are you on the global fat scale?

Related Stories