BMI is Bunk

[BRPORSCHE]

What a load of crap.

Have been working out 5 days a week for four months now. Weighed and measured my BMI before the start as 230 and 24% BMI respectively. I used this BMI calculator to give me an accurate reading of my BMI. I have broad shoulders so I can't just enter my height and weight.



Well according to the "chart" a 6 ft tall person weighing 230 pounds should have a BMI of 29.5% which is 5.5% more then I actually measured!

So today I went to measure myself today and am down to 210 and have a BMI of 20%. The chart still wants me to have a 28.5% BMI! Do Doctor's actually use this as a form of determining obesity?

Shaking my head....

[sjf911]

BMI is not reported as a %, body fat is. BMI is in kg/m^2.

[BRPORSCHE]

Whoops thank you for that! Atleast I was consistent with my error.

[red-beard]

That chart was developed from US Military data of entering soldiers for WWII, while the US was still in depression...

[jyl]

Spend $50, get a scale that measures your body fat. Omron HBF 400 or similar. More accurate, more relevant.

[Gogar]

If I was in the green on that chart people would think i was ill. I DID fit in the green on that chart, when I was 15.

[Tobra]

BMI is a worthless metric for most people, especially if they are at all athletic.

According to that chart, I am currently 20 pounds overweight, and when I was in the best shap of my life, it was 30. Of course when I weighed 195, I had a sub 5% body fat.

[Erakad]

Agree....BMI is bunk. It's time to move on from outdated, misleading metrics. I could go on for hours how the table is nonsense, but really, its just time to move to more meaningful measures. Literature now is very supportive of waist-height (ration less than 0.5), which doesn't penalize tall people.

[Geronimo '74]

Originally Posted by Tobra

According to that chart, I am currently 20 pounds overweight, and when I was in the best shap of my life, it was 30. Of course when I weighed 195, I had a sub 5% body fat.

Are you sure you are not mistaken?
That condition is only maintainable for a few hours at a time and is practically only done by pro bodybuilders. With this low level of body fat, the water content of your body is dangerously low(subcutaneous water levels are near 0), borderline life threatening even.
Even a BF percentage of 5-7 is only maintainable for a few days with careful dieting.

this is what sub five percent looks like.




Here a very interesting link on the subject.
http://www.traindaly.com/tag/obese/

[cbush]

It has nothing to do with how good a shape you are in. It also doesn't account for out of average body shapes and muscular builds. It is a good tool though for screening. If you have a high level of body fat according to the chart, then perhaps you should discuss it with your doctor, and get their advice- along with blood tests for cholesterol. I defer to Tobra on any medical advice though.
We are pretty good at rationalizing being "overweight" and in fact probably like the way we look. Doesn't mean it is good for us.
One more tidbit from the military--the US Air Force, at least until recently, used a 32 inch waist measurement as the basis for their fitness test. Anything over 32 inches was a deduction. How many of us would do well on that test? Not me, and I am in the green category-despite being 10 pounds over my ideal weight.

[1990C4S]

Why do you need a chart to see if you are overweight? Don't you have a mirror?

BMI is on the way out, it's yesterdays news.

[Tobra]

Yes Geronimo, I am certain that I am not mistaken, though I may have exaggerated slightly. It was 5 point something, less than half what my girlfriend at the time was.

A friend of mine was doing a study when he was going to OSU. I seem to recall he weighed me in and out of a tank of water, or measured how much water my body displaced, something like that. I was doing a lot of cycling and weight training at the time. Interesting thing, girl I was dating then was a track athlete that was a shade over 12%, at the beginning of her season. He checked her again at the end of the seaosn and it was closer to 10 and she had quit having her period.


I suppose it is not a precisely measured value. Matter of nutrition, activity and genetics.

[Geronimo '74]

Measuring by immersion is a good way to determine BF%. (but no measurement is 100% accurate)
I reckon you looked pretty impressive, 195lbs and 5.something BF
I'm 200lbs at 14.something, aiming for sub10% with dieting and running. (I still work out too)
Women generally need 12-13% BF to be healthy, so if your GF at the time was close to ten, I'm not surprised her body started to protest.

[jyl]

I was also 5-something % body fat in my late twenties, per a very detailed physical. Was not weighed in water, I guess they measured electrically, don't really remember.

[cbush]

There are numerous ways to measure body fat. We used to use calipers and measure the stomach- called it the pinch test. Now the Army uses a combination of waist, wrist, and neck measurements, plugs those into a table, and voila-you get a body fat percentage %. Not as accurate as the immersion test, but pretty good.

[Tobra]

I think a lot of it is genetics.

The gal I mentioned was a freak of nature physically. I have always gotten very fast results from exercise, lose excess fat, bulk up and get very defined quickly. I suspect this would not be the case any longer, or not as much so. That stuff goes away as you get older. It takes more work to maintain your lean muscle mass, flexibility and bone density as you age.

I would not mind seeing that table Chuck, probably only good for a certain age range.

[cbush]

try this link:

Army Body Fat Calculator

It does all the math for you. There is also a link to the regulation that includes a table of recommended weight by age.

Male standards are:

Age 17-20 - 20%
Age 21-27 - 22%
Age 28-39 - 24%
Age 40+ - 26%

And they will put you on the weight control program if you exceed.

[Tobra]

cool link, thanks CB

So if it is only 13% and I am 47, will they fatten me up to get me up to 26%?

That seems low to me, my BF being 13% I mean.

[cbush]

yea- 13% is low (but good) for our age. The standards above are the maximum allowed- not the recommended! If you are over that, and don't make progress losing the weight, you can/will be discharged. If one is 26% body fat- that means you are 1/4 blubber. Might want to take a look at becoming healthier.