Arm Yourself: Why I Hate BMI

I hate the standard BMI. I’ve always been perfectly blunt about, am still blunt about it, and will always be blunt about it.

For those of you who don’t know what BMI is, it is the


To find BMI, you can either use a simple online calculator, like the one found here or you can use this formula and do it on your own.

Metric Formula
Metric Formula
Imperial Formula
Imperial Formula

And then you take what you get and you categorize yourself as underweight, normal, overweight or obese according to these standards:

  • Underweight – BMI less than 18.5
  • Normal – BMI between 18.5 and 24.9
  • Overweight – BMI between 25 and 29.9
  • Obese – BMI 30.0 and greater

Simple enough? Sure. Reasonable approximation of your actual body fat? I say no.

By comparing your weight to your height and assigning it a value that is then based on an outdated scale, it doesn’t provide anything close to a comprehensive portrait of the human being measured. Think I’m being a bit judgmental and overreaching about how dated it is? It was developed by Belgium Statistician Adolphe Quetelet approximately 150 years ago.

It does not take into account:

  • Greater bone density
  • Many deviations in body height
  • Muscular development

It was created during a time when physicians needed to be able to make quick calculations without calculators. Today, not only are calculators readily available (Hell, I linked one in this very article), but so is the following technology, and many people have access to them via their health insurance (and in my case my military gym access):

  • Bioelectric impedance analysis
  • Hydrostatic weighing
  • DEXA scan
  • Body taping and comparison

Does it seem like my gripe might be a little more personal than just the facts? It sure is.

Being in the U.S. Army, every time we take an APFT (Army Physical Fitness Test), we have to have our height and weight measured first. If we measure over our acceptable BMI (anything above normal, and they have a chart that shows the maximum weight for the cross section of your height and weight), we have to get taped. There is a bit of a stigma attached to this. I’ve learned to get over it, but it’s there. Then, for males, they tape our neck and waist. If we pass the acceptable measurements there (waist minus neck and referenced on a pre-approved chart), we pass.

The hitch here is that:

  • If you’re muscular, you still get the stigma of having to be taped
  • If you’re actually overweight or obese, you can get away with it by making your neck swell up the day of
  • There are people who can perform the APFT better than average who don’t pass either (I’ve seen a First Sergeant brag to a soldier he was currently counseling for being 1% over… about how he cheats his Santa Claus sized belly by developing a bigger neck… and he doesn’t take the APFT)

I know that I personally was already at the tipping point when I was at my weakest/skinniest. The moment I added any muscle, it tipped me over to “overweight” and I had to start getting taped. However, I wear it as a badge of honor. But I am by far not the only one with an ounce of muscle who has this issue.

See: Borderline Overweight
See: Borderline Overweight

My other problem is with this being used as a medical standard, as well. A few of my friends, including a long time friend who is in the medical field has explained that it is only used as a preliminary gauge for possible heart problems. A quick snapshot. This, for me, is the one acceptable use of this formula, which (in my opinion) is as it should be. Why? Because you can’t base a patient’s medical direction on it without taking additional steps in any case. You’re either going to resort to other measures or conduct further tests. In other words:

Did you pass it? Great. Move on.
Did you not pass it? Great. Time for more tests to make sure there’s an issue.

To me, that means it’s an almost completely unnecessary step, with a ton of exceptions and no real direction. Nevermind that even in that example, people who pass the test may actually be at higher risk than those who do not pass it. They just passed this one arbitrary test.

Now, yes, if you have a BMI of 34 like The Rock and you don’t look like him… you’re probably obese. But there is a lot of grey area before that.

Finally, many people place too much emphasis on it out of a lack of education about the body and fitness.

TLDR/In short/In summary:

  • Outdated
  • Too little data involved
  • Too many exceptions
  • Too many consequences in certain fields
  • Ignores people who might have issues but passed it
  • Many better options out there
  • The uninformed use it to judge themselves

Until Next Time

Jacob Summers (SuperSoldier) is a certified personal trainer, but not a medical expert in the field of nutrition. 


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