Body Mass Index Means Nothing

I went into the doctor with my six year old girl. She does nothing but run and do pull-ups. She absolutely loves the jungle gym. The whole time we were there, the doctor said things like, "Wow, she sure is strong!" I was delighted and proud of course.

Then came the kicker.

At the end of the check-up, the doctor consulted his chart. "Oh, just so you know, her BMI is a little high."

"Well, yeah," I said, "but you just said she's super strong, that's probably just the extra weight of her muscle mass affecting the number right?"

At that point the doctor's authority conditioning kicked in and he decided to try and give me a lecture.

"Well, we find BMI is a great indicator of..."

I held up my hand to stop him, because I've heard all the nonsensical conditioning from corrupt pharmaceutical and insurance companies before.

"BMI is a ratio of weight to height. You get it from dividing your weight in kilograms by the square of your height in meters, right?"

He didn't answer, but I'm right (for the record, you can divide weight in pounds by the square of your height in inches if you multiply by the constant 703 to give you the proper conversion).

"It's just a ratio," I continued, "It doesn't provide definitive data about a person's health! Perfectly fit people with high muscle mass are going to have a high BMI."

"Well," the doctor said, recovering himself slightly, "we find it gives us a good barometer. The only people that get an inaccurate BMI reading are professional athletes and Olympic body builders..."

"Bullshit!"

That settled him down for a minute, so I continued.

"Look, I'm not a doctor, but I am a Physics teacher, and I know how ratios work. It's not like high muscle mass has no effect on your BMI, and then just magically starts being noticeable for Olympic athletes. An average person with high muscle mass will not have as high a BMI as an Olympic weight lifter, but their BMI will be higher than a person of similar size who is overweight."

He started giving me a really condescending shake of the head, "BMI gives us an accurate..."

"Can a person with a high BMI be in peak physical condition?"

"What?"

"Can a person with a high BMI be in peak physical condition? Is it possible? Does that scenario exist? Like with professional athletes?"

"Well, yes, but it represents a very small percentage..."

"Ok, if you admit that it exists, that it's possible for a person to be in great shape with a high BMI, then you can't know with certainty that a person is NOT in good shape on the basis of their BMI alone."

"Well..."

"So shut up about it. Don't mention it. BMI is just a scam used by the corrupt medical industry to fleece more insurance money out of people. With what I pay for health care, I think I deserve better treatment than for you to make decisions by measuring my height and weight and dividing the numbers by each other."

Yeah, at this point the doctor got up and left. But he was being the rude one, not me.

Even though your personal physician did not come up with the BMI scam, you do have the right to call them out on it. Sure, if you want to use BMI as an indicator to look for other health problems, that's fine, but BMI itself should never be brought up to a patient.

I get the same thing when I go in for a check up. Every year I run a few marathons, and I spend a fair amount of time in the gym. My BMI is usually around 30, every other aspect of my health from my cholesterol to my blood pressure is in great shape.

Nevertheless, at the end of every check up it's the same song, "We'd like you to get your BMI down." Somehow the part about me running marathons and lifting weights suddenly means nothing.

"Why?"

"Because the chart says it's too high."

"Well, my BMI is lower than that of Adrian Peterson, does that mean I'm in better shape than he is?"

They get irritated, but they have no right to. BMI is a joke and we need to pressure the members of our medical community to stop bringing it up.

If cholesterol is a problem, mention that.

If blood pressure is a problem, mention that.

But BMI, by itself means NOTHING!

FACT: Very fit, strong people have a high BMI. Shaming people for a high BMI is no different than any other form of prejudice.

Don't stand for it.