Last week I talked about why the number your scale gives you isn’t providing a full picture of your health. This week I’m going to tackle head-on another number that can often times be misleading: BMI.
The other day I was waiting in the doctor’s examining room. I must be carrying around a ton of suppressed memories in my head, because to this day the first thing I look for in the examining room is the drawer/cabinet with the needles. I hate getting shots. Done, found it. Now I can get all worked up when the doctor or nurse heads to that spot.
With that out of the way, I continued looking around, at which point a BMI chart caught my attention. I scanned the chart looking for my height, then I scanned across the chart finding my height and my BMI number. Sweet bag of Halloween candy!!! Actually, I might have muttered something slightly more R-rated because according to the chart I’m overweight.
Now, I’ll admit, I’m not as lean as I’d like (darn craft beer), but officially overweight? You’ve got to be kidding me! I’m 5’5”and average about 150 lbs. That gives me a BMI of between 25 and 26, depending on the day. To get down to the normal range I “should” be 144 lbs.
I know some of you reading this might be thinking, “What’s his problem? I wish I only had to lose six pounds to be healthy.”
But on my frame, with my physiology, six pounds is not an insignificant amount. To put it in perspective, when I was training 20 hours a week for an Ironman triathlon — that’s 140.6 miles of swimming, biking and running all in the same day — I was a 144 pounds.
I’m just gonna come out and say it: BMI is a %$&! number.
What is BMI?
Body mass index (BMI) is a measure of body fat based on height and weight. It was introduced in the early 19th century by a Belgian named Lambert Adolphe Jacques Quetelet. He was a mathematician, not a physician. He produced the formula to provide a quick and easy way to measure the degree of obesity of the general population to assist the government in allocating resources. In other words, it is a 200-year-old hack.
Yeah, there are so many reasons this is an unreliable metric.
It’s a ridiculous oversimplification to say that you should weigh a certain amount based on your height. There are far more important factors to consider. With BMI, there’s absolutely no distinction made between a pound of fat and a pound of muscle, even though that most certainly matters when assessing overall health.
BMI also doesn’t take into account the differences between genders or ethnicities, nor does it consider where the fat is stored, which is important because it’s actually visceral (“belly”) fat stored around your abdominal organs that’s linked to increased health risks. Having body fat alone doesn’t make you less healthy.
Fortunately, the general consensus now is that BMI simply cannot accurately predict health. But sadly this isn’t stopping doctors from calculating it and the medical world from using it to “target” you with weight loss interventions.
In the end, no single number — not your BMI nor the number on the scale — has the power to define you. We are far more complex than that.
If you want to know if you’re healthy, talk to your doctor about other types of measurements you can use, such as blood pressure, cholesterol and triglyceride levels, blood sugar, family history, and physical activity. By following the wrong numbers, you may end up chasing something you’ll never catch.
At FOR, we believe approaching the scale is part of a wellness journey to get curious why the number matters to you. If pressed for a measurable and proven system for determining body composition, we prefer the Waist to Height measurement commonly used throughout Europe.