Calling BS on BMI

BMI-1 Maybe you found out the number in health class. Maybe you calculated it yourself after researching “healthy” or “unhealthy” weights on line. Maybe your doctor or psychologist used it to diagnose you (or mistakenly not diagnose you) with an eating disorder. However the method, it is safe to say we have all been confronted with this oh-so-irritating number at one point or another. Well today, I’m calling BS on BMI (body mass index).


The National Institute of Health says that your BMI is a measure of body fat based on height and weight. Any doctor worth their salt will tell you that it was never meant to be used as the sole determining factor of your physical health; however, it’s user-friendly format has contributed to our society doing just that. Companies offer financial incentives for employees with a “healthy” BMI, life insurance rates are higher for those with an “unhealthy” BMI, and, infuriatingly, health professionals routinely bring it up during everything from yearly physicals to gynecological exams.


The problem is, as was previously stated, BMI was never meant to be an indictor of health. It was designed for a random research study on the physics of “normal man” in the mid nineteenth century. As such, the BMI boundaries are arbitrarily produced and completely subjective. According to BMI, a difference of a decimal point will place you in the underweight, normal weight, overweight, obese, or morbidly obese category.  Clearly, this formula is far, far too simplistic. It does not take into account cholesterol, heart rate, or blood pressure, nor does it interpret relative proportions of bone, muscle, and fat in the body.


The fact is, whether you are completely healthy, in the depths of an eating disorder, or in recovery, BMI can feel like one big mind game, toying with fragile emotions and encouraging self-doubt and poor body image. I have personally never ever plugged my height and weight into an online BMI calculator and walked away feeling ok with myself.


So why do we still use it? There’s simply no single number that can represent “health,” so why are we hinging so much weight (pun intended) to this metric?  The only answer I can come up with is that it is convenient and simple, so insurance companies like it. But I don’t think I am alone in questioning why our society insists on continuing to measure our health (and self worth) on an invalidated heuristic statistical measure.  In fact, when it comes to our diet-obsessed culture, the last thing we need is an oversimplified number deeming us “unhealthy” without accounting for any of pieces of physical wellness (i.e the ones that actually matter).


So in conclusion, my final message to everyone (including myself) is this: do not let your BMI (or weight, or jean size) validate or invalidate you. A number does not define your health, self worth, recovery, or anything else. You are so, so much more.