5 X Reasons to Say BYEEE to the BMI

Let's all boycott the BMI!? Say what?!

BMI is it really the golden standard for health assessment? Let's break it down. 🧐

At any point in your life have you had to come face to face with society's definition of health? I am talking about the superficial number that your gravitational pull to the earth gets measured by. AKA your body mass index (BMI). 

Maybe you found it out through an uneducated doctor who happened to mention it to you, or maybe you even sought it out using an online calculator, or perhaps a treatment center used it to track your "progress". 

Maybe, pre-DSM-5 it was used as a way to diagnose your eating disorder. Or not diagnose you. (OOF do we have a long way to go as a society) But aside from all the BS about the BMI,  is there even a scientific backing for this formula that is so commonly used in healthcare as a measure of health? I did some research on the subject and decided to share my results with all of you!

Goals: hopefully by seeing it’s incredible inaccuracies you will be more skeptical of BMI and not let your BMI validate or invalidate you.

Reason 1 to Boycott the BMI:  It's NOT even designed for its current use

Flashback to the mid-19th century. 

Picture this: Belgian mathematician, astronomer, and statistician Adolphe Quetelet derived the Quetelet Index. He had ZERO interest in obesity when he came up with the index. 

As a pioneer in the field of  ‘social physics’ Quetlet wanted to define the characteristics of the ‘normal man’ using mathematical analysis and lingo. 

He used data from the heights and weights of the French and Scottish armies to show that most cases fell within the range defined as a person’s weight in kilograms divided by the square of the person’s height in meters. 

In 1835 he published his work in the book entitled A Treatise of Man and the development of his aptitudes. The index sat unused for nearly 140 years. 140 YEARS. Over a century later.

Until this man named Ancel Keys came along in 1972 and popularized it when he published a paper in the Journal of Chronic Diseases that coined the term "body mass index". 

Interestingly enough Ancel Keys explicitly said that the BMI is appropriate for very specific population studies. AND inappropriate for individual diagnosis. 

*Read that sentence again, and again, and keep reading it until your brain makes the connection that it is and never was appropriate for individuals.*

Reason 2: One’s health should not be defined by a decimal point

The BMI uses very sharp, rigid, no wavering boundaries that hinge on a decimal point to determine if someone is underweight, ideal, overweight, and or obese. A focus on only a number takes away from other important indicators of health such as diet, exercise, and lifestyle. (Not to mention the ridiculousness of putting people into boxes based on an arbitrary number that can fluctuate so much on any given day)

BMI category ranges (DSM 4 Criteria)

Below 18.5 = Underweight

18.5 to 24.9 = Ideal

25.0 to 29.9 = Overweight

30.0 and above = Obese

Reason 3: It is physiologically incorrect!

The BMI formula does NOT take into account the relative proportions of our bones, muscles, and fat in our body. Also, it does NOT distinguish between weight based on muscle in the body or weight based on fat. Both are needed for our bodies to function properly, AND, muscle does have a higher density, more mass per unit volume, than fat. This is why many people, especially, athletes for example, have high BMIs and are miss classified as overweight or obese.

Reason 4: It’s literally a one size fits all approach

BMI does NOT account for differences in people. There is no accounting for differences in race, gender, sex, genetics, lifestyle, growth curve, or even age. Like there is no personalization or taking into account any family history, lifelong body weight, or anything outside of arbitrary numbers. 

Reason 5: Not all fats are villains

The percentage of body fat or where fat is distributed is not considered or taken into account when it comes to BMI. Belly fat (fat around our abdominal organs) which can place people at a slightly higher risk of diseases like as diabetes or heart disease is very different from Peripheral fat (fat beneath the skin elsewhere in the body) which is associated with fewer health risks. 

Even society's narrow definition of thin people can have a high level of belly fat. This means they might be healthy by BMI standards, but internally they might be at higher risk of developing health problems.

The BMI is far from perfect, it comes with its share of inaccuracies.

There’s no single number that can represent a healthy weight. So why are we being held accountable to comply to this metric??

The only answer I could even remotely conclude is that it is convenient, and inexpensive, and insurance companies like it. It was also developed by white, heterosexual, men in an older time period. And, I feel like it’s time to get over the convenience factor and get innovative. 

With all the technological advances in medicine that have been made in just the last decade alone, it literally baffles me that we are still using this heuristic statistical measure. I conclude this post with the words of the inventor of the BMI himself.

The more advanced the sciences have become, the more they have tended to enter the domain of mathematics, which is a sort of centre towards which they converge. We can judge of the perfection to which a science has come by the facility, more or less great, with which it may be approached by calculation.

            -Adolphe Quetele

TLDR;

Though BMI offers simplicity, health is a complex, nuanced subject. Given the wealth of medical knowledge and technological tools available today, isn't it time we advocate for more comprehensive health metrics? We owe it to ourselves to look beyond an antiquated, one-size-fits-all model and embrace a more individualized approach to health.

🚀 If this resonates with you, join us in moving beyond BMI. Dive deeper, ask questions, and demand a more personalized health narrative. Health is personal. Let's ensure our metrics are, too.💡