Why BMI is Bullshit, Especially for Athletes
BMI.
Even just reading those three letters can trigger some strong emotions. It can bring back memories of medical diagnoses (or lack thereof) that were more harmful than helpful. So much of our medical system relies on what someone’s BMI “indicates” for their health. But where did BMI even come from? And does it have anything to do with our performance as athletes?
The history of BMI
The BMI formula was created in the 1830s by Lambert Adolphe Jacques Quetelet, a Belgian astronomer, mathematician, statistician, and sociologist.
Read that again.
The BMI formula was created in the 1830s by Lambert Adolphe Jacques Quetelet, a Belgian astronomer, mathematician, statistician, and sociologist.
Yep, you read it right. Quetelet created this equation almost two hundred years ago. He wasn’t a health professional. He never intended for the BMI formula (then called the Quetelet Index) to be used for medical assessments. He was actually doing a study on the average man and was looking for a way to standardize his research. Funnily enough when he mentions this in his study, he also points out that there are too many physical factors to account for because humans are so diverse, so he must’ve been trying to simplify things.
Notice how the BMI formula only takes weight and height into consideration. What about ethnicity? Gender? Age? Body composition?
The BMI formula that modern society so desperately (and obsessively) clings to isn’t all that it’s cracked up to be, and it’s not a tool that I use with my own clients in nutrition therapy sessions.
The Adoption of BMI into the American Medical System
BMI began to be used widely to determine ‘health’ in the 1950s when an insurance company noted that more and more claims were coming from policy holders with larger body sizes and they wanted to use these charts to determine premiums - to make a higher profit.
Ancel Keys coined the term BMI and decided to use these charts to help set standards in research, but even he recognized that it was not the best indicator of body fat mass. In 1998, overnight around 25 million became ‘overweight’ that had previously been deemed ‘healthy’. How in the world is that even possible? The World Health Organization (WHO) made a new definition of ‘healthy’ by decreasing the previous ‘healthy’ BMI of 27.8 for men and 27.3 for women BMI to 25.
That’s all it took. No change in exercise or eating habits. No change in stress levels or medical conditions. Just a change in definition.
BMI and Athletes
BMI gets especially tricky when athletes are involved, since it doesn’t actually determine the lean mass to fat ratio or even the bone structure on a body. So you could be at the peak of your physical performance with a lot of muscle mass and be way over the ‘healthy’ range on the BMI scale.
Let’s take two iconic athletes: LeBron James and Tom Brady.
I don’t think anyone would say either of them are out of shape or ‘unhealthy’ - LeBron is a 16-time NBA All-Star, and Tom is a six-time Super Bowl champion.
What are their BMIs? LeBron clocks in with a BMI of 26.8 and Tom Brady has a BMI of 27.4, both of which are considered ‘Overweight’.
Yet there are so many athletes who get caught up in the BMI stigma of thinking they aren’t ‘healthy’ but don’t realize that it’s because their bodies are built differently and/or have more muscle.
Have you been caught up in worrying about your BMI?
Reach out to me and we can work together to find realistic and compassionate ways to determine your overall health rather than relying on a quickly calculated number.
