The BMI scale isn’t a product of the modern health industry; it dates back to 1830, when it was designed by Adlophe Quetelet, a sociologist and statistician, to measure obesity rates in populations. His equation for determining a healthy weight range is pleasantly simple: You divide weight in kilograms by height in meters squared. This gives you a ratio that then fits into a weight range — anything below 18.5 is considered underweight, while anything 25 and up is considered overweight, with obesity kicking in at 30.
The problem, as many studies, including a new one led by UCLA researchers, is that higher BMI’s may not take into consideration body composition or other health factors. This means that while a person might appear to be in an unhealthy range, their weight actually isn’t affecting their health at all. When examining other markers that are indicative of general health, the researchers reported that nearly 30% of those at a supposedly “healthy” BMI range were actually unhealthy, while 15% of people considered “very obese” were quite healthy.
The system notoriously fails professional athletes, as their heavily-muscled bodies can actually be quite low on fat, but score high on the BMI index because of the greater weight of muscle and the sheer amount of it they’re carrying. Using the heights and weights listed by the NFL, NPR even discovered that the entire roster of the Denver Broncos would be considered obese going by BMI alone.
So it seems like the days of Quetelet’s antiquated scale are numbered, which is actually a good thing. According to the New York Daily News, the faulty BMI measurement tool is sometimes used by health insurance companies to determine coverage rates, which probably sucks for athletic pros. While no replacement scale has really been implemented, it’s good to know researchers are leaning toward relying on more holistic approaches to understanding health at last.