Get it...how much weight should you put into your BMI... you're welcome for the bad joke.
Before you read any further: BMI should not be the only data point you look at when judging your health and health risks. You’ll learn below how flawed it is, but also, why the US health system still uses it.
At its roots, BMI is a measurement of body composition that doctors use to determine risk factors for health conditions based on weight. BMI is also one of the health industry’s favorite buzzwords. And while there are reasonable concerns about the implications of a high or low BMI, there’s also just as much gray area with the number relating to your BMI as there is the number on the scale.
Unfortunately, the same connotation that exists with an “overweight” weight also exists with having a BMI number that signifies that you’re overweight. However, there’s a lot you’re not being told just from that number alone. So, let’s dive into the history and actual meaning of a BMI.
WHAT IS BMI, ANYWAY?
BMI stands for Body Mass Index, it's a formula that’s calculated by dividing your weight by your height that gives you your overall body fat percentage. Typically, anything under 18 is low and 25 is overweight. Anything above 30 is obese according to the BMI scale. Of course, the BMI scale wasn’t invented to make us feel bad about ourselves, and in some cases can be a helpful tool to catch red flags that would signify diseases that may come from obesity or malnutrition.
You can calculate your BMI here, but please remember that there is so much more that goes into your health than this number. Many of our coaches by these standards are “overweight” because they are so muscularly dense.
A RUN DOWN ON BMI’S HISTORY
BMI has been utilized in the medical industry for over 200 years. Adolphe Quetelet, a Belgian astronomer and mathematician came up with the idea in the 1830s while studying the characteristics of the “average man.” Ironically, he didn’t study health and was not a physician. He created this formula as a way to give a quick and easy measurement of obesity in the general population. This measurement was a way for the government to allocate resources. During his research, Quetelet was only measuring “healthy” Western European men. This has led many to question the formula and if it’s even a useful measurement for modern-day.
THE MODERN VIEW ON BMI
One of the major issues with BMI is that it doesn’t take into account fat versus muscle. Let’s say you’re a woman that is 5’0 and 145 lbs. Technically, your BMI would be over 28, meaning you’d be pretty close to moving out of the overweight category and into the obese category. Let’s then say 80% of your body weight is muscle. Clearly, you’re not actually experiencing the health concerns surrounding obesity. Additionally, as you get older and lose more muscle, you may experience changes in weight, but that also doesn’t necessarily mean your body will align with those changes.
We still use BMI for two main reasons. One, it’s not always wrong. Two, it’s less expensive than full-body scans, MRIs, and other diagnostic tests. It’s similar to that of a scale, a pound on a scale is a pound. That’s not always a bad thing, especially if you’re gaining muscle. However, this can still indicate correct answers for a generally large number of people.
SO, HOW MUCH WEIGHT SHOULD I PUT ON MY BMI?
While BMI is a helpful tool in understanding a general snapshot of our health, it’s not the end all be all in determining our wellbeing. It has since been learned that BMI is different depending on your ethnicity. For example, Polynesians are generally healthier at a higher weight range, while Asians are healthiest at a lower BMI. Women also carry weight differently than men, making our BMI slightly higher. While this measurement may give an average idea of body fat, it also ignores lean muscle mass, which is a very important factor in a person’s body composition.
New research shows that measuring waist circumference can be a better determining factor for health issues. However, many medical professionals are moving away from weight loss and focusing more on living an overall healthy lifestyle. Staying active, eating a well-balanced diet, and staying hydrated are much more important than a number from an outdated formula anyways!