When you go to the doctor, one of the things that is probably listed on your chart is your Body Mass Index (BMI). Because it is talked about so commonly at doctors’ appointments and we see it all the time, it must be a super duper accurate, very scientific measure of health, right? WRONG. BMI is outdated, and it is not an accurate measure of health.
With all of the emphasis that is placed on BMI, it is easy to forget that it is just a ratio of one’s weight and height. That’s it!
Unfortunately, it has become all too common for people to be labeled and classified in the healthcare system based on their BMI. This can lead to assumptions being made by doctors about your health habits, and can alter the course of your care.
This is pretty unfair if you ask us. That is why here at NourishRX and within the NourishRX PATH, we promote a Health at Every Size (HAES) approach- we believe that you are more than a label and a number.
History of BMI
Waaaay back in the 1800’s, a mathematician and sociologist named Adolphe Quetelet was on a mission to try to classify what he called “the average man.” In other words, he was just trying to find the mathematical mean of a population. He did this by measuring men’s height and weight, and finding what the “average size of a man” was.
Now, let’s quickly note that Quetelet was not a physician; he wasn’t in the health field at all! This is why he made it a point to say that he did not intend BMI to be a marker of health. He designed BMI as a statistical measure and nothing more.
It was not until the early 1900’s when BMI was adopted as a health measure. To this day, it is something that is used in doctors’ offices and by insurance companies to determine health status. However, as we stated before, there are a number of reasons that BMI is not an adequate measure of health, and should not be used to label people as “healthy” or “unhealthy.”
Side note: Maintenance Phase has a great podcast episode that explains this in more detail
Now let’s dive a little deeper into some other reasons BMI is not an adequate measure of health.
5 Reasons why BMI is Outdated
1. BMI is not inclusive
When Quetelet conducted his study to find the “average man,” he included western European men only. That means no women, no people of color, and no transgender folks.
As we know, genetics plays a huge role in the size and shape of our bodies, so using BMI for people other than Western European men doesn’t quite line up. It’s like using a hammer to screw in a nail - it’s the wrong tool!
2. BMI categories are arbitrary
With the data collected by Quetelet, the healthcare system has taken it upon themselves to come up with a classification system: “underweight,” “normal,” “overweight,” and “obese.”
However, studies show that folks in the “overweight” category have a similar risk of disease as those in the “normal” category, on the whole. In fact, for older adults, being in the “overweight” category has been shown to be protective against common age-related diseases.
Further, let’s remember that it is possible to be sick or to be diagnosed with a condition in any BMI category. Hmm..it’s almost as if you can be healthy at any size!!
3. BMI is too simplistic
As we mentioned before, BMI takes into account two things: height and weight. There are so many other factors that can contribute to wellbeing: the environment you live in, movement, sleep patterns, family history, stress, and weight stigma, to name a few! It is not until all of those factors are taken into account that someone can make an accurate determination of health.
4. BMI perpetuates weight stigma
Picture this: a doctor takes a look at your BMI, and immediately dives into a conversation about “exercising more and eating better” without first asking about your habits, self-care, or mental health. An assumption has been made based on your body size. This is a phenomenon called weight stigma.
Again, BMI is used to tell us one thing: if an individual is above or below the average height and weight of a population. It does not account for other health-promoting behaviors or factors that can affect health. When assumptions are made based on BMI, it is easy to miss important details about one’s health that could completely change their course of care.
5. Does not account for body composition
By now, you can probably see that BMI is a flawed and incomplete measure. Because it only accounts for height and weight, it does not account for body composition. Muscle is more dense than fat. As a result, people with large amounts of muscle mass can find themselves in the “overweight” or “obese” category.
As stated before, when someone falls into these higher categories of BMI, they are often labeled as “unhealthy” and at risk for disease. But wait - strength training and movement are health-promoting behaviors that lower the risk of disease. Huh.
Remember - you are more than your BMI. Our team of dietitians here at NourishRX uses a number of factors to assess your health and overall wellbeing. We take a look at measures of health such as your stress levels, the adequacy of your food intake, your relationship with movement, and your feelings towards food. These things not only give us a picture of your physical health, but of your mental health as well.
To find out more about how to use these measures to assess your health and happiness, reach out to our team! Additionally, when you join the NourishRX PATH, you will learn more about all of the different factors of wellbeing (and trust us - BMI is not one of them).