5 BMI Myths Busted
Photo By: Emma Simpson on Unsplash
In the US, the BMI (Body Mass Index) is typically used as a measurement of body fat by primary care physicians. I’m a mental health counselor who believes in weight-inclusive care and radical self-love as a lens from which to provide treatment. My experience as a therapist began at the National Eating Disorders Helpline, and was followed by training at an eating disorders day treatment program in Boston. I was fortunate to learn about why the BMI is so harmful and is certainly not a reliable tool for measuring body fat. Below, I will bust some myths about the BMI, share resources to gain a further understanding, and provide alternative options for taking care of your health.
Myth #1 The BMI is a reliable measure of health
The BMI is essentially a ratio of your weight and height. Its accuracy is largely disputed by a significant amount of research. It doesn’t differentiate between muscle weight, bone mass, or fat. Due to this, many professional athletes would find themselves in the obese range. The CDC outlines this in its description of the BMI, and lists other measures that provide more accuracy. Unsurprisingly, doctors are incentivized to use the BMI because the alternative measures are more expensive.
Myth #2 The BMI is a medical tool.
Actually, the BMI was created in the 1830s by Adolphe Quetelet, who was not a medical scientist, researcher, or physician. He was a mathematician hired by the government to create a measurement of obesity in the general population specifically for the purpose of “assisting the government in allocating resources”. Quetelet himself said the formula should not be used to measure fatness in an individual.
Myth #3 We should all be aiming for the “ideal” body weight range in the BMI.
The ideal body weight was invented long after the BMI in 1974 specifically for anesthesiologists to estimate drug clearance (the rate at which a drug is removed from blood plasma). It was never intended to indicate the weight that any individual “should” be. The made up nature of the BMI ranges are even more evident in the 1998 decision by the National Institute of Health to lower the overweight range, which instantly re-categorized millions of people as “overweight”. This decision was based on a report funded by companies that were making weight loss drugs. So, if more patients were “overweight” and needed medicine “for their health” then the pharmaceutical companies could prescribe more drugs.
Furthermore, the language regarding an “ideal” body is harmful and pervasive as an idolized “perfect” range that every individual body weight is “supposed” to fall within. There is no ideal body. All body shapes and sizes are worthy of love and acceptance. The Body Is Not An Apology is my favorite book by Sonya Renee Taylor that helps readers to dismantle body shame and to cultivate compassionate relationships with our bodies.
Myth #4 We can control our weight.
Weight Set Point Theory states that our bodies deliberately maintain a narrow weight range at which the body optimally functions. The body retains energy specifically by functioning against weight loss below this range, and this is why it’s very difficult to lose weight. There is significant research (see: The Biggest Loser study and the Minnesota Starvation Experiment) that shows while people can intentionally lose weight, most will eventually regain most of, all of, or even more than they initially lost.
Myth #5 The BMI standard applies to everyone.
The BMI was an equation created to represent the trends of white men. The white male model of health was the norm until gender-based differences were finally researched in the 1990s. It does not account for the inherent diversity of body shapes. For example, the percentage of body fat or muscle mass can vary by race and ethnic group, which leads to numerous overestimations and underestimations of health risks, especially in BIPOC individuals. This also doesn’t even begin to account for the lack of medical research regarding trans healthcare.
If there is such hard evidence against the BMI, what is a better lens through which we can see our health?
Health at Every Size® provides a holistic view of health. Their principles include: supporting physical activity for all bodies, respectful care, eating for well-being, supporting health policies that equalize access to care, and weight inclusivity. HAES® also has a list of healthcare providers who promote these principles.
The National Eating Disorders Association offers resources and support for everything from negative body image concerns to eating disorder treatment (including free and low-cost options!) They also offer a map of treatment providers across the USA including nutritionists, dieticians, and eating disorder therapists.
I went to a new doctor for a physical recently and was surprised to find that she recommended I lose weight solely based on my BMI (especially after everything else about my health was normal!) It’s an upsetting, frustrating, and even enraging experience to be given advice by a medical professional that is based on fatphobia. I am privileged enough to have been more educated than my doctor on this topic, but I know that’s not the case for most people. I want to use my anger to fuel my efforts to help myself and other people (especially women) experience liberation from weight stigma. It matters to me that you could be able to walk into a physical and tell your doctor why the BMI is an outdated and highly disputed measurement of fat. It matters to me that you can say “no” if they ask to talk about your weight. It matters to me that you can find a doctor who will see you as a whole person and not just a number on the scale. We should never settle for less than the healthcare we truly deserve.