When you go to see your provider for your annual check up, there are certain lifestyle changes that they might recommend you make — limit your alcohol intake, sleep more, and maybe, if your BMI is over 25, lose some weight.
But while BMI is one of the most commonly accepted measurements of health, this calculation has a problematic history and a flawed application. Let’s break down the fraught history behind BMI.
BMI: The backstory
BMI (first called the Quetelet Index) was invented by a Belgian mathematician named Lambert Adolphe Jacques Quetelet in the early 19th century. He set out to find the “average man” by studying the height and weight of (mostly) European men. His work did not include women or people of color.
A century later, BMI — a calculation of weight (in kilograms) divided by height in (meters squared) — was picked up by health insurers and medical providers in the U.S. They used BMI to create weight categories (underweight, normal weight, overweight, obese, and morbidly obese) in order to determine individuals’ insurability.
Okay, this sounds questionable, but does it work?
BMI is not a very useful health indicator. There are a few reasons why.
1. BMI was originally created to indicate population health, not to determine individual health.
Quetelet was a statistician. His intention was to collect large amounts of data to uncover population-level trends, not to assess an individual’s health or risk factors.
2. These categories are problematic for individuals who were left out of the original studies
Given the fact that so many groups were excluded from the development of BMI in the first place, it doesn’t make much sense to apply it to them retrospectively. Further, BMI suggests that there is an ideal height/weight ratio. This is simply not true.
3. BMI equates muscle, fat, and bone
The body is made up of (among other things): bones, muscles, and fat. BMI groups all these categories together into one, treating bone, muscle, and fat the same. Not only that, but which out of these three parts of the body weighs the most? Bone. The least? Fat.
So is there a better way to calculate health?
There are alternative calculations of health informed by weight, but the issue at play here goes far beyond the biased history of BMI or its misguided application to individuals. Even weight itself is not a strong indicator of health and research has shown that simply changing one’s body weight is not a reliable measure of improvement in one’s health.
If you’re looking to feel stronger and healthier, there are things you can do, like starting a health promoting behavior.
Here are a few examples of health promoting behaviors
- Setting a goal to drink more water
- Figuring out what type of exercise you enjoy and doing it consistently
- Finding a mindfulness practice that helps you tune into your inner needs
- Intuitive eating: listening to your body’s requests for nourishing food
Setting goals like these – that are based on how you feel, how your body functions, and what you personally need to be living in a healthier body – is more reliably associated with improvement in overall health.
Providers that rely too heavily on BMI might be missing the whole picture of your health. If you’re concerned that your provider isn’t understanding the whole picture of your health, seek out a HAES (Health At Every Size) aligned healthcare provider. There are therapists, body image coaches, doctors, nurses, and dietitians who are all trained in HEAS. You deserve to feel seen and cared for by your provider, regardless of your BMI or the size of your body.
Reviewed by the Ovia Health Clinical Team
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Sources
- Brazier, Yvette. “How Useful Is Body Mass Index?” Medical News Today. MediLexicon International. September 6, 2021. https://www.medicalnewstoday.com/articles/255712.
- Jackson-Gibson, Adele. “The Racist and Problematic Origins of the Body Mass Index.” Good Housekeeping. Good Housekeeping. November 1, 2021. https://www.goodhousekeeping.com/health/diet-nutrition/a35047103/bmi-racist-history/.
- “Adult BMI Calculator.” Centers for Disease Control and Prevention. Centers for Disease Control and Prevention. January 21, 2022. https://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/english_bmi_calculator/bmi_calculator.html.
- “About Adult BMI.” Centers for Disease Control and Prevention. Centers for Disease Control and Prevention. August 27, 2021. https://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/index.html.
- The MNT Editorial Team. “BMI calculations and charts.” Medical News Today. Medical News Today. May 3, 2021. https://www.medicalnewstoday.com/articles/323586.
- Devlin, Keith. “Top 10 Reasons Why the BMI Is Bogus.” NPR. NPR. July 4, 2009. https://www.npr.org/templates/story/story.php?storyId=106268439.
- Eknoyan G. Adolphe Quetelet (1796-1874)–the average man and indices of obesity. Nephrol Dial Transplant. 2008 Jan;23(1):47-51. doi: 10.1093/ndt/gfm517. Epub 2007 Sep 22. PMID: 17890752.
