Have you heard the news that the American Medical Association (AMA) has publicly declared that the body mass index (BMI) is an imperfect measure and is discouraging its use by physicians?
We know that fat people are treated differently, not provided with evidence-based care, fatally misdiagnosed, unable to donate their bodies to science, denied access to certain medical treatments, and prescribed weight-loss as a cure-all based on solely their weight and BMI. This policy change by the AMA happened in June and is finally a step in the right direction for the medical field.
A new policy was adopted by the AMA recognizing the issues with BMI because of the historical harm of this measure including its racial bias, which we will discuss shortly. The policy also states there are limits to what the BMI takes into account and it should NOT be used as a sole criterion of denial by insurance companies.
The report by the AMA Council on Science and Public Health states, “Numerous comorbidities, lifestyle issues, gender, ethnicities, medically significant familial-determined mortality effectors, duration of time one spends in certain BMI categories and the expected accumulation of fat with aging are likely to significantly affect interpretation of BMI data, particularly in regard to morbidity and mortality rates. Further, the use of BMI is problematic when used to diagnose and treat individuals with eating disorders because it does not capture the full range of abnormal eating disorders.”
The History of BMI
Let’s get into some of the history behind the BMI and explain why the AMA is right on target with their new recommendations. The formula later used to calculate BMI was created by a mathematician in the early 19th century named Lambert Adolphe Jacques Quetelet. At the time, it was called the Quetelet Index.
The intent of his formula was to have a quick and easy way to measure the general population, it was not meant to be used on an individual basis and is based on data collected from generations of non-Hispanic white men. It does not consider the person’s gender, race, or ethnicity.
Different ethnicities and races have different “healthy weights” based on research. According to the US Department of Health and Human Services’ Office of Minority Health (OHM), black women have the highest rates of “obesity” and being “overweight” compared to other US groups.
But this likely means that since the BMI didn’t include Black men or women, or women in general, a healthy weight for the Black community may be different. In fact, a 2003 study published in The Journal of the American Medical Association (JAMA), showed that higher BMIs tend to be more ideal for Black people.
In China and Japan, they have changed the cutoff for the “overweight” category from the US version, likely because people of Asian descent have 2X the likelihood of developing Type 2 Diabetes than caucasians.
In the late 20th century, health and life insurance companies replaced their own height-weight tables with the Quetelet Index and correlated an increased amount of body fat with an increased risk of heart disease. This matters because insurance companies then used this information to determine a person’s coverage and doctors used it as a way to determine if they would accept a patient at their practice.
In a 1972 article called “Indices of Relative Weight and Obesity,”Angel Keys gave Quetelet’s measurement its modern name, the BMI, and also supported its use. Researchers, medical professionals, the government, and more importantly- insurance companies, wanted a simple way to track “health risk” among the US population.
Keys analyzed the adiposity-density and subcutaneous fat thickness of 7,400 men from 5 European countries, used the Quetelet index, and came up with the BMI as a simple way to measure body weight in relation to height.
In 1985, the National Institutes of Health (NIH) started to use BMI as a way to “identify obesity.” So not only is this measure based on an old formula, not being used for its intended use, and based on only white men, it also makes no allowance for different body proportions in terms of the amount of bone, muscle, and fat in the body. Someone with strong bones, a lot of muscle, and low body fat will have a high BMI.
How BMI is applied today tends to make the assumption that you can’t be healthy if you’re over a certain weight. But there are people who fall in the “obese” category based on BMI and are completely metabolically healthy, just as there are people who may fall into the “normal weight” category are metabolically unhealthy.
The Impact of the AMA’s New Policy
When the news first came out about the AMA’s new policy, our first thought was “what about the new AAP Pediatric Guidelines?!” You can read more about those guidelines here. But basically, in January of 2023, the AAP put out new guidelines recommending behavioral treatment, obesity medications, and even bariatric surgery to children. These guidelines are based on the child’s BMI.
So if the AMA is recommending BMI not be used alone and is acknowledging that it is not a great clinical measure of health, how does that affect the AAP’s recommendations? Will those change? Or will children be further stigmatized for their weight?
It is our hope that with the AMA’s new policy, this means that the medical world is changing. We hope it means that more providers will adopt a Healthy at Every Size model and that this changes what providers are taught in medical school about fatness.
We hope this will lead to evidence-based care for each and every person, regardless of size.