Behind the BMI: A History and Why The AMA is Discouraging its Use

Have you ever heard the information that the American Medical Affiliation (AMA) has publicly declared that the physique mass index (BMI) is an imperfect measure and is discouraging its use by physicians?

We all know that fats persons are handled otherwise, not supplied with evidence-based care, fatally misdiagnosed, unable to donate their bodies to science, denied entry to sure medical therapies, and prescribed weight-loss as a cure-all based mostly on solely their weight and BMI. This coverage change by the AMA occurred in June and is lastly a step in the appropriate route for the medical discipline. 

A brand new coverage was adopted by the AMA recognizing the problems with BMI due to the historic hurt of this measure together with its racial bias, which we are going to talk about shortly. The coverage additionally states there are limits to what the BMI takes into consideration and it ought to NOT be used as a sole criterion of denial by insurance coverage corporations. 

The report by the AMA Council on Science and Public Health states, “Quite a few comorbidities, way of life points, gender, ethnicities, medically important familial-determined mortality effectors, length of time one spends in sure BMI classes and the anticipated accumulation of fats with getting old are more likely to considerably have an effect on interpretation of BMI information, significantly in regard to morbidity and mortality charges. Additional, using BMI is problematic when used to diagnose and deal with people with consuming problems as a result of it doesn’t seize the total vary of irregular consuming problems.”

The Historical past of BMI

Let’s get into a few of the historical past behind the BMI and clarify why the AMA is true on the right track with their new suggestions. The system later used to calculate BMI was created by a mathematician within the early nineteenth century named Lambert Adolphe Jacques Quetelet. On the time, it was known as the Quetelet Index.

The intent of his system was to have a fast and simple method to measure the final inhabitants, it was not meant for use on a person foundation and relies on information collected from generations of non-Hispanic white males. It doesn’t think about the particular person’s gender, race, or ethnicity. 

Completely different ethnicities and races have completely different “wholesome weights” based mostly on analysis. In response to the US Department of Health and Human Services’ Office of Minority Health (OHM), black girls have the best charges of “weight problems” and being “obese” in comparison with different US teams.

However this probably implies that because the BMI didn’t embody Black males or girls, or girls usually, a wholesome weight for the Black group could also be completely different. In reality, a 2003 examine printed in The Journal of the American Medical Affiliation (JAMA), confirmed that increased BMIs are usually extra ideally suited for Black folks.

In China and Japan, they’ve modified the cutoff for the “obese” class from the US model, probably as a result of folks of Asian descent have 2X the probability of growing Kind 2 Diabetes than caucasians.

Within the late twentieth century, well being and life insurance coverage corporations changed their very own height-weight tables with the Quetelet Index and correlated an elevated quantity of physique fats with an elevated threat of coronary heart illness. This issues as a result of insurance coverage corporations then used this data to find out an individual’s protection and docs used it as a method to decide if they might settle for a affected person at their follow. 

In a 1972 article known as “Indices of Relative Weight and Obesity,”Angel Keys gave Quetelet’s measurement its trendy identify, the BMI, and in addition supported its use. Researchers, medical professionals, the federal government, and extra importantly- insurance coverage corporations, wished a easy method to observe “well being threat” among the many US inhabitants. 

Keys analyzed the adiposity-density and subcutaneous fats thickness of seven,400 males from 5 European international locations, used the Quetelet index, and got here up with the BMI as a easy method to measure physique weight in relation to peak.

In 1985, the Nationwide Institutes of Well being (NIH) began to make use of BMI as a method to “establish weight problems.”  So not solely is that this measure based mostly on an previous system, not getting used for its meant use, and based mostly on solely white males, it additionally makes no allowance for various physique proportions when it comes to the quantity of bone, muscle, and fats within the physique. Somebody with robust bones, plenty of muscle, and low physique fats may have a excessive BMI.

How BMI is utilized right this moment tends to make the belief you can’t be wholesome when you’re over a sure weight. However there are individuals who fall within the “overweight” class based mostly on BMI and are fully metabolically wholesome, simply as there are individuals who might fall into the “regular weight” class are metabolically unhealthy. 

The Influence of the AMA’s New Coverage

When the information first got here out in regards to the AMA’s new coverage, our first thought was “what in regards to the new AAP Pediatric Tips?!” You possibly can learn extra about these pointers here. However principally, in January of 2023, the AAP put out new pointers recommending behavioral therapy, weight problems medicines, and even bariatric surgical procedure to youngsters. These pointers are based mostly on the kid’s BMI.

So if the AMA is recommending BMI not be used alone and is acknowledging that it’s not an awesome scientific measure of well being, how does that have an effect on the AAP’s suggestions? Will these change? Or will youngsters be additional stigmatized for his or her weight?

It’s our hope that with the AMA’s new coverage, which means the medical world is altering. We hope it implies that extra suppliers will undertake a Wholesome at Each Dimension mannequin and that this adjustments what suppliers are taught in medical college about fatness.

We hope it will result in evidence-based look after each particular person, no matter measurement.