The American Medical Association voted on Tuesday to adopt a new policy encouraging doctors not to rely solely on body mass index, a long-used but potentially misleading measure, when assessing weight and health. . Politics officially recognizes the “historical harm” of BMI and states that the metric has been used “for racist exclusion”.
“It’s a pretty significant change,” said Dr. Cynthia Romero, director of the M. Foscue Brock Institute for Community and Global Health at Eastern Virginia Medical School, which helped develop the new policy. “Now we really need to be more mindful and more holistic when it comes to patient care.”
The policy could be a first step in moving away from a model of medicine that urges people above a certain BMI to lose weight, regardless of the consequences those weight loss measures may have, a said Dr. Scott Hagan, an assistant professor of medicine at the University of Washington who has studied obesity and was not involved in the decision. “It’s a really big deal,” he said. Although the AMA is influential in the medical community, the new recommendation is only a suggestion to physicians, not a hard and fast rule to which they must adhere.
The association, one of the largest medical groups in the country, will now advise doctors not to use BMI alone to assess whether a patient is at a healthy weight. The AMA has suggested that doctors also consider factors such as visceral fat (the fat stored in the abdominal cavity and around the organs), body fat index (a calculation that uses hip circumference and waist), the percentage of fat, bone, and muscle in his body, and genetic and metabolic factors, such as abnormal blood sugar or thyroid tests.
The body mass index is a simple calculation with a complicated past. You generate it by taking your weight in kilograms and dividing it by the square of your height in meters. Critics have long argued that the metric is an inaccurate measure of health because someone with lots of muscle and little fat can have the same BMI as an obese person.
“BMI is just a very poor measure of general health,” Dr. Hagan said. “A person with a high BMI can be perfectly healthy.”
And where you carry weight matters, said Leslie Heinberg, director of the Enterprise Weight Management Center at the Cleveland Clinic. Abdominal fat is associated with higher rates of type 2 diabetes and cardiovascular disease, compared to fat around the hips, she said, a nuance the metric fails to capture.
“There are many concerns about how BMI has been used to measure body fat and diagnose obesity, but some doctors find it a useful measure in certain scenarios,” said Dr Jack Resneck. Jr., who resigned as AMA President. this month, wrote in a statement, adding that physicians should understand both the benefits and limitations of the metric.
At the population level, BMI is “probably the best we can do” for assessing large groups of people, said Iliya Gutin, program manager at the National Academies of Sciences, Engineering and Medicine and researcher affiliated with the University of Texas at Austin. who has also studied metrics and says he applauds the new policy. It is also inexpensive and effective.
But BMI is “not that magic or powerful number that dictates how healthy you are or how healthy you are,” said A. Janet Tomiyama, a psychology professor at the University of California, Los Angeles, who has studied BMI and said she was “shocked” by the new policy. “For a very long time I’ve been in this situation where the emperor has no clothes, where I just couldn’t understand why really smart doctors keep relying on something that was so clearly flawed. “
The new policy also points out that BMI was based primarily on data drawn from previous generations of non-Hispanic white people, making it difficult to apply the measure to a broader population.
Despite the decline in the metric, it has remained largely entrenched.
“A lot of our standards and guidelines have been built around this,” Dr Gutin said. “Once that happens, it’s very difficult to move the inertia.”