The American Medical Association (AMA) has a new policy on Body Mass Index (BMI), that changes the way doctors, patients and insurance companies approach weight and health.
Some people may have likely stepped on a doctor’s scale at some point and got the heebie-jeebies over BMI – weight divided by height to the power of two. A Belgian mathematician, Adolphe Quetelet, came up with it in the 1830s when statistics was a new field of study and caught his interest. Quetelet gathered data of white men's heights and weights “to determine the ‘average’ man,” a standard that excluded women and people of color.
Some 200 years later, the AMA has determined that BMI is an imperfect measure because it does not directly assess body fat, and is misleading about its effects on mortality rates.
The AMA Council on Science and Public Health acknowledged that BMI excludes gender and racial differences.
“There are numerous concerns with the way BMI has been used to measure body fat and diagnose obesity, yet some physicians find it to be a helpful measure in certain scenarios,” Dr. Jack Resneck, Jr., immediate past president at the AMA, said in a statement. “It is important for physicians to understand the benefits and limitations of using BMI in clinical settings to determine the best care for their patients.”
For adults, measuring BMI along with waist circumference may be a better way to predict weight-related risk, AMA advised.
“We’ve been waiting for this because BMI is only a screening tool, it’s not a diagnostic tool,” said Dr. Veena Vani, an internist in Glastonbury. “And when it comes to treating a patient with [an] elevated body-mass index, you look at a lot of other factors in deciding how to treat the patient.”
Those factors include waist circumference that indicates visceral fat, and muscle weight versus weight of fat.
“I think this is really going in the right direction, because BMI [was used] as a criteria to deny care for a patient who really needs a procedure,” Vani said. “At least now, [insurers and surgeons] will be looking at other factors in totality.”
Other criteria such as gender, race, age, genetics, and even, occupation.
“We see higher rates of eating disorders in veterans because the majority of those individuals are overweight,” said Robin Masheb, professor of psychiatry at the Yale School of Medicine. “They are referred for weight management services and their eating disorder is overlooked.”
That’s because, Masheb said, doctors may not realize that the problem is not weight, but an eating disorder that requires treatment in order to help with weight management.
The AMA said 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.
“BMI is (also) not able to tell about an individual’s health risk for obesity related diseases like diabetes; it can give us an idea at the population level, but it's not going to tell you for the patient who comes into your office, looking at that just by itself,” she said.
So Masheb, director of the Veterans Initiative for Eating and Weight at the VA Connecticut Healthcare System in West Haven, and her team developed an alternate measure to address the limitations of BMI, called the Weight and Eating Quality of Life (WE-QOL) Scale.
