Body Mass Index has been a widely used health metric for nearly 200 years, but now, researchers are exploring a new alternative that could provide more accurate health information and account for race and gender — body roundness index, The New York Times reported Sept. 6.
BMI was created using information from white men and was never intended for medical screening. However, it has become the most widely used health metric, despite its limitations in determining muscle and fat. It also doesn't account for racial, ethnic, age, sex and gender diversity, the American Medical Association warned.
But a new metric — Body Roundness Index — is showing promise where BMI failed. The formula was developed by Diana Thomas, a mathematician and professor at the United States Military Academy in West Point, N.Y. She first described the metric in a 2013 paper published in the journal Obesity.
BRI measures how round a person is using a formula that takes into account height and waist, instead of weight. The formula, which ranks subjects on a scale of 1 to 15, may provide a better estimate for center-body obesity and abdominal fat, which is linked to increased risks of Type 2 diabetes, hypertension and heart disease.
A paper published in June in JAMA Network Open used data from 33,000 Americans between 1999 and 2018. It found those with a BRI score of 6.9 and up were at the highest risk of dying from cancer, heart disease and other illnesses. Those with a score under 3.41 also faced mortality risks that were 25% higher than those in the midrange.
"There's extreme variation in the population in the degree of muscularity of people, even those of the same weight," Steven Heymsfield, MD, a professor of metabolism and body composition at Louisiana State University's Pennington Biomedical Research Center, told the Times. "The percentage of fat can vary from 10% to 40% among people of the same BMI, age and sex. The BRI is a way of capturing these variations."