New research suggests an updated definition of obesity might indicate that more people have the disease than previously estimated.
It’s currently estimated that 40% of adults in the United States are obese. However, much of the existing research relies on body mass index (BMI), a measure comparing weight to height. Many doctors consider BMI an imperfect tool to define obesity because it does not differentiate between excess weight and body fat or muscle and bone.
Last year, an international commission defined ‘clinical obesity’ as a chronic illness characterized by tissue and organ dysfunction resulting from excess body fat. Dr. Brian P. Lee, a hepatologist at Keck Medicine of the University of Southern California and one of the authors of the new study, aimed to determine how many people would fit this updated definition. The study used data from a nationally representative sample of 5,600 adults. It calculated excess body fat prevalence through waist and other body measurements, in addition to BMI, as recommended by the commission. The study also assessed whether participants experienced organ dysfunction or had limitations in daily physical activities.
According to the study, approximately half of U.S. adults who are considered overweight, but not obese by BMI standards, might be classified as having ‘clinical obesity.’ Published in the Annals of Internal Medicine, the study also suggested that even individuals with a normal BMI could be considered obese under the new definition.
Dr. Francesco Rubino, chair of the international Lancet Diabetes & Endocrinology Commission on obesity, appreciated the effort to determine the true prevalence of obesity. However, he expressed concerns that the study might have overestimated the number of affected individuals. He pointed out that the study included anyone with excess body fat and certain medical conditions, such as liver fibrosis, heart failure, or mobility issues, as having obesity.