WASHINGTON - A newly broadened definition of obesity reveals nearly 70% of American adults now qualify as having the condition, according to research published October 16, 2023, in the journal Obesity. The findings, based on data from 2015-2020, underscore a significant public health challenge and prompt a reevaluation of how the nation addresses weight-related health risks.
For decades,obesity has been defined using a Body Mass Index (BMI) of 30 or higher. However, the updated criteria, developed by the American Heart Association, considers a BMI of 25 or greater as obesity, acknowledging the increased health risks associated with lower BMI levels than previously recognized. this shift impacts prevalence rates dramatically, revealing that 69.4% of U.S.adults-approximately 183 million people-are now classified as obese.
The revised definition stems from mounting evidence demonstrating that health risks traditionally linked to obesity, such as heart disease, stroke, type 2 diabetes, and certain cancers, begin to increase at a lower BMI threshold. “We’re recognizing that the risks associated with excess weight start at a lower BMI than we previously thought,” explained dr. Fatima Cody Stanford, an obesity medicine physician and researcher at Massachusetts General Hospital, and lead author of the study. “This isn’t about stigmatizing weight; it’s about recognizing the physiological impact of weight on health.”
The study analyzed data from the National Health and Nutrition Examination Survey (NHANES) involving over 16,000 adults. Using the new criteria, researchers found that 49.3% of adults were classified as having Class I obesity (BMI 25-29.9), 29.7% as Class II obesity (BMI 30-34.9), and 10.4% as Class III obesity (BMI 35 or higher).
the change in definition is expected to influence clinical guidelines, public health initiatives, and research priorities. Experts anticipate a greater focus on early intervention and preventative measures to address weight-related health issues across a wider segment of the population. The American Heart Association hopes the updated classification will encourage more individuals to seek support and treatment, ultimately reducing the burden of obesity-related diseases.