Broader Obesity Criteria Reveal Hidden Health Risks in US Adults

A revised definition of obesity that goes beyond body mass index (BMI) suggests that nearly 70% of American adults may now fall into the obesity category, according to a study published in JAMA Network Open. Researchers from Mass General Brigham analyzed health data from over 300,000 participants in the National Institutes of Health’s All of Us Research Program and found a sharp rise from the previous estimate of about 40% based on BMI alone.

The updated framework incorporates additional body measurements such as waist circumference and waist-to-height ratio, which better reflect harmful fat distribution, particularly abdominal fat. Under this approach, individuals with normal BMI but elevated waist-related measures are also classified as having obesity.

Notably, older adults were most affected, with nearly 80% of those over 70 meeting the new criteria. Importantly, individuals newly identified under this definition showed higher rates of diabetes, cardiovascular disease, and mortality. The findings highlight the need for more precise obesity screening and targeted treatment strategies that focus on body composition rather than weight alone.

05-01-2026