JAMA Netw Open

New obesity definition pushes U.S. prevalence near 70%

October 21, 2025

Study details: This population-based longitudinal cohort study analyzed 301,026 U.S. adults from the All of Us cohort (median age, 54; 61% female; median follow-up, 4 years) to assess the impact of a new obesity definition that combines BMI with sex- and race-specific anthropometric thresholds. Obesity was classified as either BMI-plus-anthropometric or anthropometric-only, and further stratified into clinical or preclinical obesity based on organ dysfunction or physical limitation.

Results: Obesity prevalence rose by 60% under the new definition (68.6% vs. 42.9% by BMI alone), driven by 25.9% of participants reclassified as having anthropometric-only obesity. Clinical obesity affected 36.1% of the overall cohort and increased sharply with age (54.4% in those ≥70 years). Both BMI-plus-anthropometric and anthropometric-only obesity were associated with higher odds of organ dysfunction. Clinical obesity conferred markedly increased risks of incident diabetes (adjusted hazard ratio [AHR], 6.11), cardiovascular events (AHR, 5.88), and all-cause mortality (AHR, 2.71); preclinical obesity was also associated with higher risk, but to a lesser degree.

Clinical impact: Adoption of the new definition substantially expands the population identified as obese, especially older adults, and better stratifies risk for adverse outcomes. The findings underscore the need for further research on anthropometric-only and preclinical obesity, and may prompt major changes in clinical practice and public health policy.

Source:

Fourman LT, et al. (2025, October 1). JAMA Netw Open. Implications of a New Obesity Definition Among the All of Us Cohort. https://pubmed.ncbi.nlm.nih.gov/41091468/