A large international study reports that a new clinical definition of obesity performs better than body mass index (BMI) for identifying people at different health risk, including differences in mortality risk. The work, published in Nature, tests an approach that incorporates measurements such as waist circumference and distinguishes clinical obesity from “preclinical” stages based on obesity-related organ dysfunction.
Across the outlets, the central emphasis is on improving diagnosis and risk stratification beyond BMI alone. Nature describes a proposed framework—originating in a 2025 proposal—that uses waist-related measures and obesity-induced organ dysfunction to classify obesity more clinically. Another Nature report focuses on validating that diagnostic scheme across global cohorts, describing it as more useful than BMI-based classification. Medical Xpress highlights the overall finding that the new definition outperforms BMI in diagnosing obesity and in assessing prognosis, including mortality risk.
