A New Definition of Obesity for Adults
Feb 24, 2025There’s a new sheriff in town, and BMI is out! Almost…
The Lancet Diabetes and Endocrinology Commission on Obesity recently published its report defining obesity by excess adiposity rather than solely relying on BMI (Rubino, 2025). Whereas obesity has traditionally been defined as a BMI of 30 or higher, the new definition uses BMI as an initial screening tool. In those with a BMI of 30 or above, excess adiposity needs to be confirmed using an anthropometric measure such as waist circumference or by a body composition test. In those where excess adiposity has been confirmed, the next step is to determine if there is any obesity-related organ dysfunction, any age-appropriate limitations of daily activities, or both. Those with either or both of these (plus confirmation of excess adiposity) are defined as having “clinical obesity”. Those with excess adiposity but no organ dysfunction and/or limitations of daily activity are defined as having “pre-clinical obesity”. The current categories of Overweight, Class I, II and II Obesity are no longer recommended.
This change helps to reduce the limitations of using BMI alone and will exclude from the definition of clinical obesity those with a high BMI but no excess adiposity (ie athletes). The distinction between pre-clinical versus clinical obesity is more in line with how other medical conditions are diagnosed. Those with pre-clinical obesity will receive education and their condition monitored over time. Those with clinical obesity will receive evidenced based treatments for their condition.
This is the first major change to the definition of obesity since the WHO adopted a BMI based definition in 1997. As such, the implementation of the new definition will take an immense effort where physicians will need to be educated on how to select the best method to determine excess adiposity and how to successfully standardize these measurements in practice. The public will also need to be educated. GHBCI is here to support these educational efforts! Our first workshop on this topic will be a collaboration with Canyon Ranch Health and Wellness Resort in Tucson, AZ. Any health care practitioner is welcome to attend!
Rubino F, Cummings DE, Eckel RH et al. Definition and diagnostic criteria of clinical obesity. Lancet Diabetes Endocrinol 2025; Published Online January 14, 2025. https://doi.org/10.1016/S2213-8587(24)00316-4.
