A diagnosis of obesity should go beyond an assessment based solely on Body Mass Index (BMI), as excess weight does not automatically mean that a person is already suffering from conditions associated with this state. A study published in the journal Nature, which analyzed data from over 844,000 adults in China, the United Kingdom, the United States, and Spain, shows that approximately 27% of individuals with obesity present with the clinical form of the condition, characterized by organ dysfunction. The research advocates for a revision of diagnostic criteria, distinguishing between „preclinical” obesity-where excess fat acts as a risk factor-and „clinical” obesity, where associated health problems are already present. These findings align with a proposal put forward in 2025 by an international commission of experts, which recommends a more comprehensive assessment than simply relating weight to height.
• Body Mass Index does not provide a complete picture
The study published in Nature, titled „Validation of clinical and preclinical obesity across global cohorts,” analyzed data from 844,108 adults drawn from four major medical and research databases. The authors compared the traditional classification of obesity-based on BMI-with a system that also incorporates waist circumference, the waist-to-height ratio, and the identification of organ dysfunction. According to researchers, relying exclusively on BMI can lead to both the overestimation and underestimation of the number of individuals with obesity. Depending on the population analyzed, between 1.2% and 3.1% of participants were classified as obese based on BMI, even though additional measurements did not confirm a corresponding level of adiposity. Conversely, between 5.2% and 8.6% of participants had body fat levels consistent with obesity, yet were not identified as such based on criteria relying solely on BMI. When additional measurements were incorporated, the prevalence of obesity increased across all…
