Diagnosis and Management of Obesity: A Synthesis of Contemporary Guidelines

Obesity is a chronic, adiposity-based disease with increasing global prevalence and multiple, competing definitions. Traditionally, body mass index (BMI) has been the primary tool for diagnosis, although it does not completely reflect adipose tissue mass, distribution or associated organ dysfunction. In the past 2 years, major professional societies, including the European Association for the Study of Obesity (EASO), the Lancet Diabetes & Endocrinology Commission, the American College of Cardiology (ACC), and the American Association of Clinical Endocrinologists (AACE), have advanced new diagnostic frameworks that move beyond BMI to incorporate multimodal assessment of adiposity and its clinical consequences. By integrating anthropometric precision with standardized complication assessment, these frameworks support earlier identification of risk, improved prognostication, and more equitable, patient-centred obesity care. However, the way in which the new guidelines should be integrated into routine clinical care remains unclear. This paper synthesizes current evidence across anthropometric measures of obesity and body composition imaging, clarifying the diagnostic performance, limitations, and relevance of these measures across diverse populations. The authors compare areas of convergence and divergence among the new guidelines, particularly the shift towards defining clinical obesity on the basis of both excess adiposity and evidence of organ dysfunction or functional impairment.