On January 15, 2025, The Lancet Diabetes & Endocrinology published a major report on "Clinical Obesity Definition and Diagnostic Criteria" online. The report has been supported by 75 medical organizations around the world. The report points out that the current medical diagnosis of obesity mainly relies on body mass index (BMI), which is not a reliable indicator of personal health or disease. Relying solely on BMI to diagnose obesity may lead to misdiagnosis and have a negative impact on obese patients and society as a whole.
The report proposes a novel and sophisticated method for diagnosing obesity, that is, in addition to BMI, it is also based on other measures of excess body fat, as well as objective disease signs and symptoms at the individual level.
The report aims to address the limitations of traditional definitions and diagnoses of obesity, which hinder clinical practice and health care policies, resulting in obese patients not getting the care they need. By providing a medically unified disease diagnostic framework, the report aims to resolve the ongoing controversy over whether obesity is a disease, which is one of the most controversial and polarized debates in modern medicine.
The report provides a new model for the diagnosis of obesity.
According to the report, clinical obesity is defined as an obese state in which there are objective signs and/or symptoms of organ dysfunction directly caused by excess body fat, or a significant decrease in the ability to perform standard daily activities (such as bathing, dressing, eating and defecation). Patients diagnosed with clinical obesity should be considered to have a persistent chronic disease and receive appropriate management and treatment.
The major report established 18 diagnostic criteria for clinical obesity for adults and 13 specific diagnostic criteria for children and adolescents, including: dyspnea caused by the impact of obesity on the lungs; heart failure caused by obesity; knee or hip pain, as well as joint stiffness and limited range of motion caused by the direct impact of excess body fat on the joints; movement restrictions in children and adolescents due to certain changes in bones and joints; symptoms and signs caused by dysfunction of other organs (including kidneys, upper respiratory tract, metabolic organs, nervous system, urinary system, reproductive system and lower limb lymphatic system).
The report also proposed the concept of subclinical obesity. This refers to a state of obesity with normal organ function. Although individuals with subclinical obesity do not have persistent diseases, they may have an increased risk of developing clinical obesity and several other non-communicable diseases (NCDs) in the future, including type 2 diabetes, cardiovascular disease, certain types of cancer, and mental illness.
The report proposes that patients with clinical obesity should receive evidence-based treatment in a timely manner, with the goal of fully restoring or improving physical functions impaired by excess body fat, rather than just losing weight. Treatment and management of clinical obesity (including lifestyle interventions, drug therapy, surgical treatment, etc.) should be based on personalized risk-benefit assessments and determined through active discussions with patients.
The report points out that although people with subclinical obesity have not yet developed persistent health complications due to excess body fat, they are at high risk of future illness. Therefore, their care should be aimed at reducing risk. Depending on the individual's risk level, subclinical obese people should be provided with health counseling and long-term monitoring, or active treatment when necessary, to significantly reduce their higher risk levels.
It is estimated that more than 1 billion people are currently obese worldwide. The proposals of the major report provide an opportunity for global health systems to adopt a unified, clinically relevant definition of obesity and a more accurate method for diagnosing obesity.
