The international Commission on Clinical Obesity is proposing a major revision of the diagnosis of obesity. The new approach goes beyond body mass index (BMI) and includes additional measurements of body fat as well as objective symptoms at the individual level. Researchers from the German Center for Diabetes Research (DZD) also participated in the Commission. The findings will be presented for the first time during an event held by ‘The Lancet Diabetes & Endocrinology’ in London on January 16 and will be published in a future article in the journal.

There are around a billion people worldwide with obesity. In Germany, one in four adults is severely overweight. Many suffer from the disease and the costs for treating obesity and its complications, such as type 2 diabetes, cardiovascular disease, arthrosis, certain cancers, and mental disorders, put a strain on health systems. A more precise diagnosis could help people in a more targeted manner and reduce costs.

Currently, medical approaches to diagnosing obesity are primarily based on body mass index (BMI). However, BMI is not a reliable measure of health or disease at the individual level. This can lead to misdiagnoses and negative consequences for affected individuals and society. The Commission on Clinical Obesity therefore recommends also using measurements of waist circumference or direct fat measurements in addition to BMI to detect obesity in order to reduce the risk of misclassification.

Two diagnostic categories: Clinical and Preclinical Obesity

In addition, the Commission is proposing two new diagnostic categories: “clinical obesity” and “preclinical obesity.” Clinical obesity is defined as a chronic disease that is associated with persistent organ dysfunction due to severe overweight. Preclinical obesity, by contrast, is associated with an increased health risk but is not considered a chronic disease.

Personalized health advice and evidence-based care

The Commission advocates that all people with obesity receive personalized health advice and evidence-based care—free from stigmatization and blame. This should be achieved through different strategies for clinical and preclinical obesity.  “Only considering obesity as a risk factor and never as a disease can lead to people who experience health issues solely as a result of obesity being unjustly denied access to time-critical care. On the other hand, a blanket definition of obesity as a disease can lead to overdiagnosis and the unwarranted use of medication and surgical interventions with potential harm to the individual and staggering costs for society,” says the Chair of the Commission, Professor Francesco Rubino of King’s College London.

© Matthias Popp

"A comprehensive and balanced definition of obesity is long overdue to address the medical and socioeconomic challenges,” stresses Prof. Stefan Bornstein, member of the Commission and Director of the Department of Internal Medicine of the University Clinic Carl Gustav Carus Dresden as well as scientist at the German Center for Diabetes Research (DZD). The Commission’s proposal gives health systems an opportunity to adopt a clinically relevant definition of obesity and more precise methods for its diagnosis. This can contribute to a more efficient use of resources and better targeted help for individuals.

Commission on Clinical Obesity

Chaired by Prof. Francesco Rubino of King’s College London, the Commission comprises 56 international experts from a wide range of medical disciplines, including endocrinology, internal medicine, surgery, biology, nutrition and public health, representing numerous countries and different health systems. Endorsed by the World Obesity Federation and 75 other medical organizations around the world, the Commission sets out a new evidence-based definition of clinical obesity, which is understood as a chronic systemic disease caused by excessive obesity. The goal is to address limitations in the traditional definition and diagnosis and ensure that affected individuals receive the care they need. The Commission also involved people with obesity and, in particular, dealt with the possible impacts of the new definitions of obesity on widespread social stigmatization.

The Commission will present its recommendations on the definition and diagnostic criteria of clinical obesity for the first time during a launch event held by The Lancet Diabetes & Endocrinology on January 16, 2025 from 1 to 5 pm (GMT).
Members of the Commission will discuss the effects on practice and policy with invited experts and other interest groups in London (UK) and various locations around the world. The event will be live-streamed.
The Lancet Diabetes & Endocrinology Commission Launch Event | World Obesity Federation

Further information:
Link to the publication: https://www.thelancet.com/commissions/clinical-obesity
Link to the press release from The Lancet Diabetes & Endocrinology

Scientific Contact:
Prof. Stefan Bornstein
Member of the Commission on Clinical Obesity and speaker at the launch event for the recommendations on the definition and diagnostic criteria for clinical obesity
Director of the Center for Internal Medicine at the University Hospital Carl Gustav Carus Dresden
Group leader at the DZD partner Paul Langerhans Institute Dresden of Helmholtz Munich at the University Hospital and the Medical Faculty Carl Gustav Carus of TU Dresden