A global Commission published in The Lancet Diabetes & Endocrinology, endorsed by over 75 medical organisations worldwide, proposes a groundbreaking approach to diagnosing obesity. This model integrates measures of excess body fat with objective signs and symptoms of individual ill health, moving beyond the traditional reliance on body mass index (BMI).
This proposal addresses the shortcomings of the current obesity definition and diagnosis, which often impede effective clinical practice and healthcare policies, leaving many individuals without necessary care. By establishing a medically coherent framework for diagnosing obesity, the Commission seeks to resolve the contentious debate over whether obesity should universally be classified as a disease.
As per the Commission, framing obesity as either always a disease or never a disease oversimplifies the issue. Evidence shows a more nuanced reality—some individuals with obesity maintain normal health, while others exhibit severe illness. Viewing obesity solely as a risk factor can deny timely care to those suffering from obesity-induced ill health. On the other hand, classifying obesity as a disease risks overdiagnosis, unnecessary treatments, and substantial societal costs.
This framework accounts for these complexities, advocating personalised care, timely treatment for clinical obesity, and risk-reduction strategies for pre-clinical obesity. It ensures fair resource allocation and medically meaningful prioritisation of treatment.
With over one billion people globally affected by obesity, the Commission offers health systems a universally applicable, clinically relevant definition and a more accurate diagnostic method.
Current diagnostic criteria for obesity, based primarily on BMI, often lead to misclassification and misdiagnosis. While useful for identifying health risks, BMI does not measure body fat directly, assess its distribution, or reflect individual health.
Excess fat around organs, such as the liver or heart, poses higher health risks than subcutaneous fat. Yet, BMI alone cannot account for these variations. People with high BMI may not have ongoing illness, while others with normal BMI but high organ fat may face significant health issues.
The Commission advocates moving beyond BMI to diagnose obesity by incorporating additional body size measurements (e.g., waist circumference or waist-to-height ratio), direct body fat assessments (e.g., via DEXA scans) and pragmatic assumptions of excess body fat in cases of very high BMI (>40 kg/m²).
The Commission also introduces two new categories of obesity:
- Clinical Obesity: Characterised by excess body fat impairing organ function or daily activities. Patients with clinical obesity should receive management and treatment similar to other chronic diseases. Diagnostic criteria include conditions like breathlessness, joint pain, or heart failure directly linked to obesity.
- Pre-Clinical Obesity: Defined as obesity without current organ dysfunction. Although individuals face increased risk for future illnesses like diabetes or cardiovascular disease, their care should focus on risk reduction rather than treatment for active disease.
The framework promotes tailored approaches to prevention and treatment, ensuring that care is proportional to individual needs. For clinical obesity, treatment options may include lifestyle changes, medications, or surgery, informed by risk-benefit assessments. Pre-clinical obesity management emphasises monitoring and preventive strategies.
The Commission also highlights the importance of combating weight stigma. The way obesity is discussed often perpetuates stigma, hindering effective care. This approach seeks to reduce misconceptions and advocate for better training among healthcare providers and policymakers.
Source: The Lancet Diabetes & Endocrinology
Image Credit: iStock
