
Obesity is a global health challenge, with over 1 billion people estimated to live with the condition. However, the current method for diagnosing obesity, which heavily relies on Body Mass Index (BMI), has raised significant concerns among medical experts worldwide. Recent findings by the Lancet Commission have led to calls for a transformative shift in diagnosing obesity, focusing on more comprehensive and accurate measures.
Why BMI Alone Is Insufficient
BMI, a calculation based on height and weight, has been the standard tool for diagnosing obesity for decades. While it provides a simple method for assessing body fat levels, it has several limitations:
Not a Direct Measure of Fat: BMI doesn’t account for fat distribution or differentiate between muscle and fat.
Over-Diagnosis and Under-Diagnosis: Individuals with high BMI may have normal organ functions and overall health, while those with excess body fat but normal BMI could have undiagnosed health risks.
Lack of Health Indicators: BMI doesn’t provide information on symptoms or the functional impact of obesity on health.
These shortcomings highlight the need for a more nuanced approach to obesity diagnosis and management.
The Lancet Commission’s Recommendations
A report published in The Lancet Diabetes and Endocrinology journal, endorsed by over 75 medical organisations, proposes a “reframing” of obesity diagnosis. Key recommendations include:
Introducing New Diagnostic Measures
Waist-to-Hip Ratio and Waist-to-Height Ratio: These provide a better understanding of fat distribution and associated health risks.
Signs and Symptoms of Ill Health: Objective indicators of reduced organ function or impaired daily activities due to excess body fat should be included.
Categorising Obesity
Clinical Obesity:
Defined by the presence of symptoms such as reduced organ function or difficulty performing daily tasks (e.g., bathing, dressing, eating).
Considered a chronic disease requiring management with treatments like weight-loss drugs or surgery.
Pre-Clinical Obesity:
Characterised by normal organ function but increased risk of future health issues like type 2 diabetes, cardiovascular disease, and mental illness.
Requires preventive measures to mitigate risks.
The Benefits of Reframing Obesity
Prof Francesco Rubino, chair of the Lancet Commission and an expert in metabolic and bariatric surgery at King’s College London, emphasised the need for a universal and clinically relevant definition of obesity. He stated:
“Reframing obesity allows for personalised care, acknowledging the diverse ways obesity impacts individuals’ health. A more precise approach prevents overdiagnosis and ensures timely intervention for those in need.”
Expert Reactions
The medical community has largely welcomed the report:
Royal College of Physicians:
Dr Kath McCullough highlighted the limitations of BMI, praising the proposed distinction between clinical and pre-clinical obesity as a step towards early intervention and better care.
Obesity Health Alliance:
Katharine Jenner stressed the importance of supporting individuals with excess weight and called for a focus beyond measurement methods.
Implications for Global Health
A redefined approach to diagnosing obesity could have profound implications:
Better Resource Allocation: Targeted care for those with clinical obesity can reduce unnecessary treatments and associated societal costs.
Improved Patient Outcomes: Early identification of risks allows for preventive interventions, reducing the likelihood of severe health complications.
Enhanced Awareness: A nuanced understanding of obesity encourages a more empathetic and tailored approach to care.
Moving Forward
The Lancet Commission’s findings challenge the longstanding reliance on BMI as the sole measure of obesity. By adopting more comprehensive diagnostic tools and reframing obesity into clinical and pre-clinical categories, healthcare systems can provide more effective and personalised care.
Addressing obesity requires a multifaceted approach that not only focuses on accurate diagnosis but also prioritises support for individuals at every stage of their health journey. This shift represents a significant step towards tackling one of the most pressing global health challenges of our time.
References:
Lancet Diabetes and Endocrinology Journal
Statements from Prof Francesco Rubino and Dr Kath McCullough
Insights from the Obesity Health Alliance