The redefinition and classification of obesity introduced by the Lancet Diabetes & Endocrinology Commission marks a groundbreaking shift in how this complex condition is understood and addressed. Moving beyond the traditional reliance on Body Mass Index (BMI), this new framework highlights obesity as a chronic, systemic disease while offering a nuanced, clinically relevant perspective. As a dietitian and mentee of Dr Anoop Misra, one of the esteemed co-authors of this landmark work, I am proud to see his pivotal role in reshaping global health conversations on obesity.
The Classification Model: Precision in Diagnosis
Central to the new framework is the classification model of obesity, which provides a much-needed distinction between preclinical obesity and clinical obesity:
- Preclinical obesity refers to excess adiposity without impairments in organ or tissue function. While individuals in this category may appear healthy, they face a heightened risk of developing obesity-related diseases over time.
- Clinical obesity is defined as excess adiposity that leads to functional impairments or organ damage, such as heart disease, type 2 diabetes etc. Along with limitations in day-to-day life activities.Â
This two-stage model enhances diagnostic precision, guiding clinicians in early identification and personalised treatment strategies. It ensures that care focuses not just on the presence of excess fat but also on its impact on health and daily functioning.
Image reference: Definition and diagnostic criteria of clinical obesity
BMI’s Evolving Role
For years, BMI has been the go-to measure for defining obesity. However, its limitations are glaring. BMI cannot differentiate between muscle and fat, nor does it account for fat distribution or its impact on health. This often leads to the overdiagnosis of some individuals while overlooking others who face significant health risks due to excess adiposity.
While the model recognises BMI’s utility as a screening tool at the population level, it emphasises the need for additional measures to confirm excess adiposity at an individual level. Anthropometric criteria such as waist circumference, waist-to-hip ratio, or direct fat measurements (like DEXA scans) must complement BMI to provide a more accurate assessment of health risks. This dual approach balances BMI’s simplicity with a more comprehensive evaluation of an individual’s healtim
Image reference: Rubina, F et al. Definition and diagnostic criteria of clinical obesity. The Lancet Diabetes & Endocrinology.
Destigmatising Obesity
One of the most powerful aspects of this redefinition is its potential to reduce stigma. Obesity is now recognised as a complex, multifactorial condition influenced by genetic, metabolic, environmental, and psychological factors—not merely the result of lifestyle choices. This shift reframes obesity as a chronic illness that deserves empathy, understanding, and equitable access to healthcare.
By rejecting weight-centric biases and advocating for health-first approaches, this new framework emphasises dignity and respect for individuals living with obesity. The inclusion of voices of those with lived experience in developing this classification underscores the importance of a patient-centred approach to healthcare.
Image reference: Rubina, F et al. Definition and diagnostic criteria of clinical obesity. The Lancet Diabetes & Endocrinology.
Image reference: Rubina, F et al. Definition and diagnostic criteria of clinical obesity. The Lancet Diabetes & Endocrinology.
Implications for Australia
In the Australian context, where obesity rates remain alarmingly high, the new classification provides an opportunity to address the unique needs of diverse populations. Ethnic-specific BMI thresholds and culturally appropriate interventions are now critical components of obesity care, ensuring equitable healthcare delivery across various communities.
This redefinition places responsibility on policymakers and healthcare systems to provide evidence-based interventions, tackle weight-based stigma, and shift public health campaigns from simplistic weight-loss messaging to a more nuanced discussion of health and wellbeing. Public health initiatives must embrace this new understanding of obesity by investing in preventative strategies, increasing access to treatments, and ensuring healthcare professionals receive training to deliver compassionate care.
The New Indian Obesity Diagnosis Classification
This new classification model also considers the unique metabolic characteristics of different populations. For India, the Indian Obesity Diagnosis Classification has been adapted to reflect the distinct health risks associated with excess adiposity in the Indian population. Research shows that Asian Indians are more susceptible to obesity-related diseases, such as type 2 diabetes, at lower BMI thresholds compared to other ethnic groups.
The new classification system addresses concerns with traditional BMI-based measures by introducing a more detailed and functional approach:
- Focus on Adiposity and Functionality: Rather than relying solely on BMI cut-offs, the system evaluates adiposity levels and their functional impacts.
- Two-Stage Framework:
- Stage 1 Obesity: Increased BMI (>23 kg/m2) along with adiposity without functional limitations or organ dysfunction.
- Stage 2 Obesity: Increased BMI (>23 kg/m2) along with heightened adiposity with impaired physical or organ functions and/or obesity-related comorbidities.
- Key Emphasis: This framework prioritises health risks and quality of life, shifting the focus from weight-centric metrics to a more comprehensive understanding of obesity’s impacts.
Broadening the Perspective on Obesity
This new framework addresses several critical aspects of obesity that were often overlooked:
- It recognises obesity’s impact on mental health and the emotional toll of societal stigma.
- It aligns with the broader definition of chronic diseases by focusing on the progressive and systemic nature of obesity-related complications.
- It highlights the importance of early intervention in preclinical obesity to prevent the development of life-altering conditions.
Conclusion
The revised definition and classification of obesity signal a significant turning point in global health. By refining BMI’s role, introducing a two-stage diagnostic model, and addressing the multifactorial nature of obesity, this framework lays the foundation for more precise, compassionate, and effective care. As we embrace this change, we can look forward to a future where individuals living with obesity receive the respect, understanding, and evidence-based treatment they deserve.
References:
- Dr. Anoop Misra: https://search.app/1RaeCCCjSSafKrnv5 , LinkedIn: https://in.linkedin.com/in/anoop-misra-323b0656Â
- Rubino, F., Cummings, D. E., Eckel, R. H., Cohen, R. V., Wilding, J. P., Brown, W. A., … & Mingrone, G. (2025). Definition and diagnostic criteria of clinical obesity. The Lancet Diabetes & Endocrinology.
- Misra, A., Vikram, N. K., Ghosh, A., Ranjan, P., Gulati, S., & Members, I. O. C. (2025). Revised definition of obesity in Asian Indians living in India. Diabetes & Metabolic Syndrome: Clinical Research & Reviews, 102989.Â