Introduction

Obesity has become a major public health crisis worldwide, with India witnessing a sharp rise in cases. Traditionally, Body Mass Index (BMI) has been the primary tool for diagnosing obesity. However, growing research suggests BMI alone is inadequate in assessing body fat distribution and metabolic health.

• Recognizing these limitations, The Lancet Diabetes & Endocrinology Commission has introduced a broader definition of obesity, incorporating multiple physical and metabolic parameters. This comes at a time when new medical interventions, such as GLP-1 receptor agonists like Ozempic, are offering more effective treatment options for clinical obesity.

Limitations of BMI as a Diagnostic Tool

BMI has long been the standard for diagnosing obesity. Under this system:

• BMI <18.5 – Underweight
• BMI 18.5–24.9 – Normal
• BMI 25–29.9 – Overweight
• BMI ≥30 – Obese

However, this method often results in both over-diagnosis and under-diagnosis. Some individuals with high muscle mass may have a BMI above 30 while being metabolically healthy, whereas others with lower BMI may still have excessive fat leading to obesity-related complications.

This issue is particularly relevant in India, where many individuals with BMI below 30 still carry excess abdominal fat, significantly increasing their risk of diabetes, hypertension, and cardiovascular diseases. In recognition of these differences, India revised its BMI cut-offs in 2009, lowering the obesity threshold to 25. However, even this adjustment failed to fully address the issue, leading to the need for a more comprehensive framework.

The Lancet Commission’s New Definition of Obesity

The Lancet Commission now defines clinical obesity as a chronic illness that alters organ function, regardless of BMI or co-existing conditions. This new framework incorporates multiple physical and metabolic parameters, including:

• BMI
• Waist circumference
• Waist-to-hip ratio
• Waist-to-height ratio
• Muscle mass and fat distribution
• Organ function and metabolic health

Unlike the previous BMI-based self-diagnosis, obesity must now be determined by a physician after evaluating a range of symptoms, including:

• Breathlessness and sleep apnea
• High triglyceride levels and metabolic dysfunction
• Non-alcoholic fatty liver disease
• Chronic fatigue and joint pain

Introducing Pre-Clinical Obesity

One of the major changes in the new definition is the elimination of the "overweight" category, replacing it with pre-clinical obesity. This category includes individuals with excess body fat but no metabolic dysfunction or organ impairment.

For some, pre-clinical obesity may progress to clinical obesity, while others may remain metabolically healthy. This distinction is crucial for early intervention, emphasizing prevention rather than treatment through lifestyle modifications, dietary improvements, and regular monitoring.

India’s Modified Obesity Guidelines

India has adapted the Lancet Commission’s recommendations to suit its population’s specific needs. The classification now includes:

• Stage 1 Obesity – BMI above 23, with or without metabolic dysfunction
• Stage 2 Obesity – BMI above 23, with additional obesity-related health complications

While BMI remains the entry point for diagnosis in India due to its familiarity, physicians are now required to assess additional factors such as waist circumference and waist-to-height ratio before confirming an obesity diagnosis.

Obesity in India: A Growing Public Health Concern

The NFHS-5 (2019–21) data shows that nearly one in four Indian adults is obese, with the prevalence rising rapidly. The World Obesity Federation reports that India has one of the steepest annual increases in childhood obesity, with rates doubling in the last 15 years and tripling over three decades.

Multiple factors contribute to this crisis:

• Nutritional Challenges: The State of Food Security and Nutrition in the World (2024) reports that 55% of Indians cannot afford a healthy diet, and 40% lack adequate nutrient intake.
• Unhealthy Diets: Increased consumption of high-fat, high-sugar, and ultra-processed foods (HFSS & UPF) is a major contributor.
• Sedentary Lifestyle: A WHO report states that 50% of Indians fail to meet recommended physical activity levels.
• Genetic Predisposition: The Thin-Fat Indian Hypothesis suggests that many Indians have high body fat percentages despite normal BMI, increasing their risk of diabetes and cardiovascular diseases.
• Rising Disease Burden: One in four Indian adults is either diabetic or prediabetic, with obesity being a major contributing factor.

The Economic Impact of Obesity

Obesity is not just a health issue; it has significant economic consequences.

• In 2019, obesity-related healthcare costs in India were estimated at $28.95 billion (1.02% of GDP).
• By 2030, this burden is expected to rise to ₹4,700 per capita (1.57% of GDP) if no interventions are made.

The economic impact stems from rising healthcare expenses, lost productivity, and the increasing prevalence of obesity-related diseases.

Approaches to Address Obesity in India

A multi-pronged strategy is essential to tackle India’s obesity crisis.

1.   Public Awareness & Education:

o    Recognizing obesity as a chronic disease, not just a personal issue.

o    Awareness campaigns to highlight its link to diabetes, hypertension, and heart disease.

2.   Promoting Physical Activity:

o    Developing bicycle lanes, parks, and open gyms to encourage exercise.

o    Workplace wellness programs promoting regular physical activity.

3.   Regulating Unhealthy Foods:

o    Higher taxation on HFSS and UPF foods.

o    Subsidies for healthier food options like fruits and vegetables.

o    Ethical marketing practices in the food industry.

4.   Routine Health Monitoring & Preventive Care:

o    Regular check-ups measuring BMI, waist circumference, and body fat percentage.

o    Educating individuals about optimal weight and waist circumference.

5.   Medical Interventions:

o    Clear guidelines for responsible use of anti-obesity medications.

o    Weight loss surgeries for severe cases under strict medical supervision.

6.   School-Based Interventions:

o    Promoting healthy diets and exercise in schools.

o    Regulating canteen food options to ensure balanced nutrition.

7.   Inter-Ministerial Coordination:

o    Collaboration between health, finance, education, agriculture, and urban planning ministries.

o    Launching a “Suposhan Abhiyan” to replace traditional nutrition programs.

8.   Research & Evidence-Based Policies:

o    More epidemiological studies on obesity trends.

o    Training healthcare providers in obesity prevention and management.

9.   Corporate & Industry Responsibility:

o    Encouraging online food delivery platforms to promote healthier options.

o    Utilizing CSR funds for obesity awareness initiatives.

Conclusion

Obesity in India is a rapidly escalating public health and economic crisis. The Lancet Commission’s redefinition of obesity marks a significant shift in understanding and managing the condition. India’s modified guidelines provide a more scientific yet practical approach, ensuring effective diagnosis and intervention.

However, addressing obesity requires more than medical treatment—it demands a comprehensive strategy integrating public health policies, urban planning, education, and corporate responsibility. Without decisive action, the burden of obesity will continue to rise, affecting millions and straining healthcare resources. A holistic approach, combining prevention, treatment, and policy reform, is essential to control this growing epidemic and secure a healthier future for India.