Obesity Risk in Indians: AIG Hospitals Study Highlights Genes and Lifestyle Factors

India's Mounting Obesity Challenge

Obesity has emerged as a pressing public health issue in India, with prevalence rates surging across urban and rural populations alike. According to the National Family Health Survey-5 (NFHS-5, conducted 2019-2021), approximately 24 percent of women and 23 percent of men are classified as overweight or obese, marking a sharp rise from previous decades.3637 Urban areas show higher rates, often exceeding 30-40 percent, driven by sedentary lifestyles, while rural regions are catching up rapidly due to changing dietary patterns and reduced physical labor. Abdominal obesity, a particularly dangerous form characterized by excess fat around the waist, affects nearly 40 percent of women and 12 percent of men, heightening risks for metabolic disorders even at seemingly normal body mass index (BMI) levels.38

This trend is alarming given Indians' unique 'metabolic sensitivity'—a phenomenon where individuals develop insulin resistance, fatty liver disease, and cardiovascular complications at lower BMI thresholds compared to Western populations. The Economic Survey 2025-26 highlights obesity as fueling non-communicable diseases (NCDs) like diabetes and heart disease, projecting massive economic burdens, with global costs potentially reaching trillions by 2060.9091 In India alone, obesity-related expenses could climb exponentially, straining healthcare systems and productivity.

The AIG Hospitals Study: A Genomic Breakthrough

A groundbreaking multi-cohort study led by researchers at AIG Hospitals in Hyderabad, published in Scientific Reports on December 8, 2025, sheds light on obesity risk in Indians by examining the interplay between genetics and lifestyle.59 Collaborating with institutions like the University of Luxembourg and University of Marburg, the team analyzed data from 6,663 Indian-ancestry participants in the UK Biobank and 91 individuals from the Wellytics-Asian Institute of Gastroenterology (W-AIG) cohort genomically profiled at AIG Hospitals.

The study quantified genetic predisposition using a polygenic risk score (PRS) for BMI, derived from thousands of single nucleotide polymorphisms (SNPs) associated with obesity from the Polygenic Score Catalog. Lifestyle was assessed via a composite score incorporating three modifiable factors: smoking status, physical activity levels, and dietary habits, dichotomized into favorable (at least two healthy behaviors) or unfavorable.111 Key authors from AIG Hospitals, including Dr. Rakesh Kalapala and Dr. D. Nageshwar Reddy, emphasized that while obesity is polygenic—influenced by numerous variants—lifestyle choices can significantly modulate this risk.58

Decoding Polygenic Risk Scores in Obesity

A polygenic risk score (PRS), also known as a polygenic risk score (PRS), aggregates the effects of multiple genetic variants to predict disease susceptibility. In this context, the BMI-PRS sums weighted effects from SNPs linked to body mass index, adjusted for population ancestry using principal components analysis. Obese participants showed markedly higher PRS values (UK Biobank: P = 1.3 × 10⁻⁸⁵; W-AIG: P = 6.67 × 10⁻⁴).59

While specific genes like FTO (fat mass and obesity-associated gene, rs9939609 variant) and MC4R (melanocortin 4 receptor gene, rs17782313 near-variant) have shown associations in prior Indian studies—increasing obesity odds by 1.15-1.3 times—the PRS captures broader heritability, explaining 18-20 percent of risk in South Asians per recent CCMB research.7051 Indians exhibit distinct variant frequencies, amplifying central obesity tendencies.

Lifestyle Components: Smoking, Activity, and Diet

The study defined favorable lifestyle precisely: non-smoking or minimal (<2 cigarettes/day); physical activity (≥5 days/week of moderate/vigorous exercise); and healthy diet (meeting ≥4/6 criteria: 1-3 servings/week fruits/vegetables/fish/whole grains, ≤1 refined grains/meat). Unfavorable profiles correlated strongly with obesity when paired with high PRS.111

• Smoking cessation reduces caloric intake dysregulation and metabolic inflammation.
• Physical activity builds muscle, counters sarcopenia, especially pre-50.
• Diet emphasizes balanced Indian staples—millets, veggies—over ultra-processed foods surging in consumption.

In India's context, urbanization promotes desk jobs and junk food, exacerbating risks. For more on health research careers, check research jobs in India.

Gene-Lifestyle Synergy: Quantified Risks

Data adapted from study; high-risk unfavorable group faces 3x odds. W-AIG showed even starker OR=24.51, underscoring interaction.59 "Genes load the gun, lifestyle pulls the trigger," notes Dr. Reddy.58

Photo by ARTO SURAJ on Unsplash

Age Window: Critical Interventions Before 50

Age-stratified analysis revealed lifestyle's outsized impact under 50, when muscle-building and fat metabolism are optimal. Post-60, hormonal shifts hinder reversal. Dr. Kalapala urges early screening: waist circumference (>90cm men, >80cm women), blood markers like HbA1c. Start with 25min aerobic + strength training weekly.56

India-Specific Metabolic Risks

Indians' 'thin-fat' phenotype—low BMI, high visceral fat—drives NCDs. Obesity fuels diabetes (projected 134 million cases by 2045) and CVD, costing billions. Explore genomic studies at Indian universities via India higher ed jobs.90

Prevention: Practical Steps Tailored for Indians

• Diet: Prioritize millets, lentils, veggies; limit rice/sweets.
• Activity: Brisk walking 150min/week + yoga.
• Screening: Annual BMI/waist checks, genetic PRS if high-risk family.
• Policy: Front-of-pack labeling, school programs.

Culturally adapted interventions show 5-10% weight loss. For careers in public health research, see academic CV tips.

Economic Toll and Future Projections

Obesity could cost India USD 28.95 billion in 2019 terms, escalating with 351 million at-risk adults. Links to diabetes (USD 11.4 trillion cumulative) demand national strategy.97

Advances in Indian Genomics Research

Universities like CCMB, IITs lead PRS development for South Asians. Opportunities abound in postdoc positions.

Photo by Sandeep Kashyap on Unsplash

Outlook: Personalized Medicine Horizon

Integrating PRS with lifestyle apps promises precision prevention. Explore rate my professor for top researchers, higher ed jobs, career advice.