Genetic–lifestyle link driving obesity in Indians: AIG study

Researchers at AIG Hospitals have published a multi-cohort genomic study in the international journal Scientific Reports highlighting how inherited genetic susceptibility and lifestyle factors together influence obesity risk among people of Indian ancestry.

The research was conducted in collaboration with the Luxembourg Centre for Systems Biomedicine at the University of Luxembourg and the Centre for Human Genetics, University of Marburg in Germany. The analysis used genomic and health data from Indian-origin participants in the UK Biobank along with an India-recruited cohort developed and genomically profiled at AIG Hospitals.

Speaking on the significance of the research, D Nageshwar Reddy, Chairman of AIG Hospitals, said obesity is increasingly recognised as a polygenic condition influenced by thousands of genetic variants rather than a single mutation.

However, genomic interaction data in Indian populations has been limited despite evidence that Indians often develop metabolic complications at lower body mass index (BMI) levels than Western populations.

The study analysed hundreds of thousands of genetic variants using genome-wide SNP microarray platforms to construct polygenic risk scores (PRS)—a method that estimates inherited susceptibility by aggregating the effects of multiple obesity-related genes.

Explaining the methodology, Rakesh Kalapala, Director of the Centre for Obesity & Metabolic Therapy at AIG Hospitals, said the researchers combined genomic data with lifestyle indicators such as diet, physical activity and smoking behaviour. Participants were then stratified by genetic risk and lifestyle profiles to examine how these factors interact.

The findings revealed a graded pattern of obesity risk depending on the combination of genetic susceptibility and lifestyle habits. Statistical analysis showed a significant interaction between polygenic risk and lifestyle in the larger cohort, with similar trends observed in the India-based group.

Age-stratified analysis indicated that lifestyle factors may play an especially important role in younger individuals who already carry a higher inherited risk.

Dr Reddy noted that India is experiencing a rapid rise in metabolic diseases such as insulin resistance, fatty liver disease and cardiovascular complications, often appearing earlier and at lower BMI thresholds.

He added that understanding how inherited risk interacts with lifestyle exposures can help develop more targeted prevention strategies rather than one-size-fits-all approaches.

Researchers said the study provides important insights into the biological and environmental factors shaping obesity risk in Indians.

The findings also suggest that individuals with similar body weight may experience very different metabolic outcomes depending on their genetic background and lifestyle patterns.

While the study acknowledged limitations such as self-reported lifestyle data and the need to expand the India-based cohort, it strengthens evidence for gene–environment interaction research in Indian populations and highlights the growing role of genomic risk modelling in preventive medicine.

With India facing one of the fastest-growing burdens of obesity-related diseases globally, the research may help guide early screening, risk stratification and targeted prevention strategies in the future.