Daijiworld Media Network - Hyderabad

Hyderabad, Jul 22: Genetic risk factors associated with obesity in Europeans may not have the same impact on Indians, a new study from the CSIR-Centre for Cellular and Molecular Biology (CSIR-CCMB) in Hyderabad has found. Researchers say that lifestyle solutions or targeted nutrient supplementation may be more effective in managing obesity among Indians.

The study, led by Dr. Giriraj Ratan Chandak, highlights how Polygenic Risk Scores (PRS) — genetic tools used to predict the likelihood of developing obesity — are significantly more accurate in people of European ancestry than in those of South Asian origin. The difference underscores the need for population-specific models to better understand and manage obesity.

The CSIR-CCMB team analysed genomic data from individuals — both diabetic and non-diabetic — who have been tracked for nearly two decades. The long-term data helped identify obesity-related genetic variants that are more relevant to Indians, many of whom show a tendency toward abdominal obesity, a pattern distinct from that seen in Europe.

Using these variants, researchers created a PRS tailored to the Indian genome. They then built a virtual "model individual" to simulate how genetic risk interacts with lifestyle interventions like diet and exercise. Interestingly, individuals with a high genetic risk responded well to such interventions but were more prone to weight regain once those efforts ended.

“Our findings echo earlier studies on height, where European-based genetic models underestimated risk in Indian populations,” said Dr. Chandak. “Environmental and lifestyle factors appear to play a larger role in influencing obesity among Indians. This opens up new possibilities — lifestyle modifications or specific nutrient interventions tailored to an individual’s genetic background could prove especially effective.”

The findings are part of a global study that involved 600 researchers across 500 institutions, drawing on a massive dataset from the GIANT consortium and consumer DNA testing company 23andMe. The study analysed genetic data from more than 5 million individuals worldwide, including a significant South Asian representation.

The international team also developed a more advanced PRS capable of predicting obesity in adulthood from as early as age five. This test, which is twice as predictive as earlier models, could help identify children who may benefit from early preventive strategies.

“What makes this score so powerful is its ability to predict, around the age of five, whether a child is likely to develop obesity in adulthood — long before traditional risk factors emerge,” said Assistant Professor Roelof Smit from the NNF Centre for Basic Metabolic Research at the University of Copenhagen, and lead author of the study published in Nature Medicine.

The research reinforces a growing consensus: for Indians, tackling obesity may require a deeper understanding of how genetics, diet, and environment interact — and one-size-fits-all genetic models may no longer be enough.