New research highlights unique risks for South Asian men when gaining weight

Gaining even a small amount of weight could significantly impact the metabolic health of young South Asian men, according to a recent study led by the University of Glasgow and published in Nature Metabolism.

The findings suggest that South Asian men may face greater risks of developing type 2 diabetes compared to their white European counterparts, even with modest weight gain.

The research, part of the GlasVEGAS (Glasgow visceral and ectopic fat with weight gain in South Asians) study, investigated metabolic responses in 14 young, healthy South Asian men and 21 white European men after gaining approximately 5 kg (around 11 pounds) through an overfeeding protocol. The study aimed to understand why South Asians are at a heightened risk for type 2 diabetes, even at lower Body Mass Indexes (BMIs) than white Europeans.

The key finding was a striking disparity in metabolic consequences between the two groups. South Asian men exhibited a 38 per cent decrease in insulin sensitivity—how well the body responds to insulin—following the weight gain, while white European men saw only a 7 per cent decrease. This suggests that South Asian men have a diminished "metabolic buffering capacity," meaning their bodies are less able to cope with the effects of weight gain without adverse consequences.

"This difference in metabolic response may help explain why South Asians have a three to five times higher prevalence of type 2 diabetes than white Europeans," said Professor Jason Gill, Professor of Cardiometabolic Health at the University of Glasgow. "For example, a South Asian person with a BMI of 22 kg/m²—a healthy weight—has an equivalent risk of developing type 2 diabetes as a white European with a BMI of 30 kg/m², the threshold for obesity."

The study also found that the adverse metabolic effects in South Asian men appeared to be linked to fat cell size and distribution. Before weight gain, South Asian men had larger fat cells and were less able to recruit smaller fat cells to store the excess fat. As a result, more fat was likely stored in the liver and other areas, leading to negative metabolic outcomes.

"These findings emphasise the importance of preventing weight gain in South Asian men to reduce their risk of type 2 diabetes," said Dr. James McLaren, Honorary Clinical Senior Lecturer at the University of Glasgow’s Undergraduate Medical School. "Our research also showed that while white European men gained both fat and lean tissue, South Asian men primarily gained fat, which may further exacerbate their risk."

The study's results offer valuable insights into the distinct metabolic challenges faced by South Asian men and underline the need for targeted strategies to prevent type 2 diabetes in this population.

The research was funded by the European Federation of Pharmaceutical Industries Associations (EFPIA)-Innovative Medicines Initiative (IMI) Joint Undertaking-European Medical Information Framework.