It is well established that obesity in adults contributes to asthma. This was also believed to be true for children — but according to a new, landmark study, it’s the other way round: Asthma in children may be a contributing factor to childhood obesity.

The study, published in European Respiratory Journal, is the largest yet on the relationship between childhood asthma and obesity, conducted by a team of 40 scientists and involving more than 21,000 children participants who had been diagnosed with asthma between ages 3 and 4 and monitored for any related health problems till 8 years of age.

The team found that children with asthma had a 66% greater chance of becoming obese, while those with persistent wheezing had a 50% greater chance, compared with children who did not have asthma or experience wheezing. In general, it was also found that children with active asthma were twice as likely to become obese than those without asthma and wheezing. The findings give firm backing to previous smaller studies with similar observations.

For India, which has the second-highest population of obese children in the world at 14.4 million, and where asthma rates are rising, these findings could help inform policies and interventions aimed at curbing both. Currently, about 10%-15% children in India between ages 5 and 11 suffer from asthma.

The science behind what links asthma and obesity is still unclear. For now, it can be said that because asthma is perceived as an ailment that limits children’s physical activity, it can lead to actual curbs on their activity and thus an accumulation of body fat. Further, corticosteroid drugs taken to treat asthma are believed to increase risk of obesity, and as per the study, children who were prescribed these medications showed the strongest risk of developing obesity. However, many other factors have been linked to childhood obesity, so these theories aren’t the whole story. More research is needed, say the study authors.

“Asthma may contribute to the obesity epidemic. We urgently need to know if prevention and adequate treatment of asthma can reduce the trajectory toward obesity,” says Frank Gilliland, Professor of Preventive Medicine at the Keck School of Medicine.

Senior author Lida Chatzi, professor of preventive medicine at University of South Carolina adds, “[A sthma] a chronic childhood disorder and if it increases the risk of obesity, we can advise parents and physicians on how to treat it and intervene to help young children grow up to enjoy healthy, adult lives.”