CHICAGO, ILLINOIS: Obese and overweight people are 50% more likely to get asthma than those of normal weight, suggesting that weight loss could help reduce the number of asthma cases, US researchers said on Monday.

Asthma, an inflammatory disease usually triggered by an allergy, can cause wheezing, coughing and laboured breathing that can be life-threatening.

It affects about 7% of the US adult population. Obesity and being overweight are far more prevalent, affecting about 65% of US adults.

Both types of ailments are on the rise and a new study suggests the two may be linked.

"Overweight and obesity significantly increases the risk of developing asthma," said E Rand Sutherland of the National Jewish Medical and Research Center in Denver, Colorado, who wrote the study.

"If you can substantially reduce the amount of overweight or obese people, you might also get a reduction in the number of new cases of asthma," Sutherland said.

Sutherland and colleagues, writing in the April issue of the American Journal of Respiratory and Critical Care Medicine, said a significant reduction in the incidence of overweight people could cut the number of new asthma cases in the US by 250,000 per year.