People who are overweight may be more likely to develop asthma than people who are of average weight, according to researchers who examined the results of several asthma studies. By examining results from more than 300,000 patients, the researchers found that asthma was 50 percent more common among overweight and obese adults. The study also showed that even in cases where a person is not asthmatic, obesity could hinder lung function, which might cause symptoms that are similar to those of asthma.