There just seems to be no end to the problems caused by obesity. Like magicians pulling rabbits out of a hat, researchers keep stumbling upon one disease after another caused by failure to control one's weight.
The latest to join the long list is asthma. It affects the small tubes - airways - that carry air in and out of the lungs.
Those obese have a 50% higher risk of developing asthma, US researchers have concluded after reviewing seven studies involving over 330,000 adult patients.
The study, by a joint team from the US National Jewish Medical and Research Center and University of Colorado, classed normal weight as someone with a body mass index below 25, overweight over 25 but below 30, and obese as 30 and above.
The analysis showed that for every normal weight person with asthma, there were 1.5 people with asthma who were overweight or obese.
The risk of having asthma for those who were obese was twice that of someone with normal weight.
Researchers could not pinpoint what caused the increased risk of asthma, though.
Obesity causes impairments in lung function, such as a reduction in lung volume and an increase in the amount of oxygen used during breathing, but these on its own would not be enough to induce the condition.
UK experts agreed there was a link, but said the reasons were still unclear.
A spokeswoman for Asthma UK said: "There is long-standing evidence that obesity and asthma are linked. This new research attempts to clarify this relationship, however the exact reasons remain unclear."
Anyway the fact remains that reducing weight could help improve the functioning of lungs and thus manage asthma better.
Already overweight and obesity have been held to substantially raise the risk of illness from high blood pressure, high cholesterol, type 2 diabetes, heart disease and stroke, gallbladder disease, arthritis, sleep disturbances and problems breathing, and certain types of cancers. In general higher body weights are associated with higher death rates, it is known.