Adults with obesity are more susceptible to influenza A/H1N1pdm—the swine flu virus, according to a new study that did not, however, find a similar association with the seasonal flu.

The results could be relevant in understanding the mechanisms by which infectious diseases such as influenza or the ongoing coronavirus pandemic might affect different segments of the population, the researchers say.

"This research is important because obesity around the whole world is increasing rapidly. It's approximately tripled since the '70s," said first author Hannah Maier, a postdoctoral fellow at the University of Michigan School of Public Health.

"We're having a lot more obesity, right now we're dealing with the pandemic, and it was just announced that there might be another potential swine flu pandemic. If obesity is associated with increased risk and there's a lot more obesity, that could mean a lot more infections."