Obesity is a growing problem around the world. In the United States, for example, almost one-third of the adult population is overweight.
Now studies at the University of Wisconsin indicate some obesity may be linked to a form of virus. VOA's Jim Bertel has more in this report produced by Pat Harris .
In many cases, people become overweight because they take in more calories than they burn up. The extra pounds they accumulate can be bad for their health. Now new research shows weight gain may also be the result of a type of virus. They are called adenoviruses, and they cause infections.
People may get a cold or flu, recover, and then start to gain weight.
Dr. Leah Whigman, a Nutritional Scientist at the University of Wisconsin says, "There's more than 50 adenoviruses. We've studied just a handful of those as far as their ability to cause obesity or increased fat in different animals."
When results indicated the AD36 virus causes obesity in animals and is associated with obesity in humans, Dr. Whigman and her colleagues tested related viruses on several groups of chickens.
"The chickens infected with the AD37 virus had three times more visceral fat and about twice as much total body fat," she said.
Endocrinologist Frank Greenway of the Louisiana State University says some people do appear to get larger after suffering from a virus.
"When I first heard that obesity might be caused by a virus, I was quite surprised," he said. "Now, I don't think that viruses are causing the whole problem, but they may well be part of it."
Researchers say viruses may not be the main reason why people gain weight, but it seems to be a factor. It's another reason to try to avoid colds and flu!