Dr. Louis Arrone discusses new research showing some obesity may be caused by virus

Matt Lauer -- Catching a cold is definitely not a lot of fun. For the average American it happens two to four times a year. It causes people to miss nearly 400 million days of work and school, and there's a lot of money spent on fighting those nasty symptoms, nearly $3 billion a year on over-the-counter remedies alone. But now researchers have discovered that one virus behind those sneezes and coughs may have a much more serious side effect: It could make you fat.

It's no secret that America has a weight problem, with some estimates describing more than half the people in this country as obese or overweight. All that fast-food isn't helping, but now a new study suggests poor diet and lack of exercise may not be the only problem. Some types of obesity may be linked to a common virus.

"These findings suggest that when a human is infected with this virus, the virus may be able to do the same to their stem cells and convert them into fat storing cells." said Dr. Nikhil dhurandhar, PhD Louisiana State University. "It turns out about 30 percent of the obese, but only 11 percent of the nonobese people, had been infected in the past with this virus."

So, does this mean that we're on the way to finding a cure for obesity? Some experts say, `not so fast.'

"I don't think viral therapy is going to be the answer to treating obesity. Obesity is a very complex disease, and for all people, obesity is caused by eating more food than is burned up." said Dr. Samuel Klein of Washington University School of Medicine

Researchers don't know why the virus could make some people obese and just give others the sniffles. But more answers could lead to one more weapon in the ongoing battle of the bulge.

•	Dr. Louis Arrone discusses new research showing some obesity may be caused by virus NBC Today Show, Wednesday, Aug. 22, 2007 Byline: Matt Lauer and Ann Curry, anchors