Let's see what these scientists explain :
In this latest study, researchers used lab experiments to show that infection with a common virus that causes respiratory and eye infections in humans, called human adenovirus-36 (Ad-36) turns adult stem cells retrieved from fat tissue into fat cells. But stem cells that were not exposed to Ad-36 did not turn into fat cells.
Well, how do they explain that only certain country folks are more obese than others? In particular, almost every Americans are fat and obese. Take for example, those contestants on American Idols. They are 80% fat.
The way I see it, blaming it on genes and viruses are good ways to kill the guilt of one overeating, lacking in exercise and basically unhealthy lifestyle.
(source from medicalnews)