There is a strong social bias against such findings because many people want to believe obesity is due to an individual's lack of control on some personal, mental level, but we now think viruses may be a factor.
More research is needed to find out if Ad-37 causes obesity in humans. One study was inconclusive, because only a handful of people showed evidence of infection with Ad-37 - not enough people to draw any conclusions.
In our society, we're used to thinking of obesity as an issue of self-control. We think people aren't disciplined enough to exercise and control the food they eat. But there could be other factors that aren't in their control.