But that could be an effect of people being hungrier, rather than the cause. I think the most convincing clue that there is something nonobvious going on is th

But that could be an effect of people being hungrier, rather than the cause. I think the most convincing clue that there is something nonobvious going on is that lab animals are also getting fatter, despite being on a standardized and controlled diet (http://www.nature.com/news/2010/101124/full/news.2010.628.html http://www.nature.com/news/2010/101124/full/news.2010.628.ht...).