It's like any other addiction, some people are less prone to lapse in discipline. The difference is that you get to shame people for abusing drugs but not for abusing food. It clearly is not a good tradeoff to eat more in order to skirt respobsibilty, but the piggers can't help it, esps if society cuddles them.  It should be pretty obvious many people use food as a coping mechanism and fatty epidemic is a result of society vecoming harsher. Piggies still got to learn though