Who or what is to be blamed for modern epidemic of obesity?

It's hard to choose the main cause for epidemic of obesity in modern world, but parents play a huge role in this wide-spread problem. They give bad example for their kids in case of diet and healthy eating. Additionally, they often take their children to fast food restaurants instead of preparing nutritional dish. People rarely change their habits from the past and there is no exception in diet. As a result, there are many grown-ups who eat unhealthy, just like they did when they were young. I am awere there can be little time or energy to feed kids properly, but it's worth it, for their sake.