“Big” is a value in America, and this includes food. I’ve long suspected that portions were generally larger in the United States than the rest of the world, and a quick check shows this to be actually true. This map from theglobaleducationproject.org shows that Americans (and Western Europeans) really do consume substantially more calories than everyone else in the world.
No big surprise here — the the citizens of richer countries do eat more food. The interesting thing is to ask what the actual numbers mean, in terms of health. Simply put, people living in the developed world eat way too much. Oddly, this might mean that the current poor will one day be healthier than the formerly rich.