It means as an American that's all you eat. Take a look at the ingredients of the things you buy at the
food bowl grocery store, I know I'm totally out there sorry. Corn is god. It's bad for you. It's sad ... disturbing and nauseating to say the least. Farmers are forced to grow corn. We eat sick animals = sick people.
Investigate a little. It really isn't hard to figure out once you're comfortable with your tinfoil hat, I am :D . Have a great weekend.