It seems that the use of (heavily subsidized) corn as a cheap universal feed for chickens, for cows, and even for fish, not to mention the corn products that seep into candy, soft drinks, cheese, and almost everything else, has made that particular package of starch nearly inescapable.

NEWYORKER: Food, Inc.

We also use corn to make high-fructose corn syrup that's used in many foods and soft drinks.

NPR: Biofuels and Food Prices