Simon Donner has a great graph showing how our corns -- and thus our heaps and heaps of corn subsidies -- are used. 
A couple notes. There's an interesting chicken-and-the-egg issue here with corn subsidies. Our immense creativity in how we use corn is directly related to the fact that it's been subsidized to the tune of $50 billion over the past 10 years. Since it's artificially cheap, it's artificially ubiquitous. We take corn to the lab to remake it into sweetener, take medicines from the lab to keep cows alive as we force them to feed on it (cows don't digest corn naturally), pump money into ethanol when it's not energy efficient, etc. As Donner says, "frankly, any ingredient that you do not recognize on the label of a processed food or beverage is probably made from corn. Xathan gum? A fermented sugar made from corn. Lecithin? Made from corn. Vanilla extract? Vanilla and corn syrup. Malt extract? Often made from corn, not barely. Dextrin? As Michael Pollan would say, corn, corn, corn."Those are some of the distortions upstream, at the producer level. Downstream, at the consumer level, meat is much cheaper, sweetened foods are much cheaper, ethanol seems like a good idea, and so on. And as you might imagine, pumping subsidies into cheaper red meat and sweetened sodas is not exactly the sort of thing you'd do if you were setting policy with public health, or future health costs, in mind.
A couple notes. There's an interesting chicken-and-the-egg issue here with corn subsidies. Our immense creativity in how we use corn is directly related to the fact that it's been subsidized to the tune of $50 billion over the past 10 years. Since it's artificially cheap, it's artificially ubiquitous. We take corn to the lab to remake it into sweetener, take medicines from the lab to keep cows alive as we force them to feed on it (cows don't digest corn naturally), pump money into ethanol when it's not energy efficient, etc. As Donner says, "frankly, any ingredient that you do not recognize on the label of a processed food or beverage is probably made from corn. Xathan gum? A fermented sugar made from corn. Lecithin? Made from corn. Vanilla extract? Vanilla and corn syrup. Malt extract? Often made from corn, not barely. Dextrin? As Michael Pollan would say, corn, corn, corn."Those are some of the distortions upstream, at the producer level. Downstream, at the consumer level, meat is much cheaper, sweetened foods are much cheaper, ethanol seems like a good idea, and so on. And as you might imagine, pumping subsidies into cheaper red meat and sweetened sodas is not exactly the sort of thing you'd do if you were setting policy with public health, or future health costs, in mind. 
