Why are Americans so Fat?

This article in the nyt last month makes a good argument as to one cause. Agricultural subsidies are primarily directed towards a few crops, including corn and soybeans. This makes the goods derived from these crops, such as high fructose corn syrup, cheaper, while making other produce, such as carrots, oranges, etc more expensive. This means that healthier food ends up being a luxury good.

So why are we subsidizing farmers at all? As technology advances, fewer people can grow more crops, which lowers demand for farmers overall. Of course this has been true forever, and job churning, while painful to the individual, is exceedingly good for society as a whole (or else 90% of us would still be farmers). These subsidies probably have an adverse impact on immigration also, as poorer countries like Mexico depend more on agriculture and can have difficulty competing with subsidized US crops, which pushes Mexican workers across the border.

Ah, the government, encouraging illegal immigration and obesity in one fell swoop. But hey, ban trans fats, because that's a lot easier than acknowledging where the real problems come from.