Corn is a subsidized crop by the US Department of Agriculture—we pay farmers to grow it. See the documentary "King Corn" about two guys who didn't know the first thing about growing corn but still made a profit on 1 acre of corn [1].
It's often said your zip code is a huge indicator of many demographic stats and what food you have access to is one of them.
I've lived in food deserts and I can tell you getting healthy food can be quite an arduous task, especially if you rely on public transportation.
Recent data shows that 80%(!) of black women in the United States are obese [2].
This isn't an organic phenomenon; this level of obesity is the result of a system—some intentional and some not—at work.
[2]: https://minorityhealth.hhs.gov/omh/browse.aspx?lvl=4&lvlid=2...