Food, Inc.

What happens when a people make efficiency the highest priority with regards to their food supply? Why you get 21st century America. The documentary Food, Inc. covers quite a bit of ground in its 94 minutes, the result is nothing new if you've been following this issue for several years. That isn't necessarily a bad thing; if you are new to the ways of understanding how food is grown, distributed, and consumed in the U.S. then director Robert Kenner's film is as good a place as any to start. He includes statistics, some dark humor, and some engaging interviews.
The trouble with efficiency, Kenner and many, many others argue, is that you end up with a few companies controlling a centralized food supply that is heavily dependant on petroleum, subsidizes food that is calorie-heavy and nutrient poor, and creates a culture where bad food is cheaper than healthier.
Again, Food, Inc. is good if you are new to this, and even if you aren't new you might find something to learn, but to dig deeper one should start with the master: Wendell Berry and move out from there.