I think what the film does best is show the far reaching effects of our food system. We basically have government subsidized fast food and corn-based products that are making our population increasingly unhealthy. This leads to a greater reliance on healthcare and medication. Gee, hmm, wonder who this benefits? The system is in dire need of drastic overhaul, and only a few seem to want to implement change. It is absolutely maddening, but the more people who really know the literal crap they are being fed, the more hope there is to change these practices for the better.
There are some great posts and articles relating to the film and it's message on their blog, Hungry for Change. The easiest way to protest our food system is to refuse to buy their product. Shop at your local farmers' market and make sure to buy local and organic at the grocery store.