I read Michael Pollans Omnivore's Dilemma before seeing this movie. Of course he's in it and a lot of the data comes from that book as well as Fast Food Nation. The nice thing was that when you put these things in a movie format you humanize it. It's hard to picture miles and miles of stockyards or chicken houses where there isn't any room for a chicken to even walk.
The other thing I'd like to say about the movie is it wasn't built like a Michael Moore movie where you're very clear of the goal (to change your mind) the whole time. It's fairly objective about a lot of things and sometimes you think "Man we need to change" and other times it's just informative.