Early in Robert Kenner’s polemical documentary, Eric Schlosser, author of Fast Food Nation, says: “The industry doesn’t want you to know the truth about what you’re eating — because if you knew, you might not want to eat it.” Kenner all too believably proves it in an uncomfortable indictment of how the majority of US food production — animal and vegetable — is controlled by big business. This passionate film is undoubtedly one-sided but still very effective.