Last night we went to see Robert Kenner’s documentary Food, Inc. at the Full Frame Documentary Film Festival here in Durham. I should have loved it. The auditorium at the Carolina Theatre was filled to the brim with liberal locavore-loving foodies just like me, secure in the knowledge that our organic herb gardens were sprouting and our CSA deliveries were scheduled for just a couple of weeks away.

But if you’ve been aware of these issues since the 1980s, when you first read Frances Moore Lappe’s Diet for a Small Planet (first published in 1971), and if you grew up on a farm where your grandfather pointed out at every meal that all that you were eating had been grown right there–and more recently, if you read Eric Schlosser’s Fast Food Nation and Michael Pollan’s The Omnivore’s Dilemma–well, you’ve seen Food, Inc. Because the director relies heavily on Schlosser and Pollan’s expertise, large chunks of the film felt like a rehash of these books. We went over the corn thing again (cheap corn makes it cheaper to feed livestock grain instead of grass, leading to factory farms, leading to the need to pump animals full of antibiotics, leading to antibiotic-resistant microbes in the food supply) we spent lots and lots of time with the vocal owner of Polyface Farms, a sustainable operation in Virginia (whom Pollan also interviewed); and we learned, again, that meat packers work in terrible conditions and that chicken farms are dreadful.

It would be wonderful if this film reached a wide audience and brought about more widespread change. For those who haven’t read these materials, the movie will no doubt be eye-opening. And the movie makes specific calls to action in the final sequence that might help us take some practical steps toward making a difference (eat local, reduce meat consumption, and of course, “visit our Web site!”).

They film is optimistic about the future, noting that the actions of consumers can change the market and pointing out that if food conglomerate seem invincible, remember that Big Tobacco, once thought invincible, had been brought down. (Or bought by Nabisco.)

But I was haunted by the thought of Lappe’s book. Her goal was to get Americans to eat in a way that would lead to reduced hunger world wide–largely by drastically reducing meat consumption. Her argument, back in 1971, was based on the idea that our meat production system was terribly inefficient, requiring 21.4 pounds of grain to cattle for every pound of beef we produced. We were misusing agricultural land by deploying it to feed animals rather than people; we should restrict livestock raising to land that couldn’t be used for other agricultural purposes and feed cattle grass instead of grain; and our use of chemical pesticides to produce food in vast quantities was getting into our meat in uncertain and potentially dangerous amounts.

We could change everything, Lappe argued, by eating differently: “The act of putting into your mouth what the earth has grown is perhaps your most direct interaction with the earth . . . . What I will be suggesting in this book is a guideline for eating from the earth that both maximizes the earth’s potential to meet man’s nutritional needs and, at the same time, minimizes the disruption of the earth necessary to sustain him. It’s that simple.”

If only it were.