True confessions: I love McDonald's French fries. They're a guilty pleasure. I also enjoy shopping at Whole Foods, the organic grocery chain in my neighborhood. I feel virtuous loading my cart with brown eggs laid by happy chickens in comfortable nests, or eating beef from free-range cows. When I pull a can of Amy's Organic Soup from the shelves I envision Amy and her grandma in an 18th-century restored farmhouse kitchen chopping tomatoes and adjusting spices.

Whole Foods makes a large dent in my pocketbook that I rationalize by saying I'm supporting family farms and putting my money where my mouth is about agricultural reform and organics. Very righteous of me, I'm sure. But true culinary sainthood arrives when I make a pot of chili with the heirloom tomatoes frozen from my garden last summer, or pull a few green spring onions for a dinner salad.  I've even been known to fry up some "dandelion fritters" from our yard, in which the yellow flowers are a star attraction. (We're on shaky terms with some of our suburban neighbors.) This, I think, is eating at its best—fresh, local, and organic.

When I began reading The Omnivore's Dilemma: A Natural History of Four Meals by Michael Pollan, I realized I had some rethinking to do. In this doorstopper of a book, Pollan, a longtime contributing writer to The New York Times Magazine and now a professor of journalism at University of California in Berkley, traces the path of four meals through their various systems: organic food, alternative food, industrial food (such as fast food), and food we forage for ourselves. Each system exploration results in a meal: cheap fast-food take-out from McDonalds eaten in the car; a pricey repast from Whole Foods consumed at the dinner table; ...