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; a grilled chicken and a chocolate soufflé; made from sustainable farm animals and local ingredients; and a meal he foraged and hunted and ate with some help from friends, right down to mushrooms and wild pig.

Pollan isn't new to writing about food and environmental ethics. His book career began with Second Nature, a classic on the challenge of making a garden and attempting to live in harmony with creation; it's a book I re–read every spring. His engrossing third book, The Botany of Desire, traces the co–evolution of society with four plants (tulips, apples, potatoes, and marijuana). In all of his books, including this one, Pollan brings lucid and rich prose to the table, an enthusiasm for his topic, interesting anecdotes, a journalist's passion for research, an ability to poke fun at himself, and an appreciation for historical context.

In The Omnivore's Dilemma, Pollan tackles some daunting questions. What ethics are involved in our food choices? What impact do they have on the environment? And who or what are we subsidizing with our food choices?

This is not Fast Food Nation; Pollan tends to be more thoughtful than reactive, and he takes things far beyond the golden arches and having it your way. In his first section, devoted to convenience food, he traces much of the cheap food America eats (and the plight of American agriculture) to the super–abundance and government subsidizing of corn. His research is startling. Corn has found its way into a large percentage of the foods we eat: canned fruit, mayonnaise, vitamins, and cake mixes just for starters, raising a myriad of questions. How could a McDonald's chicken nugget be composed of 38 ingredients, 13 derived from corn? What does it mean to eat beef, chicken, or even salmon largely raised on corn?

Pollan shows that corn–fed animals and fish don't have the same nutritional value as grass–fed animals; farmed salmon, for example, do not have the same omega–3 levels as their wild counterparts. By changing the diet of the animals we raise, we are changing ourselves. And it only takes a look at the soaring obesity rates to realize it is not for the better.

But the two portions of The Omnivore's Dilemma that I found most engaging explored the organic food industry (an oxymoron in itself) and sustainable farming. In the segment on sustainable agriculture (which he comes closest to idealizing of any of the four food systems), Pollan lauds a small Christian operation called Polyface Farms in Virginia as a model of what agriculture can aspire to. By using a more holistic, humane approach to land use and consuming locally and seasonally, rather than globally, sustainable farming seems to solve many of the problems created by industrial agriculture. Good reading, although many will wonder if it's viable on a large scale. To function on an ongoing basis, this sort of agriculture requires a heart–and–mind change on the part of the consumer. No small thing.