The Omnivore's Dilemma, as author Michael Pollan sees it, is the horrendously complicated process of how Americans today go about answering the simple question of what to have for dinner. Fortunately, we have a writer as skilled as Pollan to uncover what happens to our food before it gets to our mouths, and how we can use the knowledge we gain along the way to nourish our bodies as well as our minds. Subtitled A Natural History of Four Meals, the book tells us not just what we're eating, but where it comes from, how it gets to our plates, and what impact those processes have on the world we live in.

Pollan's genius is in both how he structures the book and how he uses the characters behind each meal to engage the reader; it's clear this guy knows a thing or two about storytelling, not to mention food.

Those with a weak stomach, be warned: Part I, in which we are introduced to the industrial food chain that flows on a "river of corn," is a tough read. Most of us know in the deeply denied backs of our minds that life for a steer on a factory farm is pretty grim, and as Pollan follows "cow 534" from ranch to feedlot, even the most carnivorous among us may lose our appetites. But it's not just the treatment of animals one finds troubling here; it's the degree to which our entire food chain is awash in corn, and the implications that has for public health, the environment, and the economy of the Heartland, that is most unpalatable.

To bring the point home, we meet George Naylor, the Iowa farmer who understands exactly what he's doing as he sells corn for less and less money every year, why his grandfather's multi-crop farm made so much more sense, and ultimately, why he can't afford to change anything he's doing.

One's appetite improves somewhat in Part II, which takes us through the world of "Big Organic," or as Pollan dubs this section's meal, "supermarket pastoral." On the one hand, the more we buy from large-scale organic farms, the supposedly healthier our food is, not to mention the people working the fields where pesticides aren't sprayed, and the waters in which chemical fertilizers don't wind up killing all of the downstream marine life. Unfortunately, all that organic produce we feel so virtuous for buying? It's shipped thousands of miles in many cases, particularly to those of us on the East Coast, and the carbon footprint created is significant.

Gene Kahn comes to symbolize the contradictions at the heart of Big Organic. Once a pioneering hippie founder of the organic movement, Kahn is now a General Mills vice president running Cascadian Farms, the massive organic operation that supplies a great deal of what we purchase at Whole Foods.

And then, as soon as have a grasp of what big business has done to our food system, Pollan takes an abrupt left turn in Part III, and spends about 100 pages talking about grass farming. Yep, from the point of view of Joel Salatin, the "Christian-conservative-libertarian-environmentalist-lunatic farmer," it's all about what you do with a pasture. Salatin's Polyface Farm becomes in many ways, the ideal the book is searching for. It's practically off the grid, but it still finds a way to prosper economically because its efficiencies aren't dictated by the free market; they're based on how nature itself works. By harmonizing Polyface's operations with the natural world, Salatin is a throwback, but given what Pollan has to say about the meal, this crazy farmer is doing something right.

The fourth and final meal occupies the rest of the book, and since it's primarily acquired by hunting and gathering, two omnivorous dilemmas are central to Part IV: the ethics of meat eating and, with respect to mushrooms, how do we know which ones won't kill us? Pollan devotes a great deal of energy (and angst) to the first question, and it's a great service to all of us who've ever flirted with vegetarianism. The second question, in which he ventures to the top of the snowy Sierras to forage for fungi, is no less fascinating. As are his hunting and foraging companions. One of these is Angelo Garro, a Sicilian archetype of the "slow food" movement, who guides the author through the sometimes bloody world of the 21st-century hunter-gatherer, at least as far as one who resides in Berkeley, California, can be spoken of in such terms. Ultimately, Pollan's "last supper" is probably the most satisfying, but it requires the most work on his part, and as he points out, it's not an option for most of us. What is an option, now that we've learned where our food comes from, is to make more conscious choices about what we eat. We may just figure out what to have for dinner after all.