Forget religious leaders—Americans feel spiritually vacant without a dieting guru, and we've been without one since that rumored Atkins heart attack incident. I'd like to nominate cookbook author and New York Times columnist Mark Bittman to fill the vacancy.

Bittman is a practical, no-nonsense advocate for home cooking—one imagines that if you told him that you're "just not a good cook," he'd hand you a copy of his invaluable How to Cook Everything and tell you to get over yourself. His new book Food Matters is equal parts environmental polemic and diet plan, couched in accessible pragmatism and prompted, Bittman says, by a UN report that attributed one-fifth of the world's greenhouse gases to livestock production. To put that number in perspective: "Eating a typical family-of-four steak dinner is the rough equivalent, energy-wise, of driving around in an SUV for three hours while leaving the lights on at home." The solution to both global warming and imminent fatness? Eat more plants.

But wait, didn't Michael Pollan already tell us that? Well, yes, but Pollan didn't provide 100-plus pages of recipes explaining how exactly one goes about it. And other than the highly sensible edict of getting as many of your calories as possible from plant sources and avoiding over-processed junk food, the Food Matters diet isn't particularly prescriptive—where Pollan ad- vocates eating locally, Bittman's focus is on mitigating the effects of industrial farming by reducing the amount of meat in the average diet.

"I think the answer is, eat any vegetables you can," he tells me in a phone interview from San Francisco. "I have no problem with locavorism, I have no problem with organic food, but I don't think that those are the primary solutions. Organic is well and good, but you cannot produce meat in the numbers we produce it now and make it well. You can call for grass-fed beef or you can call for organic beef and that still doesn't solve the basic problem: The land isn't there for it. The water isn't there for it." And what's good for the environment is good for the waistline, as consumption of meat and processed corn syrup aren't doing anyone any favors.

"At this point it's really all about balance. The gist of my argument is to eat more plants. If you want to get one-third of your calories from alcohol and two-thirds from Brussels sprouts, that's still probably better than most people."