A vegan in a Hummer has a lighter carbon footprint than a beef eater in a Prius.

Wrangham cites several studies indicating that in fact humans don't do well on raw food: they can't maintain their body weight, and half of the women on a raw-food regimen stop menstruating. Devotees of raw food rely heavily on juicers and blenders, because otherwise they would have to spend as much time chewing as the chimps do. It is difficult, if not impossible, to extract sufficient energy from unprocessed plant matter to power a body with such a big, hungry brain.

Culture, when it comes to food, is of course a fancy word for your mom.

It's more important that you eat vegetables, even if they are conventional -- I'm talking about for your health -- then it is until you wait until you can afford organic, or you can find organic.

Much more has to be done to democratize the food movement. One of the reasons that healthy food is more expensive than unhealthy food is that the government supports unhealthy food and does very little to support healthy food, whether you mean organic or grass-fed or whatever.

Not that I'm against meat eating. But I think we're eating too much.

But carbon 13 [the carbon from corn] doesn't lie, and researchers who have compared the isotopes in the flesh or hair of Americans to those in the same tissues of Mexicans report that it is now we in the North who are the true people of corn.... Compared to us, Mexicans today consume a far more varied carbon diet: the animals they eat still eat grass (until recently, Mexicans regarded feeding corn to livestock as a sacrilege); much of their protein comes from legumes; and they still sweeten their beverages with cane sugar. So that's us: processed corn, walking.