One surprise is how deeply the food system is implicated in climate change. I don't think that has really been on people's radar until very recently. 25 to 33 percent of climate change gases can be traced to the food system. I was also surprised that those diseases that we take for granted as what will kill us - heart disease, cancer, diabetes - were virtually unknown 150 years ago, before we began eating this way.

It's been a mystery to me and a disappointment why conversation about health care reform hasn't turned more attention to the subject of food.

Pay more, eat less. Diversify your diet and eat wild foods when you can.

A natural historian is somebody who looks at something in terms of its relationship to the rest of the natural world. You look at things ecologically. When you see a cow on a feedlot, you don't just see a cow; you see a cow that is eating certain food. You follow that food and that food takes you back to a corn field.

Eat food. Not too much. Mostly plants. That, more or less, is the short answer to the supposedly incredibly complicated and confusing question of what we humans should eat in order to be maximally healthy.

Why don't we pay more attention to who our farmers are? We would never be as careless choosing an auto mechanic or babysitter as we are about who grows our food.

The larger meaning here is that mainstream journalists simply cannot talk about things that the two parties agree on; this is the black hole of American politics.