Our ingenuity in feeding ourselves is prodigious, but at various points our technologies come into conflict with nature's ways of doing things, as when we seek to maximize efficiency by planting crops or raising animals in vast mono-cultures. This is something nature never does, always and for good reasons practicing diversity instead. A great many of the health and environmental problems created by our food system owe to our attempts to oversimplify nature's complexities, at both the growing and the eating ends of our food chain.

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.

People who snack sometimes sometimes eat kind of thoughtlessly and end up eating a lot more. But in principle, it's a really good idea if you can exert the kind of discipline needed.

One of the reasons we eat fast food is that we don't have to cook fast food. We are out-sourcing cooking to corporations, they tend to cook with far too much salt, fat, and sugar.

Any kind of food you eat is going to have an impact on the world. If you switch to tofu and get off meat, the soy bean is doing enormous damage in the Amazon and all throughout South America.

... the way we eat represents our most profound engagement with the natural world. Daily, our eating turns nature into culture, transforming the body of the world into our bodies and minds.

We are what we eat, it is often said, but of course that's only part of the story. We are what what we eat eats too.