I'm currently reading Michael Pollan's book In Defense of Food. Pollan is the guy who wrote The Omnivore's Dilemma (and some other books, of course) and he is basically a proponent of what you might call natural eating - eating regular food-type food that isn't too processed or industrial.
I haven't read any of his other stuff, but I'm really enjoying this book. Even though I haven't learned that much actually new material from it, he does give a different perspective, and the way he writes about food is motivational for me.
One thing he opposes is what he calls "nutritionism" - that is, the culturally prevalent practice of talking about foods as though they are just collections of chemicals that have nutritional consequences. An example he brings up is a government panel or committee of some kind in 1977 that was looking at heart disease, and decided to recommend that Americans eat less dairy and meat, since it was pretty clearly associated with increased risk of heart disease. Of course, the dairy and meat industries freaked the fuck out, and the recommendations were changed to, basically, "avoid saturated fat," even though there wasn't good evidence that saturated fat was the problematic aspect of meat and dairy. But by focusing on invisible chemical aspects of foods rather than on foods themselves, the government could make dietary recommendations without earning the wrath of any particular food industries.
The growth of nutritionism has also, in Pollan's view, fostered the industrial approach to food that has our grocery stores full of boxes and bags. Once it's discovered that antioxidants, or fiber, or Omega-3 acids are healthy, then they can be added to cereals, breads, pasta, yogurts, cookies, and all the other foods that industry churns out for us. A recommendation like "eat more fruit" or "hey how about some green veggies" doesn't foster the same kind of innovation in new products. (And in case it's not obvious, it's a lot easier to make big profits on something like cookies than on something like eggplants.)
He delves into quite a bit of nutrition science himself, a contradiction that he acknowledges. But it's not that he rejects science, including nutritional science, as our best tool to understanding what makes some foods healthier than others. What he rejects is using today's limited science to decide what to eat based on a nutritional perspective. (He's also in favor of the idea that people can suffer from "orthorexia," or an obsession with the healthfulness of foods.)
What's clear to Pollan is that the basic culprit behind the diseases of affluence (obesity, heart disease, diabetes, cancer, etc.) is (besides the small contributing factor of longevity) basically the Western Diet itself. Whenever people living on any kind of traditional diet (of which there are quite diverse kinds in the world) change over to a Western diet they get fat and diabetic and all the rest of it.
So his basic advice is, don't eat the Western diet. He begins the book with the (familiar) advice: "Eat food. Mostly plants. Not too much." The last third (perhaps) of the book is devoted to ideas about how to do this - what he calls "algorithms" and I would call "heuristics." He talks about each part separately - what is "food" (vs. a "foodlike product")? What kind of plants are best to eat (lots of variety; more leaves than seeds)? And what kind of cultures of eating should we follow in order to make food healthy as well as emotionally and socially satisfying?
If I lived fully in accordance with my most basic feelings, I would eat like most of my dad's side of the family eats - a lot of fried chicken and other fast food, chain restaurant fare, the occasional home-cooked spaghetti or hamburger. Most of the other side of my family eat a pretty impressive diet of vegetarian (or near-vegetarian), fresh, from-scratch, vegetable-heavy foods - to such an extent that, while I admire it, it's also hard for me to understand how they can do it. And, of course, my dad's side of my family is markedly more obese and has vastly more health problems than my mom's side.
(My Aunt - my mom's sister - tells a story about when I was little. I visited her during the summer, and she had made some beautiful fresh gazpacho from things she had grown in her own garden. When I went home, I told my mom, "...and all we had to eat was frozen tomato soup!" What's funny to me about the story, and about my Aunt's telling it, is that I would feel exactly the same way now if someone served me gazpacho as a meal.)
So I am kind of trying to use education and knowledge to move myself from my western-diet nature (which has me end up like my dad's family) to a diet more like that of my mom's family (which will help me live longer and in better health). I mean, to be clear, I don't think the difference between the two sides of my family is innate - like genetic or whatever. But growing up as I did, in this place and time, what I want is "the good stuff" - the more fried, refined, salted, sweetened, and processed the better.
So I think Michael Pollan's basis thesis is right, and I am finding the book reasonably motivational. (Some of his stuff also reminded me of Sally's hypothetical Navajo talk about eating.) I recommend reading it, and it also makes a very good companion (obviously up the same alley, yet without much overlap) to The End of Overeating.