In Defense of Food: An Eater's Manifesto gives a good overview of the checkered history of nutrition science (or what could be better termed "nutrient science.") There is a lot we don't know, which doesn't keep parties of all sides from making bold claims. Are Westerners' health problems caused more by a lack of Omega 3's or too much Omega 6? Why is it that nutrient compounds, when separated from their plant sources don't give us the health benefits found when consumed in the plants themselves? What health studies are actually useful and conclusive (not many)? What are scientists really confident of?
Pollan's advice after the review of the literature and hundreds of interviews are this:
"Eat food. Not too much. Mostly plants."
You can break it down further into some basic rules of thumb:
1. Don't eat any single food with more than five ingredients.
2. Eat at a table--(ie: not at your desk or in the car).
3. Eat meals-- combinations of food have arisen for cultural and evolutionary reasons. There are social aspects of eating meals at table that improve our health, as well as the combinations in those meals themslves.
4. Spend more on healthier food (so you likely spend less on health care in the future) and then eat less of it (as the law of demand would imply). This includes having your own small garden plot.
5. Eat a variety.
6. See meat as a side item-- something to be enjoyed with a meal that is mainly vegetables.
Westerners have moved from eating leaves (fresh greens) to seeds (corn, soy), and this poses problems. We've industrialized our food chain and homogenized our products. Now we consume a ton of a few specific items-- like corn, soy, and meat-- which itself has become homogenized.
This book made me think about my own habits of straying toward processed foods so that I hit my calorie and macronutrient targets since I'm working out and lifting weights every day. The USDA's estimations of both micro and macronutrient content of things like produce is highly suspect, since there is a lot of variability based on the quality of soil each fruit and vegetable was grown on. Likewise for cattle, what's the quality of the grass consumed by the "grass-fed cattle" you're eating, and isn't "grass-finished" cattle more important since what they were eating in the feed lot before being slaughtered may not have been grass?
One flaw I might find in the book is the lack of combination with exercise science. Yes, the Europeans eat less and in smaller portions so this might explain their better health than Americans. But they are also more urbanized and walk and stand more, and do more flights of stairs. Building muscle, even in small amounts, effects how your body processes the calories it consumes. That area goes completely unaddressed in the book.
Not nearly as vitriolic or dogmatic as other books on the subject. Pollan is intellectually humble and understands that recommendations put forth today may not be what is put for tomorrow.I recommend it. 4 stars out of 5.