"Eat food. Not too much. Mostly plants."
These cautiously conservative recommendations from this book by Michael Pollan I'm sure are good advice. Humans are descended from a long line of omnivores who found the most readily available food to be plants. Anything sweet such as ripe fruit was more rare and seasonal. With the development of hunting tools humans gained the ability to acquire meat, however the size of the human canine teeth is a good indication that humans are not true carnivores. So it is only logical and reasonable that the best human diet is one that approximates the diet upon which humans evolved.
So as best as I can tell probably everything Pollan says in the book is true mostly. Yet I don't feel completely comfortable with the overall tone of the book. I think the book expresses too much glee in trashing nutritionism, processed foods, and the "western diet." I think the only thing wrong with those three words is that they describe systems that make sweets, salt and fat easily available to humans who evolved from ancestors who were always on the edge of starvation. In other words, I think it's possible to eat the western diet and be healthy if one doesn't eat too much and too often.
So it's a matter of education and motivation which this book does a good job of providing. Do you want to be (1) fat, dumb and happy; or (2) thin, clever and wise? My tongue-in-cheek solution for motivating the masses to eat correctly is to increase the cost of all sugars by a factor of 100, increase the cost of meat and salt by a factor or 10, and keep plant based products at their present low costs. These economic changes would be sure to improve the western diet to a point where only stupid rich people would die of heart disease, diabetes, high blood pressure and cancer. Here I am being guilty of what I've accusing Pollan of doing; expressing too much glee in exposing common diet mistakes.