Vegan, low fat, low carb, slow carb: Every diet seems to promise a one-size-fits-all solution to health. But they ignore the diversity of human genes and how they interact with what we eat.

In "Food, Genes, and Culture," renowned ethnobotanist Gary Nabhan shows why the perfect diet for one person could be disastrous for another. If your ancestors were herders in Northern Europe, milk might well provide you with important nutrients, whereas if you re Native American, you have a higher likelihood of lactose intolerance. If your roots lie in the Greek islands, the acclaimed Mediterranean...