For years, the bestseller lists have been dominated by books urging people to eat plenty of meat and fat but to shun carbohydrates. The Atkins Diet led the parade; but there have been many imitators, such as the Zone, the South Beach Diet, the Paleo Diet, and the Dukan Diet. Even some of the vegan-oriented books encourage people to avoid starches. Yet the scientific evidence shows us that human beings are specifically adapted to thrive on a starchy diet. So I was delighted to see that the title of Dr. John McDougall’s latest book is The Starch Solution. He explains something that nutritional epidemiologists and experts on clinical nutrition have known for many years, namely that human beings stay naturally slim and healthy on a diet based on unrefined starches and vegetables.