This book by the son of nutrition pioneer Nathan Pritikin focuses on the reasons diets so often fail. Pritikin describes his theory on the "fat instinct," which he describes as a genetic trait that causes humans to crave fatty foods and conserve energy. Despite the somewhat gimmicky term "fat instinct," Pritikin's advice is sound and in line with what most nutrition experts are saying now about weight control: You need to exercise, eat smartly and consistently. Pritikin addresses some of the biggest controversies in nutrition, including a critique of high-protein diets and a discussion of whether carbohydrates cause weight gain. The last third of the book is devoted to recipes and menu planning.