This could — should — be the last diet book you will need. It’s colourful, readable, personable, richly informed, expert and just, well… right .... Lieberman is not a nutritionist, which is one of many reasons to like him ... He is a Harvard professor who has written books on the science of exercise and the evolution of the human body ... It can be a funny book as well as a trenchant one. But what is its answer? It is almost disappointingly sensible. Eat more plants and more fibre. Eat less sugar, less fat, less saturated fat and fewer refined carbohydrates. Avoid highly processed foods. Exercise.