<i>I think we have to question the science when he states that exercise is an inefficient tool for weight loss.</i><p>The science of the book is sound. And he is right about exercise: it's good for fitness (as in muscle) and other health reasons, but for weight loss is almost useless by itself. The reason is insulin, which signal the body to store, not use, energy.<p>Of course you could calorie-count people on a high carb diet and whip them to exercise and they will probably lose weight. But you will also destroy their health and they will regain all of its former weight (and then some) later. This is documented and is all in the book too.