Hills's book has two purposes. To explain why diets fail, and why diet books do not help. (Hence the title). What Hills learned over the course of his dieting is that diets are not all-powerful. That any success a person has while on 1 Hour Belly Blast Diet a diet is not because of the diet itself. It is because of the person. It is the dieter, not the diet, that makes the changes happen. Or not happen. To back this up he breaks down the most popular diets; including Weight Watchers, Jenny Craig, South Beach, and Body for Life. He does not harp on any of these diet plans. In fact, he recommends them all. Because, as he rightly points out, every person is different, thus every diet can aide at least one person. Choosing a diet is a personality match. There is no right way or one way to approach weight loss. Despite the many tag-lines that claim otherwise.