In short, just a very informative book with several worthy goals. For one, it educates the reader in the inner workings of the human body. It does this quite entertainingly through trivia, facts, and interesting pictures (for instance the authors use a lot of elves). Additionally, the book also gives you many helpful tips on how to keep your body running smoother.
While there is a lot information, I really would like to have seen a reference section at the end of the book to support its advice- some of it could be considered controversial in medical circles (who hasn't had the experience first-hand or at least heard of two doctors disagreeing about the treatment of a medical problem).
All in all, a pretty informative and amusing read, it should enhance the well-being of many. Also recommend "The Sixty-Second Motivator" for readers who have trouble making healthy lifestyle changes.