I would call it a diet book, but this is NOT another fad diet book. It is not simply a diet to try for a few months to lose weight (although that would work), its a book about changing your entire eating habits, permanently eliminating added sugar (naturally natural sugar is ok but "The new Added Sugar Busters" isn't exactly catchy) from your diet, snacking healthily, showing you which foods are healthy and unhealthy (you may be in for some surprises) and talking about why their is so much added sugar in modern diets and how to steer you and your family away from it. The diet is scientifically sound, though the explanation is rather complex, the core of it is easy to grasp. However, the reason I have rated this so highly is.. this book is not just a list of how to eat healthy, reading it actually makes you want to follow it and start chopping off added sugar from your diet. And the more you read it, the deeper it digs into your brain, until you get to the end of it and find that you are surprised at how health concious you suddenly are, and how you feel you can start moving towards healthier eating and living the second you get through it. This book doesn't promise any miracles, and it still requires some effort, but if you stick with it, it delivers. It also has good advice for diabetics, and I ran by a nurse just to make sure.
Overall I completely recommend this book.
The new edition isn't much different from the older editions, but clarifies a few things and has testimonials from many people for whom the diet has worked. Its probably not worth buying again if you already bought it.