I heard about this book on a documentary. It's a pretty good book if you are looking into a plant-based diet. I also like that it gives you some facts to back up your beliefs when others may be arguing with you about your choices.
Typically I avoid all diet/nutrition books. A friend recommended this book to me upon hearing that I adopted a Vegetarian diet. This book is fascinating, the research is well backed and surprising. This is an excellent read if you are considering Vegetarianism. If you already are a Vegetarian, this book will help back up your beliefs.