This book dealt quite a lot with the emotional and spiritual effects of long-term fasting. While being of some interest, as I haven't seen these topics discussed much elsewhere, there wasn't a lot of science to go on here. This had the effect of making much of the book seem rather New Agey. Having read another of the author's books (as well as the appendix), I know he does actually do research into the science of things, so it would've been nice to have some here. Also, I quite disagree with the idea of doing a low-fat diet to prepare for a fast. Doing a low-carbohydrate diet would make a lot more sense, as it would tend to jump-start ketogenesis and thus ease the way into the fast. So I was a bit disappointed with parts of this book. Still, the parts on emotional/spiritual ramifications may be of interest to anyone considering a long-term fast. The idea of a vision quest is an interesting one and is something I might consider doing later in life. That's probably my favorite takeaway from the book. ( )