a book about spiritual/mental aspect of Water Fasting would be a fabulous thing. This is what is missing on Amazon, unless someone fast because of religious beliefs but then these are not fasting but religious books.
During the fast I came to the very similar feeling/state, (except that I can't describe it so well) about going somewhere far away, usually in desert and staying there watching sunset or just endless sand. Mentally and emotionally it was such beautiful vacation.
We know what is going on physically during fast but it would be interesting to see if there are mental and emotional patterns that one may follow or expect during particular periods.