I agree totally with your gestalt experience Chazn. Fasting is described as digesting the stores within our bodies and in doing so taking exactly what it needs to survive. So we are almost guaranteed to get perfect nutrition as opposed to when we are eating questionable processed foods which are also taking a lot more of our energy to digest. Detoxing can take a lot of energy also though, and the whole body is being cleansed on a cellular level. Also who knows what nasties are inside our bodies that we don't know about- chronic illnesses even tumours etc, and anything not native to the body will be either digested or broken down and flushed out. So we do need to be prepared to rest, but the other is also true, that we should be prepared to make use of the extra energy released as well. :)