It's like your way of saying sorry to your body of all the bad stuff you have given it. This is part of NATURAL HUMAN NATURE.
Could you clarify this a little? At first blush this wouldn't seem to be the case--I don't think our bodies adopt fasts are part of its nature. Quite the opposite, really: it seems that it is human nature to eat.
I've never really fasted. About the wackiest think I've done with food is a few times I went on a diet of basically nuts, soups, and wheat grass. The concept behind such a diet (and I don't know if this is "flaky" or scientifically validated) is to eat foods which metabolize to alkaline by-products. The claim is that we eat too many foods that metabolize to acidic products, these accumulate in our body, and create health problems.
I've done this a couple of times for a week or two, and I don't know if the claims are valid or not, but in general I felt very healthy during the process. This makes sense, though: you're basically eating nuts and vegetables and a few fruits for a week or two, and these are good foods that are good for you!
About the only "body cleansing" that I do with any regularity is ritual purging with certain entheogenic medicines. This takes only an evening, though, and afterwards one tends to feel pretty good.
