Based on the research on fasting, people fasting for 2-5 days tend to loose an average of .57 pound a day (all fat), which so far seems consistent with me. The only "re-gain" I have seen is the weight of the food I've ingested the day following breaking the fast. Of course, that isn't real weight, so so-far, I'm satisfied with the results of fasting from a weight perspective. I'll wait a few months to have the doctor re-test to see if any of my metabolism or inflammation markers improve (which I'm expecting)