From a personal point of view, when I have been on an extended fast some time ago, the weight would stick and I even remember putting 3-4 lbs on one day, also not losing and not on medication. The body goes into a self-preservation mode, hanging onto it's reserves until food arrives, but this passes and as long as you are feeling well should not be a problem. I cannot say anything about medication, maybe other have some insight. I believe women hang onto fat more than men, but each person is different. I seem to be settling at 1 lb a day.