Did anyone gain weight in the purée stage if so how much?

I didn't, but it's possible to as your body is probably still in the healing phase. So, it's possible that you're swollen.

I am 16 days post op & whilst I haven’t gained I’ve been the same weight for a week. I’m just holding onto the faith that there’s no way I’m eating enough calories to stall or gain so it’s gotta be down to post op internal chemistry!!