weight gain-can it be reversed

Hello folks. I took Remeron in the past, and the only reason I stopped taking it was the weight gain (about 15-20) pounds. Other than that, the med worked well. My depression is in full-swing, other meds have had too many horrible side-effects (among them, paranoia), and I'm considering trying Remeron again. Does anyone have any experience with reversing the weight-gain, i.e., exercise, resisting the "munchies" that Remeron presents, etc. I did read somewhere that the weight gain does eventually turn around.