I have been on Wellbutrin for a number of years now. And I agree, in the beginning, I lost weight. I was full of energy. Now, that it's stabilized, I've gained weight on it. Too much weight. I'm pre diabetic now.
And yes, I'm going to the gym @5 times a week; @ 2 hours each time.
Since I quit smoking, it's even worse.
So, I don't think it's the wonder cure of weight issues many people think it is.
Shalom!