I'm pretty much in the same boat. I fasted pre- and for a while post-workout for a few months. Since the beginning of the year, I've added a pre-workout snack of a can of sardines + a small apple or small sweet potato, an hour or two before I workout. Then I break my fast as soon post-workout as possible. When I was fasting, I still maintained my weight, but since I've added calories peri-workout, I've gained a good bit, about 5-6 pounds over about 3-4 months.