This might be a question for ILoveBish, since I think he's the only other person regularly fasting.
Since around November of last year, I've been doing a one meal per day thing. Usually it's a fast of between 21 and 27 hours depending on the meal timing. I'm pretty flexibile with when I eat. However, I do have a copious amount of heavy cream in my coffee in the morning, so it's technically not a real fast.
Anyway, one thing I've noticed is that weight training (or intense anaerobic exercise in general) has a strong appetite suppressant effect. I really notice it when I do some heavy (relative, obviously) lifting well into the fast (hour 20 or beyond). I'm well hungry at that point, but midway through the workout, that feeling of hunger disappears. I don't really feel like eating anything after the workout for an hour or so (or even more sometimes).
It's not a problem or anything, but I was wondering if anyone else had experienced anything similar. I did a bit of research and apparently exercise does suppress ghrelin, which may be a cause, but when I used to eat more regularly throughout the day, exercise would always make me hungry, not suppress my appetite.