I experienced this when i was training for my ride, i would get in from a long ride (more than 2 hours) and just be soooooooooo hungry! I found the trick is to eat something low-mod GI that fits in with your plan, of a normal 'snack size' (eg ONE piece of toast), have a big drink of water (at least a pint) then go do something else, and only have something else if you are still hungry 30 mins later! Don't eat a mountain of pasta, thinking 'I need it' cos that is just the old Chatterbox playing tricks on you! I have to tell myself 'being a bit hungry is ok, it's not going to hurt you', cos otherwise i get v v panicky!
I still do long rides, exercise dvds, Pilates and kickboxing, and occasionally run (but i don't like it, i'm trying to learn to like it!). When I was SS, all I did was Pilates and walking, and just doing this helped me get into the exercise habit, which i've definitely got now - I got back from a 400+km charity bike ride in India 3 weeks ago! Pilates is great, it really changes your body shape and gives you a flatter tum. I could NEVER have done as much as I do now when I was SS!