You can always try candy........... oops,I mean asf's. When they take a rat,right after they swallow it,throw in another. Don't worry about the animal "getting fat", FEEEEEEEEED ME! http://ball-pythons.net/forums/showt...51#post2088351
One more thing...... You are not getting the girl on the weight,you are getting the weight on the girl!
Lol this already sounds like a Hansel and Gretel story to me. I'm going to stick to my guns and say that unless they are looking thin, I wouldn't push their weight.