Cat needs more cardio

SoDamnHungry

Ha, this is actually a question!

My cat is fat. He was fat before I got him, and remains fat. Not even cutely chubby. There's just a whole lot of cat. He used to be a feral cat, so he wants to go outdoors. However, I don't know if he'll run away, and I'm sure he'll kill the local wildlife. So the solution (at least I'm hoping it can be the solution) is to train him to walk on a leash! I know it can be done, but was wondering if any of you had done it successfully, and any tips you might have.

Thanks in advance!