Putting on weight, as a "Belly Flap" is normal for "Middle Aged" cats that have been spayed or neutered. No matter how much baby begs for treats, don't give in with fattening foods. Just like people they get that "Middle Aged Spread" of my 9 babies, about half are 6 years old and older, and have small "Flaps" treats and too much food will do that... Isn't it wonderful how the kitties are like little humans....