What I did when my cat Taffy was like that I put her bowl up on the counter once she finished her food. I simply ignored her and walked away and she would give up after awhile. Taffy doesn't meow that much anymore since I got Misty three weeks ago so maybe your cat needs a buddy to hang out with. Have you suggested in getting it another cat? I wouldn't keep feeding it as if overweight starts to become a problem then health issues can come up like heart problems, diabetes.