Low Calorie Cat Food I Believe My Cat Is A Bit Overweight, Good Over The Counter Low Calorie Foods? (pic Included)

I believe my cat is a bit overweight, good over the counter low calorie foods? (pic included) - low calorie cat food

I am not a cat expert, but I think my cat is a little on the chubby.
http://i66.photobucket.com/albums/h258/Druidess79/Bast.jpg

It was two years ago about a year, I was sterile. Since then he has gain weight and not as active as in the past. What a good diet on the calorie counter, which could feed him.
I have to free them, but a month ago, and listened only to feed him twice a day feeding. So far no change.
I feed her Purina Friskies Dry Blend business.

Thank you!