My cats are exclusively inside. I feed dry Science Diet 24/7 and wet Royal Canin baby cat food mixed with Blue Buffalo wet once a day (would do it more often but the silly Bear is old and is eating less). Bear has irritable bowel so that is why the SD Sensitive Stomach is put down for both (both Bear and Socrates eat from each other's bowls when the other isn't looking) and he's eating so little and losing weight that I've added the canned and add baby food to up the calories. And I switch around the flavors on the Blue Buffalo to keep him interested too.
And yes, you are supposed to feel GUILTY!! You're their human ;-)