Answer
Azteh:
Well, they need more meat than anything, but a balanced diet is made up of grain, meat, and vegetables (for humans, cats, and dogs.). Since a house cat is domesticated, it can't really digest raw meat like tigers and lions can, but big cats are their ancestors, so they are still carnivores. Vegetables are healthy for any animal, but for cats, try to get the cat food who's first ingredient is some sort of meat.
Masterchief:
i am not a professional when it comes to cat diets but i do know that
cats naturally eat grass(at least i think that's what the book said.)
but cats are first an foremost carnivores.
Ken:
No. veggies offer no benefits for cats. It is a filler