Elyse I feed Raw anyway but Pennys cats came here on commercial brands.
I have been switching them to raw, and to cooked leftovers and tempting tidbits from the table, they are all losing a bit of weight and enjoying it.

I will tell you this cats are carnivores, not opportunistic omnivores or opportunistic carnivores they are pure carnivores. I do not add any rice grains or vegetables to the cats diet never have never will, and until I see a discovery expose on a lion pride hunting down corn i won"t

That being said, the easiest diets and nutrition is the healthiest for your cat.
I use a simple ratio of organ meats 10% of their total diet, I use meat muscle as nearly 70% I factor in about 10% bone and the rest is supplemented with eggs and fish and yogurt/cottage cheese/sour cream.
It is simple quick and my cats do very very well on it.

Hope that helped