I always see cat food with labels like "sweet potato" and "fish and rice".

Motherfucker since when did cats hunt sweet potatoes or rice???

They add a shit ton of filler they probably shouldn't be having.

Also it is pretty new for cats to be "indoor only", isn't it? That probably has a lot to do with their weight issues. People used to just let them go buck wild but now it's a known ecosystem issue and also dangerous with cars.