Being predators cats have a hunger drive that kicks in early to make them look for food before they're too weak to hunt. In nature, cats are usually always a little hungry. Hence, if the food is palatable, most cats will eat constantly and end up eating more than they need by at least some margin.

It's not an active decision by the animal, but rather the hunger drive, which can vary quite a lot between individuals.

This is complicated by the fact that cats are picky, to the point they can outright refuse to eat something they aren't used to, or just eat less of it.

My cat would never stop eating his favorite treat (freeze dried meats), the same cat eats a little too much kibble if I let him, and no wet food at all no matter how hungry he is. This kind of thing, you might argue is a decision.

[–] Slowy@lemmy.world 6 points 1 week ago* (last edited 1 week ago)

I wouldn’t be surprised if it’s as much a decision as it is for many humans. There is some evidence that, for some actions, what we think of as choices may just be retroactive mental explanations for bodily urges which we are in the process of initiating before we get the conscious “idea” to do so.

But individual tendencies and habits formed earlier in life are definitely contributors as well. Both my cats free feed and are lean, but both were raised on scheduled individual feedings for years before I adopted them.