It would be an interesting (if difficult) experiment but from what I know wild animals will absolutely gorge themselves if they can.

The difference is that in the wild, this is tends to be quickly followed by a resource crash from a normal cycle (e.g. winter crash after summer glut) and / or population explosion.

I don't know that any organism has had evolutionary-scale periods over which to psychologically integrate an access to essentially unlimited (in time and quantity both) resources.