I wanted to bring this up because not only are you unable to change Woody back to a human, but you get stuck as an invincible Werebeaver until the end of time. I ate logs and it refilled my meter, but every time it hit Zero, nothing happened. I saved and exited, hoping to fix the problem. But my save data was corrupt! (Unfortunately, I did not screenshot this)
I'm a bit late on reporting this, but better late then never!
Werebeaver meter hit zero and never changed back. It's possible that I ate a log right when it hit zero, but I am unsure