When switching to peaceful (while hungry) my hunger got restored.

After that I switched back to normal. My hunger bar depleted and restored again.
The same thing repeated: 1 hunger, full, 2 hunger, full, 3 hunger, full and so on...

Somehow I was able to eat 5 steaks right after each other.

Reproduce: (Get hungry in normal mode), switch to peaceful, (wait for restore), switch to normal, try to eat until full, run and jump around, repeat previous 2 steps.