Creative hunger and water timers

If this was intentional then disregard this as I can see why it could be:
When a player goes in to creative their hunger and water timers are stopped but when switching back they catch up, rather quickly. If the player has been in creative for a prolonged period this can cause their hunger and water bar to completely empty, which then causes them to start taking damage and if the period is long enough then they will die pretty quickly as their nutrition and health will drop along with it.

The thing that makes me think this wasn't intentional is that the timers are stopped. If the timers are stopped and then catch up when they switch you could, in theory, just leave them running and achieve the same result.