If we get hunger into the game, you should get a warning before losing health, like "You are feeling hungry" and then 10-15 minutes laters, you get the message "You are starving" and lose 1 heart, and if you dont eat, 5 minutes later you use 2 hearts more, and so on, until you lose more hearts then you have health and die (might regenerate health for some reasons like healing springs, but if you keep increasing the amount you lose, no matter the healing, you will die).
It will give food some better meaning then just healing, I got like 3 doublechests full of meat and half of wheat (mainly because Im to lazy to harvest), so should be easy enough to get food. And you can always have a grace periode for new players when they join.
Actually, when you log in, you should get your health/hunger status displayed for you ("You are healthy, but slightly hungry" / "You are hurt badly, but have a full stomach), this also tells the new players that there is something like hunger in the game.
I don't know how long your meals should last, an hour or something maybe. And if new people haven't managed to kill a pig before then...