Minecraft wiki entry for Your_first_10_minutes, associated text: If you run short on food, you can survive on rotten flesh dropped by zombies, but it is not as nutritious and can poison you with hunger for 30 seconds. If you are living on rotten flesh, it is best to wait until the hunger bar is low and then eat multiple rotten flesh in quick succession, because the hunger penalty doesn't stack (If you do get hunger penalty, stay still to prevent hunger loss).