The Saturation Bar should be reset when the games are about to start. If you do not know what it is, Click on one of the links. http://www.minecraftwiki.net/wiki/Hunger The Saturation Bar is kind of like a "Second Hunger Bar". When it empties, The Normal Hunger Bar is able to empty. When you start a Survival Game, the Saturation Bar is empty, allowing your Hunger Bar to lower very quickly. When you start a Normal Minecraft World, the Saturation Bar is full, allowing for a buffer, so you can find food before you die.