Do you sprint a lot? Sprinting, and especially sprint-jumping, is very demanding on hunger, but you can walk forever (without jumping) without ever losing any hunger, and 3 hunger bars (6 hunger points) is the point where you can no longer sprint, so at this point hunger would start depleting at a much slower rate (for example, one hunger point lasts for 800 blocks mined but for only 20 sprint-jumps or 80 normal jumps):
Any action not listed here does not increase exhaustion level. For example, normal walking doesn't increase exhaustion, and therefore does not decrease saturation or the food bar.
I've noticed this on a multiplayer and in my own single player world.
Even in hard mode the starvation system only seems to drop to 3 hunger bars. I thought it was meant to kill you?
Do you sprint a lot? Sprinting, and especially sprint-jumping, is very demanding on hunger, but you can walk forever (without jumping) without ever losing any hunger, and 3 hunger bars (6 hunger points) is the point where you can no longer sprint, so at this point hunger would start depleting at a much slower rate (for example, one hunger point lasts for 800 blocks mined but for only 20 sprint-jumps or 80 normal jumps):
TheMasterCaver's First World - possibly the most caved-out world in Minecraft history - includes world download.
TheMasterCaver's World - my own version of Minecraft largely based on my views of how the game should have evolved since 1.6.4.
Why do I still play in 1.6.4?