My hunger bar will very rapidly deplete when I am running, jumping, swinging etc. then it will regenerate just as quickly even while I am still running. My hunger bar also ignores food and my health will not regenerate when the hunger bar is full. This only seems to happen on my server, but it happens to everyone on it.

Additional note: Although this is a different issue it may be related; my server will reset the difficulty to peaceful whenever I boot it up and will occasionally change gamerules and not allow them to be changed back.