How to change the food saturation level in server

I want to code a plugin to change the food saturation level in my server just like the LifeBoat SurviveGames.Anyone know how to do?

http://minecraft.gamepedia.com/Hunger

He wants to know how to actually manipulate the hunger bar with code.

I know but it help him. And i think he must know packet id

I think that it's impossible until PocketMine will add HungerBarRefill etc. to the code

*impossible *actually possible
Try WilliamTDR's Katana project! It has bugs like...the signs aren't visible etc. It doesn't save the world too!
https://github.com/williamtdr/Katana

Yes, this is possible. But you can't do it in normal PocketMine.

You can everything is possible

Katana is from normal pocketmine too xD

Actually, PocketMine has implemented the Attributes API. However, I admit that it is really terrible. You can do little using that API, but I believe that that API allows you to change hunger.
As for sending packets, it is a bad idea because PocketMine itself sends Attribute update packets as well, and they would compete with each other and confuse the player.

so can i change xp using atributes?

Yes, according to the source code, but there may be a trick needed.
I used addAttribute for Katana, not sure how it works on PocketMine mcpe-0.12