At work, stuck in a chair...

happysquidmuffin

and SO BORED! Are there any kind of exercises I can do at a desk? Also the chair is tilted forward so I constantly feel like I'm going to fall out of it. It's only 11 am here and I am so tempted to start eating ym lunch, but then I'm going to be too hungry by the time I'm off and will be tempted to eat too much for dinner.
NEED MOTIVATION!