Carrots

Carrots are the perfect office snack food. They are not messy. You can munch on them and not worry about getting crumbs in your keyoard. Unless of course you have the ability to projectile spit your food while chewing. They take a long time to chew so you don't eat as much. Although I think I have eaten over a pound of carrots this past week. Carrots are crunchy so you can drown out other office noises by eating them.

The only downside I can see is that they might attract bunnies... and that is scary.