The reason coffee keeps you awake is because the caffeine in coffee acts as a poison (it's not enough to kill you, don't worry) which kills some of the cells in your body that tell you to go to sleep.

(This is partially wrong I'm sorry, the caffeine wraps itself around the cells telling your body to sleep. Your brain chemicals 'freak out' and release adrenaline.)

And yet 5 cups of coffee a day is supposed to be healthy? XD I call BS.

~Kat