You don't have to rely on a cheeseburger for that afternoon energy fix, or a bag of chips for a midnight snack. You have choices out there, from healthy things to not-so-healthy things; and you can have fun things to do while you're having snacks. Part of the fun of enjoying your food is getting to share the experience (not necessarily the food) with somebody else.
Now, then, get some savings together, because you will have to treat yourself some time. Watch this site for more snack ideas - not to mention mini get-together ideas so that you don't end up obsessed with work and study. Work hard, play hard - eat smart.