Explore all of the food stores around your university for the best deals on groceries — some stores will sell the same product at a higher markup than others. You may also be able to find coupons and deals either in-store or online.
Of course, being in university doesn't mean you can't indulge yourself. Take the bite out of restaurant costs by choosing water over expensive drinks, or splitting an appetizer (and its cost) with your friends. Decide what makes the most sense for you between classes, whether it's packing a lunch you can eat near class, stopping at a cafe, or picking up a bargain takeout meal.