The Ohio State study reports that the typical woman will gain an average of 7-9lbs over her four years of college, and the typical man is looking at 12-13lbs. And hey, some of that may be due to the fact that people may still be growing and filling out.
Post-graduation, weight gain continues at an average of 1.5lbs per year, a trend that can quickly add up if you're not careful. So while there's no need to fear the initial body-shock of the freshman 15, there's something to be said for being conscious of health and lifestyle choices throughout all four years.
College is the time when most people transition into independent, (semi-)functioning adults. While 2am pizza is a delight that can be experienced well into adulthood, it starts to take its toll the older you are. The bottom line, as always: college kids, stop complaining. You don't know how good you have it.