For decades, it's been accepted as truth that college students (especially women) will pack on the pounds during their first year of college. The phenomenon was once known as the "freshman 10," (meaning, a 10 pound weight gain) but since the late '80s, it's escalated to the "freshman 15," which we suppose is the equivalent of dietary grade inflation [source: Khazan]. The truism is still taken so seriously that the news program "Good Morning America" did a 2014 segment titled "Beat the Freshman 15" and offered helpful tips such as, "The dining hall is not an all-you-can-eat steakhouse" [source: Drayer].
However, the "freshman 15" is really a myth. In a 2008 study published in the Journal of American College Health, 121 freshmen at a northeastern university reported an average weight gain of 2.7 pounds (1 kilogram), with men (3.7 pounds) actually gaining more weight than women (1.7 pounds). Only half of the students gained weight at all, and the gains were about 7 pounds on average. A third of the students had no weight gain, and 15 percent actually lost weight during freshman year [source: Mihalopoulos, et al.].
Yes, you'll probably eat more at college than you did in high school (the 3- pound gain is still more than the average person gains in a year), and you should be careful with your diet, but chances are you won't pork up by 15 pounds.