If you’re the parent of a college student, you may be familiar with the “freshman 15”—the 15 lbs. that undergraduates often gain because of late-night study sessions, inadequate sleep and regular snacking. It can be hard to find fresh organic food in a dorm, and many students rely on potato chips, caffeinated colas and fast food to keep them going.

“On average, kids do gain weight [during their freshman year of college], and it’s because of the change in lifestyle,” says Dr. Janet Colson, a registered dietitian and professor of human sciences at Middle Tennessee State University. “Most incoming college students don’t have mom to pick out their foods for them anymore or pack their lunches, and so they start making unwise choices.”

One university study revealed students gain an average of 4 lbs. during the first three months of their freshman year—a weight gain that’s 11 times higher than that for the typical 17- to 18-year-old.

“Accompanying late-night study is late-night eating,” Dr. Colson says. “And what do you do when you’re staying up late? You’re eating and adding calories.”

Complicating matters are all-you-can-eat campus buffets, which challenge one’s sense of portion control. Many students also opt to ride shuttle buses across campus instead of walking to classes.

“We hear students gripe about how far away parking is from campus and all their classes,” Dr. Colson says. “Really, we should be thankful it’s so far away because the exercise is needed.”

Tune in tomorrow for Part 2 of this story, which offers four Freshman 15 solutions.