There may be one more way for young women to avoid dreaded college weight gain — and without any effort on their part.

Contrary to conventional wisdom, having an overweight college roommate may lead to less than average weight gain and more conscious health decisions.

A new study by U. Michigan found that college women who are randomly paired with roommates who weigh more than average gain less weight than women with trimmer roommates.

The study showed that these women gained only half a pound. Typical freshman weight gain is between two and a half to six pounds — substantially less than the “freshman 15.”

The study, which was released Sept. 21, explained that heavier roommates are more likely than average-weight women to diet.

Exercising more often and being more likely to use weight loss supplements and purchase college meal plans with limited access to food were among the reasons for the difference in weight gain.

There have been previous studies done suggesting that having an obese spouse, friend or sibling increases the likelihood of becoming obese. However, unlike roommate pairings, these relationships are not random.

Researchers assessed 144 female college students randomly assigned to share living quarters during their first year. At the start of the fall semester, the researchers noted the women’s height and weight and asked about weight management behaviors.

These behaviors included things like whether they had tried to lose weight in the previous year, the average number of times per week they exercised and whether they had signed up for an unlimited college meal plan.

U. Minnesota freshman Kelly O’Neill agreed with the logic behind the study but isn’t worried about gaining weight during her first year of school.

“I haven’t gained weight so far, so I’m not concerned,” O’Neill said.

A 2009 Boynton Health Service study found that more than 40 percent of all females had a body mass index that placed them in the overweight or obese categories.