SUNDAY, April 6 (HealthDay News) -- Looks like the infamous "Freshman 15" is more realistically the "Freshman 5."

A new study of 36 freshmen at Auburn University in Alabama found an average gain of 1.9 pounds during the first semester of the first year at college and an average gain of 4.8 pounds for the entire year. Men gained an average of 5.4 pounds, and women gained an average of 3.2 pounds.

Alabama has the third-highest rate of adult obesity in the country (29.4 percent) and the 11th-highest rate of overweight youth (16.7), according to the latest report from Trust for America's Health.

Although the students surveyed gained (or even lost) a wide variety of poundage, some of the kids who got heavier actually switched from a normal, healthy body-mass index (BMI) into the overweight category, said study author Sareen Gropper, graduate program director in the department of nutrition and food science at Auburn University, while others "graduated" from overweight to obese.

"For some, there needs to be intervention," Gropper stressed.

"It's a cautionary tale. It was such a small study, but it does open up the notion that post-adolescence kids, when they're left to their own devices, do gain weight," said Arlene Spark, director of nutrition at Hunter College in New York City.

Despite the legend surrounding the Freshman 15, there is surprisingly little scientific data on the phenomenon, stated the authors, who were expected to present their findings Sunday at the Experimental Biology 2008 meeting in San Diego. The presentation is part of the scientific program of the American Society for Nutrition.

Previous research found that college freshman had an average weight increase of 2.7 pounds over the year, with men reporting an average gain of 3.7 pounds and women reporting an average gain of 1.7 pounds. In that study, only 5 percent of participants reported gaining 15 pounds.

Some previous research had indicated that 15 pounds may have grossly overstated the weight gained during freshman year.

In this study, about three-quarters of the 26 females and 10 males gained weight during their first year of college, ranging from a loss of 5.8 pounds to an increase of 13 pounds. Twenty-one percent gained five pounds or more.

The mean initial weight of females was 124.9 pounds, which increased to 126.9 pounds after the first semester; mean BMI rose from 21 to 21.4.

Why the overall gain?

Gropper and her colleagues are in the process of investigating the reasons in a larger sample of students but have some ideas.

"We're speculating it's a variety of factors," she said. "For some kids, it's decreases in physical activity, and it may have to do with all-you-can-eat dining halls. Some kids say 'I can go there six times a day and eat for free.' A lot of kids are also eating out tremendously and eating junk food after 10 [p.m.]."

"When you put someone on a cafeteria diet, three times a day, seven days a week, it's like being on a cruise. You have unlimited food, and it's very difficult to moderate," Spark added. "When we give rats Purina rat chow, which is very boring, they eat as much as they need, and they stop. But if you give the same rats frosted flakes and fatty foods, stuff that's really tasty, they get very heavy just like we do. We do have an animal model for this. It's worth reminding people that all-you-can-eat is very challenging for us, and sometimes, it's regarded as an obesogenic environment."

And answers to the questionnaire participants were asked to fill out also shed some light on the subject. When told what one serving equaled in baked goods, snack foods and sugar-sweetened beverages, some of the students responded, "Oh, my gosh!"

"They have this realization," Gropper said.

More information

The American Dietetic Association has more on healthy eating.

SOURCES: Sareen Gropper, Ph.D., R.D., L.D., professor and graduate program director, department of nutrition and food science, Auburn University, Auburn, Ala.; Arlene Spark, Ed.D., director, nutrition, Hunter College, New York City; April 6, 2008, presentation, Experimental Biology Meeting, San Diego

Copyright © 2008 ScoutNews, LLC. All rights reserved.