At Harvard and other competitive schools, disturbed eating patterns are almost an accepted part of college life.

"It's a college-bound sort of thing--it has to do with the environment: the competition, issues of the dating scene, controlling your eating for the first time, dealing with the stress of exams," Heatherton says. "Some of the behaviors are almost normative, [even] expected. It's more like crowd behavior."

Heatherton's survey found problems with food and exercise are widespread among Harvard students.

According to his study, 32 percent of Harvard women believe that they are overweight and 80 percent want to lose weight. Twenty-four percent of women and four percent of men say they have used starvation fasting as a method of weight control some time during college.

Eighteen percent of the women who responded to Heatherton's survey were binge eating at the time, while five percent of women and one percent of men said they vomit to get rid of unwanted calories.

Thirteen percent of women and five percent of men identified themselves as compulsive overexercisers, and 45.7 percent of women and nine percent of men reported that they dieted sometimes, usually or always.

Many of these respondents, who are likely not suffering from full-blown clinical disorders, still have cause for concern, Heatherton says. If eating is causing anxiety, there is a problem, he says.

"If someone is extremely worried about [eating] then that's a problem...if the eating behavior is really interfering with their lives," he says. "It doesn't have to be a clinical thing. A person doesn't have to be emaciated to seek help. They just have to feel its not going the way they'd like it to be."

Students say anxiety about eating is commonplace on campus. One undergraduate says her roommate has never been diagnosed as anorexic, but looks far too thin.

"Sometimes at a meal together I'll notice she's taken a lot of food, made a mess of her tray, peeled an orange, but she hasn't really eaten anything," she says.

Many students start to focus obsessively on calories and weight gain.

Sara, a sophomore at Harvard, says she doesn't "binge or purge or starve" herself, but still "thinks about food way too much."

Even a routine trip to the dining hall can cause fear and guilt for Sara, who says she also feels guilty if she doesn't exercise every day.

"I don't usually eat cheese, I don't eat butter on bread, I don't ever eat ice cream," the sophomore says. "Most of my girlfriends are the same way, so I don't feel like it's a weird thing."

The stress of the Harvard atmosphere may augment students' feelings of inadequacy. Dieting can become contagious, as friends evaluate one another's eating choices.

One sophomore, Lena, feels women compete with each other in the dining hall.