When Joan went home for Thanksgiving last month, she joined in the spirit of the holiday and ate until her skirt was far too snug for comfort and her body was crying out for an afternoon nap. Unlike the rest of her family, however, after consuming a heaping plate of turkey, stuffing, gravy, sweet potatoes, green beans, and hefty chunks of pecan pie and pumpkin pie topped with vanilla ice cream, Joan did not stop.

While she tidied up the kitchen for her family, Joan polished off another plate of turkey swimming in gravy, a pan of stuffing, an entire pecan pie, a gallon of ice cream, and a gallon of milk. Then, cursing her bloated body and lack of will-power, Joan locked herself in the bathroom and vomited up every last bite of her meal.

Joan (not her real name) is a Harvard senior afflicted with a disease that is now epidemic among college students across the country--bulimia. Primarily found among achievement-oriented, obsessive, perfectionist females ranging in age from eight to 50, bulimia--Greek for "ox hunger"--is a disorder that psychiatrists and medical authorities are only beginning to understand; the American Psychiatric Association officially recognized bulimia (or bulimarexia, as it is also known) as a disease just last year.

Unlike anorexia nervosa, whose sufferers think constantly about food yet deny them-selves nourishment while exercising their bodies into a state of abnormal emaciation, bulimia often afflicts women who appear healthy, radiant and at an ideal weight. Despite their differing approaches to weight loss, however, bulimics and anorectics are alike in a number of ways. Their inflated fear of fatness, distortion of true 'body image, and extremely low self-esteem lead them to manipulate their metabolisms and turn an innate self-disgust into a dangerous attack on their own bodies.

LAST SUMMER the employees of the office where Susan worked asked her to get them frozen yogurt when she went on an errand. Knowing that frozen yogurt was her particular dieting downfall, Susan resolved not to have any, until she got to the store and discovered that three of her favorite flavors were in stock.

Suddenly feeling out of control of her eating, Susan ordered a large mixture of the flavors and ate it all, and then went into another yogurt store where she ordered another large frozen concoction and wolfed it down, barely tasting or enjoying the food.

With a mixture of nausea and panic at the number of calories she had just consumed, Susan drove quickly back to her office where she delivered the yogurt to her co-workers, and then went into the bathroom where she made herself throw up.

Susan--a pretty, slender Harvard sophomore--is still plagued with occasional bouts of bulimia, although now she feels more in control of the problem than she ever has in the five years she has been afflicted with it. Like most sufferers of bulimia, Susan has made several attempts to stop gorging/purging--usually after a frightening or disappointing experience with vomiting.

For example, Susan says, "At one point in high school, I was vomiting three or four times a day and I had a big red welt on the back of my hand where my teeth scraped when I put my fingers down my throat. It was then that I started throwing up blood and I got scared about what I was doing to myself."

Susan wasn't scared enough to stop, however, and the destructive behavior continued, although it did not always rid her of her food binge calories. "I vividly remember lying in a heap on my bathroom floor, crying because I just couldn't throw up the five bagels I had eaten," she recalls.

Like the vast majority of sufferers, Susan feels an intense pressure to be thin, smart, career-oriented and successful, and often this pressure has led her to turn to food for comfort. "Being at Harvard just makes the problem worse because everyone is out to succeed here, and people move so fast that they often don't take the time to be friendly or personable. When you feel like the university and the people are impersonal and all there is to do is study and sit around inside, then it is extremely easy to overeat," she says.

Sally, a Harvard freshman who occasionally gulps handfuls of laxatives to cleanse her body of excess calories consumed during food binges, agrees. "I think Harvard is a perfect microcosm for eating disorders," she says. Afflicted with one offshoot of bulimia, Sally shuns forced vomiting ("I hate the idea of hurting myself"), and instead relies on laxative overdoses to combat overeating.

Like many victims of bulimia. Sally learned about laxative abuse through friends who used them, diuretics and diet pills to lose or maintain weight. "I saw laxatives as a way to lose weight easily and painlessly," Sally says. "On days when I took laxatives, I ate whatever I wanted in huge quantities--whatever looked good, and whatever fattening combination of foods I wanted, I would eat."

Like all sufferers of eating disorders, Sally also spends a lot of time thinking about food, and whether she will be able to eat a normal meal without feeling compelled to purge her body immediately afterwards. "There are some mornings when I am lying in bed and I just don't want to get up because I know my eating will be out of control," she says regretfully. "I'll concede defeat at eight O'clock in the morning and think, 'I am a failure for today.'"

JILL CARNI, a recovered anorectic who is a counselor for eating disorders in Cambridge as well as a consultant to various institutions, colleges and mental health facilities, sees a number of Harvard undergraduates, graduate students, and even Harvard employees in her practice. "At Harvard there is a lot of pressure to achieve socially, academically and careere-wise, and for many people food can become the anaesthetic that dulls their mind from the constant grind," she says. Marlene Boskind-White, a New York psychotherapist who deals with eating disorders, places much of the blame for the problem on the high standards the modern women feels she must live up to. "We have to be thin, beautiful, in good health; and on top of that, we have to have career success and be responsible for the children," she says.

Carni says that often the seeds for an eating disorder may be lying dormant in a student who arrives at college and then learns a type of food abuse. "Some girls come to college totally unequipped to deal with sharing a bedroom with a roommate and her boyfriend, and for solace they turn to food," she says. "In large dorms it is extremely easy to learn how to vomit or use laxatives because you see people around you doing it."

Women are not the only people who have eating disorders, Carni notes. Occasionally men who have become hooked on the binge-purge syndrome to make weight allowances for crew, boxing or wresting will seek her help. "It is extremely hard for men to seek counseling because there is such a stigma attached to bulimia," Carni says. "And everyone who comes to me thinks that their problem is the most bizarre and that they are the only people in the world with the disorder. I guess that men think they are the minority of the minority."

JANICE IS a Harvard senior with an eating problem that has caused her weight to fluctuate by as many as 60 pounds in one year. Although attractive and healthy looking now, Janice lives from meal to meal in constant fear that she will either go haywire and overeat, or that she will stop eating altogether and revert to the 96-pound anorexic girl she was six years ago.

"It started out very normally," Janice remembers. "I just wanted to lose about five or ten pounds because my brothers and my dad used to kid me about being fat. I bought one of those exercisers you attach to your door and I became obsessed with it. Sometimes I spent four hours moving my arms and legs in rhythm."

Janice eventually lost more than 30 pounds on a frame that was normal to begin with, and when she hit the 96-pound mark she even thought she could stand to lose a little bit more weight. The months she spent starving herself are almost obliterated from her memory. "I can't remember what I thought, what books I read, what movies I saw--anything," Janice says.

This loss of memory is due to a constant obsession with hunger and food, and is not uncommon, Carni says. "Anorectics have the attention span of three-year-olds. I've treated women who can't sit through a movie, read a book and who are totally insensitive to cold."

Janice's painfully thin frame finally caught the attention to her parents, who ordered her to start eating. "My dad made me sit down and eat a half-gallon of ice cream in front of him," Janice recalls. The pounds piled on, and soon she was much heavier than when she had started dieting. Like some anorectics, Janice then started trying to make herself throw up after food binges. "I drank mustard powder mixed with water because it burns your stomach," she remembers, adding, "Now just the thought of mustard makes me sick," Janice also experimented with laxatives but developed an allergy to the ingredients which left her skin red and blotchy.

Today, food is still an issue of overriding importance in Janice's life, and she says that it affects her emotional stability. "Food definitely affects how I feel--I always think about it," she says. "It's hard to tell if it's cause or effect because it's such a vicious cycle. But I know one thing: I'll always be obsessed with food. It'll never be just a way of staying alive."

MEN AND WOMEN who have never had an eating problem often find it difficult to sympathize with someone who suffers a food disorder. Says one slender Harvard male whose sister throws up several times a day: "When I first found out Mary was throwing up I was struck with disbelief. The whole thing seems so pointless--why eat if you're just going to throw it up?"

"I think it's a glaring weakness in someone's personality if they let food affect them so much," he continues. "I look upon the whole habit as a vice that's just as bad as heroin addiction."

Despite his disgust with his sister's problem, however, Jim brought up the issue with his parents in the hope that a psychiatrist could be contacted by the family. Their reaction, however, was typical of parents who prefer to deny that an eating problem exists until directly confronted with evidence.

"They thought I was crazy," Jim says. "They just said they thought it was great that Mary could eat so much and stay so thin. They just said that she had small bones and that she exercised to much that she was bound to be slender."

Sherry, a Harvard junior, had a similar problem when she talked to her parents about her older sister's habit of gorging and purging in secret. "They got really angry with me and told me to mind my own business," she remembers. "They totally shut their eyes to the situation and didn't deal with it. I suppose it's because if they did admit there was a problem it would be a poor reflection on them as parents."

SUFFERERS OF anorexia and bulimia are not the only victims of eating disorders at Harvard. There is another malady, which Carni characterizes as "the least destructive of them all"--spitting chewed-up food into one's napkin.

People afflicted with this problem often find chewing on "taboo" food to be the only way to stay thin, yet still enjoy the taste of high-calorie foods. After eating a low-calorie meal, "napkinics" will indulge in breads, pies, casseroles, cakes--in short, anything solid that can be chomped on and not swallowed--and then surreptitiously spit the food into a napkin when they think no one is looking. They will then either drop the napkins onto the floor, make frequent trips to the garbage to throw them out, or stuff them into their pockets or purses.

Susan is indignant when she discusses this form of weight control. "The people who do this think that they aren't being noticed, when in fact they're incredibly obvious," she says. "I take it as a direct personal insult that someone would spit their food out in front of me at a meal, as if they don't respect me enough to eat normally. At least laxative abuse and vomiting are things that you do in the privacy of a bathroom."

ALL THE STUDENTS interviewed for this article estimate that eating disorders among Harvard undergraduates are widespread; all guessed that from 75 to 90 percent have an unhealthy relationship with food. Carni, however, estimates that 60 to 65 percent of the Harvard population--including employees, undergrads and graduate students--have a disorder of some sort, and she ironically notes that the largest group of patients she treats are from the Harvard Medical School, where the intense pressures to perform often drive students to compulsive eating habits.

Doctors and researchers who study eating disorders emphasize that the sooner a victim seeks medical help, the more quickly and painlessly he or she can be diagnosed and cured. Carni has found that small groups of about four to six members meeting once a week have been particularly successful in curing gorge-purge behavior. She notes that within seven months of group sessions, women who had been vomiting for five to seven years respectively had resumed eating normally, and that similar sufferers of 11 and 13 years have drastically curtailed their habit. Carni emphasizes, however, that group sessions are not for everyone. The slow, step-by-step recovery can be painful and difficult, bringing problems to the surface which for years have been submerged under an obsession with food.