When Terry Garrison first read the book "Fat Is a Feminist Issue" more than 15 years ago, it was the start of a long process of reevaluation. After years of starving to lose weight and then binging, Garrison decided that her calorie-counting days were over. No longer would she allow her body weight to see-saw between 130 and 205 pounds. She would never be a very thin person, Garrison realized, but she still could be happy and healthy.

Now Garrison is leading a campaign to calm the preoccupations of other diet-obsessed Americans -- fat and thin, male and female. She recently founded the Diet/Weight Liberation Project -- supported by Cornell University's Center for Religious, Ethics and Social Policy -- to encourage people to accept themselves as they are, whatever their shape and size. The project advocates healthy, pleasurable eating instead of harmful, futile dieting, and helps compulsive eaters overcome their addiction to food.

"I want to advocate having a calmer, more sane attitude toward food," says Garrison, 44, who at 5 feet 3 inches and 180 pounds describes herself as "large." "That does not preclude health, fitness or beauty. On the other hand persistent dieting can be a threat to both health and appearance."

Garrison, an alcoholism counselor, runs workshops and publishes a quarterly newsletter based on her dieting experiences and on the research of David Levitsky, a Cornell professor of biopsychology and nutrition, who has been studying obesity for more than 20 years. They are writing a book on diet and weight oppression.

Through his research, Levitsky has found that "size oppression" -- the pressure to be or stay slim -- creates a cycle of obsessive behavior that actually fosters eating disorders such as obesity, bulimia and anorexia. The country's multibillion-dollar weight-loss industry and never-ending media plugs, he says, help keep the diet-obsession/food-addiction cycle spinning at full force.

"How many magazines sell themselves by running diets that promise to make you lose 30 pounds in 30 days or some other nonsense?" Levitsky asks. "These magazines would not sell if they published something closer to the truth -- that a regimen of healthful eating and exercise might lead to a safe, permanent 10-pound weight loss over two years."

Levitsky says that the problem underlying our national preoccupation with dieting is an erroneous understanding of overweight.

"Research has shown over and over again that obese individuals do not eat more than thin people," Levitsky says. "They do not lack discipline, they are not more self-indulgent than your average person. By the same token, if eating too much is not the problem, then eating less is not going to solve it."

Recent studies show that a person's weight is determined by up to 80 percent on genetics.

Dieting is a losing battle for many people because the body is programmed to resist weight loss -- an ability that saw our early ancestors through times of famine. According to Levitsky, some of the body's most effective anti-weight-loss strategies are psychological. As any dieter knows, restricted foot intake leads to an increasing sensitivity to the smell and taste of food. The dieter's thoughts, conversations -- even dreams -- become centered on food. To make matters worse, small amounts of food tend to stimulate the appetite rather than satisfy it. After about a week of a diet regimen of 1,200 calories a day (an average woman consumes 1,800 to 2,000 calories a day, an average man 2,000 to 2,500) the body's rate of metabolism drops; weight loss slows, and irritability and a feeling of constant chilliness ensues. About 30 percent of serious dieters become clinically depressed after four weeks of food restriction, Levitsky says.

When the dieter finally gives in to the constant pressure to eat, he or she ends up gorging, often gaining back the weight that was lost and more.

"The question I want people to ask themselves is," says Levitsky, " 'Why should I struggle so hard to lose weight?' "

Levitsky says that contrary to popular perception, unless you have some other risk factor such as diabetes or high blood pressure, some extra weight is not in itself a health risk.

Yet people get the impression from movies, advertising and television that it is impossible to be healthy, attractive or successful unless you are extremely thin. That, says Garrison, is a myth that grows out of a simple cultural preference for thinness.

Garrison realizes that her campaign has a long way to go in convincing people -- particularly younger people -- to accept their size differences. A recent survey conducted by Levitsky at Cornell University found that 80 to 90 percent of women and 60 to 70 percent of men felt that they should lose some weight.

"I hope I can save some people some of the pain I went through as a heavy teenager and young adult," Garrison says. "I fought so hard and failed to lose weight. In the process I lost the pleasure in normal eating as well as the ability to eat normally."

For those who will listen, Levitsky recommends forgoing dieting and focusing instead on some simple rules for good health. Among these are: lowering fat intake, eating more fiber and participating in some kind of regular physical activity.

"Surprisingly, even without dieting, most people will actually lose about 10 pounds by following these few steps," he says. "And even if they don't they will feel better and keep their weight steady and that's what we should be doing."