This is not simply a pro-fat movement, or a throwing in of the collective towel when it comes to weight control. In fact, weight experts point to signs that a weakening obsession with skinniness can lead to a stronger attraction to fitness. Curves (formerly called Curves for Women) fitness centers, which are more welcoming to larger women than the average gym, are the fastest-growing franchise in America, according to Entrepreneur magazine. Over the last seven years, the number of locations has grown to more than 5,500, while a new one opens every four hours, said Gary Heavin, the chief executive and a co-founder of the company, which is based in Waco, Tex. Until January, Curves did not advertise.
''Most gyms are more akin to nightclubs than they are to support groups or exercise centers,'' Mr. Heavin said. ''Women felt they needed to lose 10 pounds before joining.''
Curves centers are relatively small -- they fit easily into a modest strip mall or neighborhood storefront -- and offer a half-hour workout designed for women unaccustomed to exercise. A large part of the appeal, Mr. Heavin said, is that average or heavier-than-average women can get together with like-size women to support and inspire one another.
The phenomenal success of Curves, many experts say, is a sign that women are accepting, and therefore taking better care of, their bodies.
WOMEN are also writing more letters to magazine editors, criticizing the spindly fashion models and praising efforts to include bigger women, said Cindi Leive, the editor in chief of Glamour. She has received thousands of responses to her second annual ''body love'' issue in May. ''It's now a mainstream idea that no one should be allowed to tell us that we need to diet in order to have worth in this world,'' Ms. Leive said, ''and it wasn't 10 years ago.''
Emme, perhaps the most famous of the full-figured fashion models, has been lecturing at college campuses and even testified before a Congressional subcommittee about the need to help women overcome their problems with body image.
''What I stand for is accepting your body type, whether you are a size 2 or a size 14, and then taking care of yourself with a balance of exercise and eating really well,'' said Emme, who introduced her own line of women's clothing sizes 14 to 24 last fall.
Another popular full-figured model is Mia Tyler, the focus of several Web sites. Ms. Tyler, a half-sister of the actress Liv Tyler, has modeled for Lane Bryant and H & M's Big Is Beautiful line.
But will this new awareness be enough to cure the plague of body hating that, mental health experts contend, is widely and deeply ingrained in American women?
That may be too much to ask.
''If there's a change so far, it may be that women have gone from being horribly dissatisfied with their own bodies to being somewhat less horribly dissatisfied,'' said Dr. Kelly D. Brownell, the director of the Yale Center for Eating and Weight Disorders, and the author of the Barbie proportions study. ''It's very hard to find a woman who really likes her body. Even if she likes the shape, she will not like her toes, her knees, her elbows or her ankles. There's always something wrong.''
Prof. Susie Orbach, a sociologist at the London School of Economics and Political Science, has been addressing the subject since 1978, when her book, ''Fat Is a Feminist Issue,'' was first published. ''I think there could be a zeitgeist change, but there hasn't been yet,'' she said. ''We're still not fully recognizing that the body-image problem is a public health emergency.''
Body dissatisfaction, Dr. Brownell said, stems from two assumptions -- that a body can be shaped at will, so that ''the only thing that lies between any woman and perfection is effort,'' and that an imperfect body reflects an imperfect person. ''Superimposed on these wrong assumptions is the highly unrealistic body ideal,'' he said. ''It leads women into conflict with their own body.''
The conflict can play a role in eating disorders like anorexia nervosa (chronic undereating), bulimia (overeating followed by purging) or chronic binge eating but, psychiatrists say, they are too complicated to be explained by body dissatisfaction alone. Full-blown eating disorders are rare. But even for a woman not suffering a full-blown eating disorder, disappointment with the size or shape of her body can be a daily problem. A recent study at the University of Central Florida, in Orlando, showed that adult women who have a positive view of their bodies are happier no matter what their age is.
The trouble is, most women do not have a positive view of their bodies, experts say.
''It's a subclinical pathology that is so ubiquitous, women think of it as a normal obsession to have,'' Professor Orbach said.
At this point, even if movies, television and magazines all suddenly started promoting images of normal-size or large women, the skinny-body ideal would persist, Professor Orbach said, because it is so embedded in the average woman's psyche. The notion that a woman should be rail thin, she and others said, is transmitted from one generation to the next.
''We're in our third generation now,'' Dr. Burgard said. ''I have patients now whose grandmothers were anorexic.''
About a third of American women are obese, meaning that their body mass index -- a ratio of weight to height -- is 30 or more. Another third are overweight, with a body mass index between 25 and 29.9 (under 25 is considered healthy). The average 152.3-pound American woman who is just under 5 feet 4 inches will have an index of 27, overweight but not obese.
A woman whose body mass index climbs above 25 or, more dangerously, past 30, stands an increasing risk of developing diabetes, high blood pressure, heart disease, osteoarthritis, sleep apnea and various kinds of cancer -- like breast, colon and endometrial cancer. Excess fat strains the body's metabolism and the skeleton, leading to insulin resistance, plaque buildup in the arteries and other problems.
THE fact that widespread negative body image coexists with the growing weight problem is ''no accident,'' Professor Orbach said. The ''narrow aesthetic,'' she added, that is promoted in popular culture leads women into a vicious cycle of overeating. ''They think they should deny themselves food, and then they eat more than they want,'' she said, ''and then they feel terrible so they eat too much again, and they don't know how to solve that problem, so they eat more.''
Black women, many studies show, are less likely than white women to hate their size, but that gap is shrinking, experts say.
Dr. Kumea Shorter-Gooden, a psychologist at the California School of Professional Psychology in Alhambra, and a co-author of a book called ''Shifting: The Double Lives of Black Women in America,'' to be published in September, recently interviewed hundreds of black women, partly about their view of themselves. ''African-American women are more comfortable with being overweight than Anglo women are, and African-American women are in general heavier than white women,'' she said. Black culture, she said, does not encourage thinness as extremely as white culture does.
But increasing numbers of African-American women are engaging in such destructive eating-related behaviors as starvation diets, vomiting and using laxatives, Dr. Shorter-Gooden said.
Body-image problems have begun to affect a wider range of age groups -- girls as young as 10 and women in their 50's and older -- psychologists have found.
Another disturbing trend in body image, Ms. Leive said, is the soaring popularity of plastic surgery. ''You're hard pressed to find a Hollywood actress who hasn't either had work done or has spent the last six months nibbling on crumbs,'' she said.
What can be done? Women, Dr. Brownell said, must ''uncouple their body esteem from their basic self-esteem,'' and realize how destructive these unrealistic ideals can be.
Society, he said, must learn to appreciate a greater variation in body shapes and sizes. ''We accept variations in hair color, eye color and facial features, and we should do that with body weights,'' he said.
''Size acceptance is really important,'' Dr. Burgard agreed. ''I don't see how we're going to stop eating disorders until we stop reading character into the size of people's bodies. It's stereotyping. We've made progress against other stereotypes, and we can make progress against this one, too.''
