The fashion mannequins of America are becoming more voluptuous, their makers swelling their bottoms and chests to keep pace with changing attitudes toward female beauty – and the realities of the average American body.

The mannequins, which have been given names such as Goddess and Sex, have become best sellers in stores from Saks in New York to Chicago’s traditionally plainer Marshall Fields.

The name Jennifer Lopez, the Latina singer and actress who famously took out a special insurance policy on her bottom, is invoked in discussions on the mannequins.

“Open your eyes, and you see this type of body,” said Ralph Pucci, New York’s leading maker of the mannequins. He said that he was also inspired by the supermodel Christy Turlington, who commissioned a curvier version of herself to promote her Yoga Collection of exercise clothes. “She asked me to make a model that showed her as she really was, a woman a little bigger than she was when she was dominating the fashion runways; a woman who is beautiful, elegant, and sexy, and more than just a fantasy,” said Mr. Pucci as he showed off the models in his showroom.

“It’s been in the air, and in my ear, that the untrue size of our mannequins was not reality, and not sexy,” he said.

His mannequins are in demand for lingerie departments – where bigger bottoms boost sales – and for evening wear. Decolletage is as fashionable as it was in the 1950s of Marilyn Monroe and Jane Russell.

Previous mannequins made by Mr. Pucci for stores such as Armani and Gucci have been based on the “runway ideal” of a Kate Moss or a Twiggy: they have vital statistics of about 32A-23-33 and are improbably stretched to a height of 5 feet, 10 inches.

His Goddess model is a more realistic 34B-25-35, and a more buxom 36B mannequin with 38-inch hips is also in the offing.

Mr. Pucci launched Goddess last month and was astounded when 1,000 buyers jammed into his showroom. They snapped up 300 of the mannequins, his largest preproduction order.

Goldsmith Inc., another New York mannequin maker, is enjoying equal success with a model named Sex – described by Ronald Knoth, one of the company’s directors, as “more girlie, hippy, curvaceous.” She made it into the windows of Saks, Macy’s, and Filene’s in time for Christmas.

“Probably more women look like Jennifer Lopez than Sarah Jessica Parker,” said Mr. Knoth.

Mr. Pucci said: “She stands for a shift in the popular culture and it is inspired by hip-hop and the Latina culture in general. You can’t look at a music video or flip through a fashion magazine without seeing this form of sexiness, and mannequins should reflect the times we live in.”

Women’s organizations have given the look a cautious welcome. “This is a very good thing,” said Kim Gandy, the president of the National Organization of Women. “We should not put too much stock in a few shop mannequins, but it is a start, and we should hail every bit of progress.”

Martha Burk, the chairman of the National Council of Women’s Organizations, said: “We’ve long been concerned that the ultra-thin body image of the fashion industry is harmful to women. So on one hand, we are glad that mannequins are getting some meat on their bones – but on the other, it depends where that meat is going, and what the intent is.”

Even in a larger size, the mannequins are slimmer than the women likely to be buying the clothes they display. A “national body” survey conducted recently by the Commerce Department in Washington, D.C., and the Textile/Clothing Technology Corporation, a trade research group, found that the average American woman has grown between 5 and 10 pounds in the past decade and is getting more pear-shaped.

Latinas and white women have hips between 42 and 44 inches, and black woman have hips between 44 and 46 inches.

That, say the women’s organizations, is still a lot larger than the plumpest mannequin or fashion model.

“What we would really like to see is a mannequin that reflects real women – in the United States, that means probably overweight and not very sexy,” said Ms. Burk. “So it is a marketing dilemma; after all, it’s sex that sells.”