It has featured naked women on the cover and even actresses without makeup. But now a leading fashion magazine has created a real shock for France's fashionistas by tackling the last taboo: plus-size models.

The latest edition of French Elle is arriving on newsstands this weekend with a picture of model Tara Lynn wearing a white jumpsuit on the cover. Lynn is a plus-size model who sports, it says, "adorable belly fat" and inside appears with three other larger models for 32 pages of a "special edition" dedicated to plus-size fashion.

It comes a month after Italian Vogue launched an online section called "Vogue Curvy" dedicated to fashion and beauty for larger women. In January US glossy magazine V ran a plus-size-themed edition featuring Lynn and other models under the headline "Curves ahead". And last September the issue was again in the spotlight after British designer Mark Fast's London show caused a storm when his stylist allegedly walked out over a decision to use larger models.

Some see French Elle's decision to challenge the national stereotype of slender, chic Parisian women as breaking down the last bastion of a super-slim aesthetic that has gripped the fashion world. However, many doubt that the French will ever accept a larger body as an acceptable look and several fashion insiders told the Observer that the French Elle shoot was simply a "gimmick", not a trend.

Others disagree. Velvet d'Amour, a US model who lives in Paris, has conquered both fashion and TV at size 28. She has been a catwalk model for Gaultier and Galliano and is now a popular TV commentator.

Shops and websites for larger women are becoming highly visible. Parisian fashion writer Sakina, whose blog Saks and the City is widely read, told the Observer that the Elle cover was a "wonderful initiative".

"It's almost unbelievable to see such a huge magazine cover a real plus-size woman. Along with Vogue dedicating a section to curvy women, it's the most shaking news I've seen," she said.

"Fashion has created a gap between itself and real women. From skinny, to curvy, to fat, the population is made of very different bodies and the contrast between the women represented in fashion or advertising has been so important that most women don't feel good about themselves. I, too, have had body issues: I tried to fight what I genetically am because I always thought that being beautiful could never mean being curvy."

She added: "The fashion industry is evolving, but slowly. Elle is considered as a magazine that steps out for women, so I want to believe this is not only a one-off. The famously Parisian chic is a fashion spirit, certainly not a weight or a body shape."

Although far behind the US and the UK, the French are getting significantly bigger. Statistics show that 42% of French women are now classified as overweight or obese, while more than half the male population – 51% of French men – are officially overweight or obese.

But one Parisian fashion industry insider, who did not want to be named, said French Elle was acting less out of desire for change than "to respond to the criticisms directed at them for showing only thin models".

He told the Observer: "It's a gimmick. Having one edition that you fill with big girls is like world women's day: one day a year is reserved for them and the rest of the time you go back to normal."

The capital's fashion elite was far from changing its mind about bigger models, added the insider. "You know why? Because clothes don't look as good on bigger people."

Size is now a hugely contentious issue across the developed world. This month a row erupted in Australia when designer Rosemary Masic said she would cap her clothes range at size 14, as anything bigger "endorses an unhealthy lifestyle". "I am very passionate about life and serious about health," said Masic. "Size 16 and size 18 are not healthy sizes to be." But she was criticised for stocking clothes at the other end of the spectrum, size 6, which some see as equally unhealthy. The German magazine Brigitte this year said it would no longer hire professional models because staff were tired of retouching photographs of bone-thin models to make them look bigger.

German designer Karl Lagerfeld, 76, who attacked chainstore H&M for producing his designs in all sizes instead of just for the "slim and slender", stepped into the row, saying what many in fashion believe – that no one wants to watch larger catwalk models.

"Fat mummies sit there in front of the television with their chip packets and say skinny models are ugly," Lagerfeld told Focus magazine. He said fashion was about "dreams and illusions", not reality. Critics, however, say it is also about eating disorders and pressured young women, but he is not alone in that view.

Others feel Elle has dragged behind the curve. Glamour magazine published a small photograph of model Lizzie Miller, showing a natural-looking stomach, last September. A deluge of responses declaring it "the most amazing photograph I've ever seen in any women's magazine" led the magazine to commission Dutch fashion photographer Matthias Vriens-McGrath to shoot plus-size models Miller, Crystal Renn and Kate Dillon, among others, in a style similar to that made famous by US photographer Herb Ritts with nude supermodels in the 1980s.

This month designer Michael Kors, US Vogue editor-in-chief Anna Wintour and model Natalia Vodianova were at a Harvard forum to discuss changing body types in fashion. Vodianova talked about her postnatal anorexia, and Kors called waif-like models an "army of children" and announced he would no longer book models aged under 16.

"The fashion industry is starting to address real women again," Kors said. "The emphasis in fashion is shifting toward an emphasis on real women who are women, not girls.''

If the fashion magazines do not lose readers by using a diversity of models in all shapes and sizes, then the designers could find that change makes commercial sense, even if some steadfastly refuse to accept the aesthetics.