When Crystal Renn was anorexic, her career as a model flourished. She had had heart palpitations. She was so weak that she fainted if she walked too far, and her bones had poked out sharply from under her paper-thin, taut, grey skin. But she was a US size zero – a UK size two – and the work rolled in.

But it was when Renn started eating and expanded to a UK size 16 that her career really took off. In Hungry, her autobiography, described by Nigella Lawson as "a riveting read" and launched on Tuesday at a glittering Manhattan party, the highest-paid plus-size model in America talks of the delicate new dawning of a vogue for women who are "lush and sparkly, with nary a jutting collarbone in sight".

Renn says that while "crazy town still loves to gawp at the ultra-slim" there is a growing appetite in the fashion world for "the natural shapes a woman's body takes when it's not being deprived of food".

She should know. When she was spotted by a modelling agent at the age of 13 she was told to lose five stone: more than 42% of her then body weight. At 14, Renn was smaller than a US size zero and secured a three-year, $250,000 contract and moved to New York.

"When I started modelling in 2002 – and to a slightly lesser degree, today – the look of the moment was nearly skeletal," said Renn. "Starting in the early 1990s with the rise of Kate Moss and of heroin chic, the fashion industry fell in love with depressed-looking, emaciated girls."

The real public relations crisis hit in 2006. In a matter of months models Luisel Ramos and her sister, Eliana, and Ana Carolina Reston and Hila Elmalich died after starving themselves to death in their attempt to be thin.

There was an outcry. The Council of Fashion Designers of America recommended that runway models be aged over 16. Spain banned models weighing less than 8st 11lb from Madrid's Fashion Week. But, said Renn, the immediate change was "nil". "High-fashion models remained as thin as ever," she said.

But now, Renn says, fashion has finally begun – slowly and grudgingly – to change. Inga Eiriksdottir agrees with Renn. She was spotted by the Women Agency in New York when she was 15 and a natural UK size eight. "When I reached 18, I was 5ft 11in and still a size eight, but they wanted a US size 0. It was awful. They pressured me and told me I was fat. I was obsessed with losing weight, but my body just wouldn't do it," she said.

"I did everything: I didn't eat, I exercised, but I couldn't make myself the shape they insisted on. Eventually someone suggested I become a plus-size model.

"It was the best advice of my life," said Eiriksdottir, who is now a natural size 14. "I had no idea it was such a huge market or of the number of opportunities and amazing clients there were for real-sized girls. It's crazy how much work there is. I've worked for Vanity Fair, Bloomingdale's, Saks and Macy's. But what I've really noticed is that the gap is being blurred between standard size models and plus sizes: before there were only super-skinny and pluses, but now you see all sorts of shapes and sizes. All beauty is now being appreciated."

Despite such optimism, the vast majority of couture and prêt-à-porter designers still want to see their clothes worn by skinny models and sold to skinny customers: even designers who have spoken publicly about battling their own weight – Donna Karan, Karl Lagerfeld, Alber Elbaz, Kate and Laura Mulleavy of Rodarte – don't design for plus sizes.

But, said Renn: "Thankfully the pendulum seems to be swinging back, at least a bit," she said. "The 2009 face of Marc by Marc Jacobs is Daisy Lowe, who has a curvier body than has been in style lately. The looks of Jennifer Hudson, Adele and Beyoncé are generally admired, not reviled. "

Within two months of Renn bursting back on to the fashion stage as a size 16, Anna Wintour had asked her to feature in a "Shape edition" of American Vogue.

Wintour chose Steven Meisel, the pinnacle of American fashion photographers, to shoot Renn – and he immediately booked the model to feature in a non-weight-related edition of Italian Vogue.

Renn appeared in Italian Vanity Fair, Italian Elle, CosmoGirl. She is the only plus-size model to appear on a Harper's Bazaar cover and has appeared in four international Vogue editions as well as appearing on the runway for Vena Cava, Heatherette and most notably for Jean-Paul Gaultier in his prêt-à-porter 2006 collection in Paris, for which he personally made her a dress and walked with her down the runway in the show's high-profile finale.

Renn's agent, Gary Dakin, of New York's Ford Models, which represents models who are UK size 12 to 22, says that their novelty use is coming to an end. Instead they will be photographed for one simple reason: because they are beautiful.

"I have been in this business for 11 years and I have seen this debate ripple through the fashion world a number of times," he said. "This time, though, the momentum of the debate feels different." Style arbiter Stephen Bayley agrees. Bayley's book, Women as Design, is published this week and looks at how definitions of female beauty have changed over the centuries. "In periods when we are impoverished, as now, there is a vogue for voluptuous women," he said. "

But designers are, slowly, beginning to agree that larger models have a role. Antonio Berardi has talked of the trouble he has finding girls with a womanly shape. "We have to spend days altering things," he complained. "We add padding and pieces that work inside the clothes to exaggerate their bodies into a more female form. I don't want all those girls with pale skin who look the same. My family is Italian – I am inspired by a womanly aesthetic."

Roland Mouret agrees: "I see advertising going back to that powerful 1980s mentality, when girls like Linda [Evangelista] were ideal. Back in the 80s, when supermodels were several sizes larger than top models today, the clothes worked on bigger bodies," he added. "They were bright, bold, curve-enhancing."

Kate Smith, a size 16 and the highest earner at Hughes Models, said: "The number of plus-size models in the industry has quadrupled in the past few years, but we're still a tiny percentage of the whole modelling business.

"What does my head in is that I'm a model but I can't buy designer clothes that fit me. Everything is crawl-walk-run. We'll get to the point where every shape and size will be represented on the runway, but maybe not in my lifetime."