Size-zero hero: Fashion's high priestess calls time on 'size zero'

It is the ultimate "size zero" backlash. The editor of Vogue has lambasted the world's top designers for making their clothes too tight for even the skinniest models.

In a letter sent to the biggest names in fashion, from Prada to Chanel, Alexandra Shulman has blamed fashion houses for forcing fashion magazines to find unrealistically tiny models to squeeze into their designs. Photos of models with "no breasts or hips" encourage eating disorders, which affect more than a million people in Britain, campaigners believe.

Her letter to designers from Stella McCartney and John Galliano to Karl Lagerfeld and Alexander McQueen comes as new designers are being urged to "recast the beauty ideal" by designing catwalk clothes that might actually fit real women. For the first time, this autumn's London Fashion Week will feature an event celebrating all shapes and sizes, rather than the "size zeros" that prevail in a typical catwalk show.

The British Fashion Council, which organises the capital's biannual fashion extravaganza, is backing the initiative from Beat, Britain's leading eating disorder charity, which will showcase curvier, older models than the likes of such skinny catwalk superstars as Agyness Deyn and Lily Cole. "It will celebrate and represent a range of body shapes and sizes," said Caroline Rush, the BFC's joint chief executive.

Caryn Franklin, a fashion writer and broadcaster who is working with Beat on the event, said: "It's about expanding the imagery that comes out of LFW so that women can for once see themselves mirrored [in the catwalk photos]."

The supermodel Erin O'Connor, who is deputy chairman of LFW, is also working with Beat on the event. She backed Ms Shulman's call for designers to rethink their sizing, fashion's dark secret that lies at the heart of the "size zero" furore, which has claimed the lives of several models who starved themselves to shoehorn their bodies into tiny catwalk designs. Ms Franklin added: "It's fantastic that Alex, from her position of power and respect, is saying that even Vogue has had enough."

Ms Shulman's letter pointed out that Vogue frequently had to retouch photographs to make models look larger – the opposite of the sort of vanity airbrushing that usually goes on at magazines. It is the first time that a fashion magazine has ever locked horns with designers over their skimpy sizes.

Ms Rush added: "We are pleased that Vogue has chosen to highlight issues of sample sizing and identify their readers' concerns for model health and the photographic representation of fashion."

Although designers claim their samples are sized 8 to 10, fashion insiders admit that these bear no resemblance to anything you might find hanging on the size 8 or 10 hangers at a high street retailer.

Even some of the hottest newer models, such as Daisy Lowe, are too big for most sample sizes.

So far, no designer has responded publicly to the Vogue editor's letter, which was sent at the end of last month. Instead, designers have defended their sizing as "perfectly reasonable", according to Ms Shulman.

But for Beat's LFW event, which will be held at Somerset House in September, designers will have to cut their clothes more generously. Susan Ringwood, chief executive of Beat, said: "We want to encourage the fashion industry to show diversity and to challenge the aesthetic. The beauty ideal needs to be recast. It's not about being very tall or very thin."

It is the first time that the eating disorder charity will be involved with an event at London Fashion Week.