When did it die? When did our collective disgust at the sickness and sicked-up stomach juices that fuel the fashion industry get replaced by an oh-so-ironic appreciation? When did even most liberals and feminists stop snubbing it and start wrestling their way to the rope-line in search of a goody bag? London Fashion Week starts later this week, a parade of the Emperor's Designer Clothes, made of tinfoil or feathers or rubber. A few years ago, I was sent backstage to cover this event - and it took more than a few London Un-Fashion Weeks of my own to recover from what I saw. I was forced to peer for the first time into the industry that is making so many of my female friends ill.

At the end of the catwalk, there stood a parade of young women who looked like they were about to collapse. On camera, fashion models look worryingly thin. In the (non-)flesh, they look so emaciated that the only other place I have ever seen people like them is reporting on African famines. Their eyes are glazed, shut-down because they have no fuel to run on. These coked-out jangles of gristle and bone were smeared with cosmetics, squeezed into a dress design that appeared to be made of rubbish bags, and pushed out to shimmy down the catwalk, to be applauded by the likes of Kate Moss and Hugh Grant. When they stumbled back, they appeared faint and listless, and leaned against a wall, looking like they needed an IV drip.

The fashion world claims two sets of victims. The first are the women who it uses as models, for a brief window, before discarding them. They are, on average, 25 per cent below a normal, healthy woman's weight. We know how they achieve this, because many former models say so: they starve themselves. They live on water and lettuce for weeks. When they fall below a Body Mass Index of 12 they start to consume their own muscles and tissues. Several models have dropped dead from starvation after success at fashion shows in the past few years.

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But there is a broader circle of victims, far beyond the catwalk's cat-calls. They are ordinary women who are bombarded with these highly manufactured images of "beauty" every day, and react either by feeling repulsive or trying out semi-starvation themselves. A Harvard University study found that 80 per cent of women are unhappy with their bodies, and only one per cent are "completely happy". Men, by contrast, were broadly happy with how they look: the accepted idea of male hotness is so broad it can range from 79-year-old Sean Connery to 20-stone James Corden. We are now living through an epidemic of female anorexia and bulimia, with over 50 million victims in Europe and the US. How many women do you know who are happy with the way they look?

The fashion industry promotes this sick vision coldly and joylessly. The recent documentary The September Issue – following the production of American Vogue magazine's biggest edition of the year – had one great revelation. Anna Wintour – the magazine's editor, and the most powerful woman in fashion – is a brittle, sullen woman who appears to take no pleasure in anything, and only seems to show any vigour when she is being cruel to those around her. Presented with a picture of a stick-thin woman, she announces she "looks pregnant". Presented with a man with a stomach, she reacts with incomprehension, as if fat is a revolting glitch in the human genome. She promotes the use of fur, indifferent to the cruelty to animals it involves. She promotes creepily thin models – is she indifferent to the cruelty to women it involves?

Her depression is infectious: it spreads out through the pages of Vogue. A study by the American Psychological Association found that after three minutes spent looking at a fashion magazine, 70 per cent of women felt "depressed, guilty, and ashamed." Vogue and its ilk are banned in most eating disorder clinics because they know it sends their clients spiralling. The magazine has done real harm to ordinary women. It super-charged the trend for bone-thin models with Twiggy in 1965, and it popularised the bogus idea of "cellulite" in 1973: before then, it was just considered normal female flesh.

But this raises the apparent paradox: if it makes women feel so lousy, why do they buy it? There was a flurry of excitement this summer when Glamour magazine showed a tiny little tummy on the model Lizzie Miller, who was – the shock! – a size 12, still much slimmer than the average size 16. But when fashion magazines consistently show normal women, their sales fall. There is a masochistic impulse among women that draws them to these sick images. What is it?

The best answer lies in The Beauty Myth, the 1991 classic by feminist Naomi Wolf. She argues that it is wrong to believe there is one objective standard of "beauty". No. The Maori think there is nothing more beautiful than a fat vulva. The Padung adore droopy breasts. Obese women were hot here in the 15th century. Our idea of beauty changes depending on how we want women to be.

Wolf points out something remarkable in the shifting tides of the fashion world. Whenever women become stronger in the real world, fashion models – our collective vision of Beauty Incarnate – become weaker and scrawnier. In the 1910s, it was considered beautiful for women to have soft, rounded hips, thighs and bellies: most women's natural shape. In the 1920s, when women got the vote, the idea of what was beautiful shrank. Suddenly models became bonier and feeble – and women started to starve themselves. In the 1950s, when women's rights receded, women could be curvy and eat again. With the 1960s and the rise of feminism, models became smaller and smaller – until today, when women are breaking glass ceilings, and emaciated models are the norm.

Why would this happen? Women were kept down for millennia – and now, in a few generations, there have been incredible strides towards liberation. But the old, patriarchal beliefs are deep in our cultural DNA, for both men and women. Wolf believes women suffer from "guilt and apprehension about our own liberation – latent fears that we may be going too far". This skinniness craze is "a collective reactionary hallucination willed into being by both men and women stunned and disorientated by the rapidity with which gender relations have been transformed". Women have replaced the prison of the kitchen with the prison of an unachievable body shape, as if it doesn't make sense to be a woman without bearing a cruel burden. The more powerful a woman is, the more likely she is to be bulimic.

One day, we will look back on a time when women aspired to be Belsen-thin with the incomprehension we feel for Chinese foot-binding. But how do we get there? This is a problem that lies deep in our subconscious minds, and like all subconscious problems, it has to be dragged to the surface. Wolf says anorexic and bulimic women "are walking question marks pleading with schools, universities, and [the rest of us] to tell them unequivocally: This is intolerable. This is unacceptable. We don't starve women here. We value women."

She's right. We need to start publicly scorning the people who promote sickness in women as if it was cool and glossy and gorgeous. Enough. Women should not be made to feel subconsciously bad about demanding equality; starvation is not the Siamese twin of female success. It requires more of us – men and women – to say: No more. This industry is sick, and stupid, and wrong, and when we see it, we will show our contempt. Can't we have a vogue – and a Vogue – for that?

j.hari@independent.co.uk

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