As chance would have it, New York Fashion Week starts tomorrow and for a moment last week, it did look as if something might bring about a healthy change to an industry that has proven remarkably resistant to previous efforts. But this has nothing to do with a model showing some tummy fat.

That particular photo, posed for in an American fashion magazine, has been exhaustively discussed everywhere, from the Guardian to GMTV. According to one hyperbolic newspaper headline, it might even "blow fashion apart" and, according to another, "start a catwalk revolution."

Dear readers, I can exclusively reveal to you that this will not happen – not this week, not ever. I don't care how many times the same two models get wheeled out to say that Jean-Paul Gaultier loves their bounteous cleavage (well, he let them appear in a show, once, possibly just after the transvestite model), the fashion industry is not interested in making women feel better about themselves. Fashion is about making people want something they are unlikely to get, whether it be a flat stomach or a £5,000 Fendi coat, and any satisfaction achieved is fleeting and faintly disappointing. 'Tis not for naught that the fashion world's usual drug of choice is cocaine.

Yes, fashion's obsession with thinness is sick. But I'd like to talk about something else.

Last week, just as Lorraine Kelly was cooing over the "pioneering" photo, a fashion designer in Los Angeles was notching up a different kind of first.

Anand Jon Alexander, known professionally as Anand Jon, has achieved a certain kind of success since moving to America from India: his clothes have been worn by Paris Hilton, he has appeared on America's Next Top Model.

Then, last week, he was sentenced to 59 years in prison, having been found guilty of 16 counts, including sexual battery and performing lewd acts on a child. In other words, Alexander, 35, had for many, many years been raping models who worked for him, some of whom were only 14 at the time. These 16 counts only relate to charges in California – he is still awaiting similar charges in Texas and New York.

Yet this was barely reported in the UK, and even the US coverage was pretty limited, certainly compared to that of the PR stunt of the model showing her tummy.

Even more than eating disorders, the fashion industry's real dirty secret is the sexual abuse of models, male and female, and last week when I spoke to models and editors about the Alexander case, the only surprise they expressed was not at what he had done, but that the models had come forward at all. This rare conviction going almost unnoticed is a missed opportunity of literally criminal proportions. One picture of a normal-sized model is commendable, but it will not effect any real change. Widespread coverage of the Alexander case, however, could have forced the industry to at least acknowledge this issue. Instead, it has been brushed aside.

It is impossible to say how common assaults on models by people in the business are because so few are reported, partly for the usual reason assaults often go unreported (a sense of shame on the woman's part), but also because of some factors specific to the fashion industry: models are often very young; they fear they won't work again if they "cause a fuss". Model Cohen describes it as "a reality in the industry".

"I know a model who, when she was 16, went to Paris on a photoshoot with a very famous photographer and he sexually assaulted her. She was stunned but didn't say anything," says Sara Ziff, a model in New York. When Ziff herself was 15, she had to explain to a photographer that she wasn't interested, "and I was lucky in that he was fine about it." Also, she points out, fashion is a very small industry in that "all the important people know each other, and look out for each other." Or, in other words, cover for each other.

Katie W, a model, testified that Alexander had contacted her via a website ("I was really excited when I got the email," she told the court) and, after personally assuring her mother that he would look after her, invited her to meet him. "He said, 'If you're going to be a fashion model in runway shows, you know, they get naked backstage. You gotta be comfortable being naked.' It made sense at the time." And then he raped her.

There have been efforts to change this. Ziff recently made a film, Picture Me, about this problem in the industry. In this country, Victoria Keon-Cohen and her fellow model Dunja Knezevic, have established the first union for models, protecting its members against these kinds of abuses. Erin O'Connor has been similarly proactive helping younger colleagues. The fact that all these efforts have come from models as opposed to the outside media (which gets too distracted with painting models as evil fem-bots and harbingers of eating disorders to see them as underpaid homesick teenagers), suggests maybe people find the idea of models making them feel fat more upsetting than the very real fact of models being raped.

This is not to diminish the weirdness of fashion's fetishisation of thinness – just a suggestion there are other problems worthy of attention, too.

Fashion is often accused, rightly, of being obsessed with surfaces. But last week it was everyone else who was too busy ogling a model's tummy to look beneath the depths and beyond the PR stunts. Just because you can see a model's fat roll, doesn't mean the image hasn't been airbrushed.