You can't have your cake and eat it too. And if you're 'Skinny Gurl', a writer for the website Skinny Gossip, you can't eat cake at all.
The frustration engendered by this deprivation has clearly made Skinny Gurl very angry - angry enough to launch a viciously abusive tirade against the gorgeous Kate Upton, an American model with a face and figure that would make most women sob with sheer happiness on looking at themselves naked in the mirror every morning.
Not only that - anyone lucky enough to be dating a Kate Upton lookalike would sob with sheer happiness too every time she got naked. Because Kate Upton - a curvy, sexy, UK size 12 - is the acme of desirability, the woman pretty much anyone - male or female - would choose to have sex with.
Fashion models are another kind of ideal, but certainly not a sexual one. In fact, the female aesthetic exalted by Skinny Gossip - which thinks, believe it or not, that Emma Watson should lose 10-15 pounds - is the diametric opposite of desirability. After all, theories of what cause anorexia and bulimia pivot around the sufferer's wish to starve themselves to the point that their secondary sexual characteristics - bosoms and bottom - disappear, returning them to the figure of a pre-pubescent girl.
Fashion designers, of course, love models with the figures of pre-pubescent girls. But although the rake-thin Kate Moss is a great beauty, she doesn't feature on FMH or GQ's yearly lists of the Sexiest Women Alive. No escort agency advertising online, no prostitutes putting cards in phone boxes, have ever lured in punters by describing women who weigh a hundred pounds with A-cup chests. Quite the reverse. No footballer has ever been caught cheating on his WAG with a Nadia Vodianova lookalike; no footballer, to my knowledge, has ever dated a woman who looks like Keira Knightley or Alexa Chung. The Imogen Thomases, the Abbey Clanceys, with hourglass figures and bones upholstered in plump flesh, are, and have always been, what both men and women have held up as the sexual ne plus ultra.
Of course, there are some people who prefer thin women, and some who like them downright chubby; you don't have to look like Kate Upton to find a partner who thinks you're a knockout. But the ideal she epitomises is of sexual attractiveness, and the words Skinny Gurl uses in her blog post to describe Upton - "well-marbled", "heifer", "lumbering", are so disproportionate to the healthy, gorgeous girl in the photographs that the dissonance is very significant. Skinny Gurl gives herself away as she works herself up into a peak of rage: Upton "looks thick, vulgar, almost pornographic".
There you have it. The skinny ones can't bear the fact that Kate Upton is so sexually attractive. And that's what I find so strange; that's the part about them trying to have their cake and eat it. Because if the skinnies truly are as skinny as they boast, they already, surely, have what they want: they're (by their standards) enviably thin, they fit into sample sizes, they can consider themselves superior to the rest of us. The heroine of my latest novel, Coco, embarks on just such a painful quest, to starve herself down from a UK size 12 (US 8) to a UK 4 (US size zero), because her goal is to become the editor of a fashion magazine, and she thinks she needs to be as thin as possible to achieve it.
But it would never have occurred to me to make Coco's character bitter because other women - ones who still have the curves she's shedding - represent a visible sexuality that she's starving herself to lose! Her journey is painful and unhealthy: to achieve size zero, she has to pretty much live on water and air. I wanted to explore the pressure women in the fashion industry feel to slim themselves down to skin and bone in order to fit into designers' sample sizes. Yet, in all my researches and interviews with women who work in fashion, sexual jealousy towards more conventionally-attractive, curvy girls never came up in all the discussions about the drive to be as thin as possible.
And they never used the kind of aggressive, hateful language spouted by Skinny Gurl and endorsed by the Skinny Gossip website - which is really impossible to understand in any other terms beside jealousy. Because if you're so happy being thin, if nothing tastes as good as skinny feels, if you're so tiny that you can judge the very slim Emma Watson as needing to lose weight, why on earth would Kate Upton's voluptuous, seductive curves bother you in any way? Why would you care?
The only answer is that Skinny Gurl and her cohorts are struggling with a contradiction, with wanting to have it all. With the wish to be model-thin and also sexually desirable. With trying to not just have their cake, but eat it too. Clearly, it's as painful a struggle for them to try to reconcile these two opposites as it was for Coco to waste away to a size zero; and ultimately, as futile. Because trying to achieve something you can never have will always make you phenomenally unhappy. So unhappy that you need to use a blog to try to tear down a happy, healthy, sexy young woman...
Rebecca Chance is the author of DIVAS, BAD GIRLS and BAD SISTERS. Her latest book is KILLER HEELS, out on Thursday 2nd August from Simon and Schuster.