A generation now believes only thin is beautiful

We have reached the point where only digitally produced images can be as perfect as men, and women, want

One day I may just want to take shelter within the secretive folds of a burqa. At least under that cloak your body can turn, age, loosen up and relax. Maybe this is one reason why so many Muslim women (and droves of white women converts) are choosing the hijab to escape from our awful, oppressive "world of slim". The female body is under such grinding scrutiny – ordered to be ever thinner and tighter, mocked, scorned, rearranged, cut, filled, exposed, starved – and there is no end to it, as the misguided Kate Winslet has just discovered, poor lass. At school she was known as Blubber but she turned into an irresistible young actress with a beautiful, expressive face and a softly feminine body.

Then came a baby, more success, and the pressure was on: Winslet had to shed her pounds on the orders of Hollywood. She despises these injunctions: "All the men I've ever spoken to say they like a girl to have an arse on them, so why is it that women think they have to be thin, very thin?"

But she obeys Hollywood's injunctions nevertheless. She got thin, very thin, and told us all (yawn, yawn) about her wonderful diet of buttered potatoes. Yet for GQ magazine, the thinking man's strumpet, her svelte form was still too corpulent. So they doctored her pictures admits Dylan Jones, the editor: "Various parts have been improved [sic], including her stomach and legs" – a common practice apparently. Sophie Dahl too had to become very thin and even then they digitally drained more fat and blood out of her before showing her in a post-orgasmic trance on posters.

We have reached the point where only digitally produced images of perfection can be as perfect as male aesthetes want women to be. And women collude in this, says Felipe Fernandez-Armesto, the author of Food: A History: "anti-fat propaganda is not gender-specific; female fashion editors and designers connive in its campaigns, and feminism has contributed to the hallowing of women's own bodily 'control', of which dieting is an aspect."

What next for Kate then? Does she look at herself in the mirror now with shame? That is the point of course: to make her and the rest of us believe that we are worthless gluttons. It is why the rare big birds, such as the morning-television presenter Fern Britton and the comedian Dawn French, are so adored by their public. They have guts.

The rest of us are not that strong. In January, the month designated by our media-wallahs for self-flagellation, self-disgust, self-deception and impossible forms of self-control, this message has been emitted ad nauseam. A sceptic, I somehow now know about the Pritikin and Zone diets, the Fat Flush Plan, the slimming pill Xenadrine, Jane Scrivner's Detox. Oh yes, and I confess that I am thinking, if not the burqa, then maybe the tummy tuck.

They claim they are concerned about obesity and the terrible health problems that can result from this. This is a pernicious cover-up for their real intentions. It gives their obsessions a respectable face, another excuse to push their body fascism into every cell of our lives and those of our children. Winslet and Dahl were not obese but they were treated as though they were. Thousands of children and young people are not obese in any sense of the word and yet if they are not skinny, they are not only teased (which has always gone on) but panicked into thinking that soon they will be immobilised by fat and become fatally ill.

Worse, they know they are "disgusting", a blot on our lovely landscape which should only have Kylie or Dannii floating across it. Tonight on Channel 4, the programme Skinny Kids shows how this is damaging to all children. Six-year-olds already hate their legs and tummies and want special medicines to keep them thin. Nine-year-olds talk like dissatisfied old bags.

Adults too suffer devastating low esteem brought on by any weight gain or continuous failures of endless diets: 88 per cent of British women have dieted; the majority of us hate parts of our bodies. Jobs and promotion are more easily given to slim enough people; most outspoken feminists are determinedly thin, perhaps because they never want to be accused of being like Andrea Dworkin.

Besides asylum-seekers, plump and fat people are the only other group in our society we are allowed to bully, reject and openly abuse. In a John Lewis shop before Christmas I saw a woman drop an expensive vase as she was bending to pick it up. It broke. I could see her hands were shaking involuntarily, as if she might have Parkinson's disease, but she was overweight and people quickly started expressing their contempt that she "had allowed herself to get so fat". She burst into tears and shuffled off. People such as her are now placed outside our moral universe, and that is what is truly disgusting. We blame them for being, and that is the worst discrimination of all.

The British Heart Foundation claims that two thirds of the men and half the women in Britain are overweight, but what does this mean? Does it include me, probably 10 pounds above what I was in my twenties? If so, I reject these figures. According to Ellen Rupell Shell, whose book The Hungry Gene comes out soon, 1 billion adults in the world are clinically obese. Young obesity is up 70 per cent since the Eighties. These are serious statistics. But being not thin is not the same thing. The NSPCC once produced figures showing absurdly high levels of child abuse by including actions which were harmless, thereby devaluing the damage. Obesity is a serious problem, but being a size 12 or 14 shouldn't be. And we are giving out dangerously mixed messages. Are we worried that people are fixated on diets or that too many are overweight? Is the persistent bulimic saner than the incurable flabby?

I also think there needs to be better scientific explanations about body size and food. Some people do eat too much, or the wrong foods and, yes, they could change their eating habits. But some plump people I know eat very little. It is iniquitous to accuse this group of indulgence. Developments in science are already giving us clues that there may be genetic differences between the naturally thin and the plump. An American doctor, Nikhil Dhurandhar, believes that a virus is causing the epidemic in obesity.

We criticise food manufacturers, yet free-market governments do not stop the ruthless advertising of sweets and other bad food to children. And why are the poor getting fat while the rich get thinner year on year? Could it be that the poor are making their own (and maybe even valuable) protest against the terrifying Trinnies who dictate how we may look? Or maybe we turn into over-eaters because the standards of what is normal are now so impossible that it hardly seems worth the bother?

Everything is distorted by the slim culture. I love Rembrandt's Danae – a young woman who, as Simon Schama says, is "bathed in golden light, her breasts, belly and thighs turned hospitably to the beholder". But like another of Rembrandt's women, Bathsheba, Danae has folds and soft flesh. I was showing these to some teenagers when I went to speak to them about the painter. "Ugh" they all said.

Some of the loveliest images in the world are now only "gross" for a generation made to believe that a woman is only beautiful if she is desperately thin and fading fast. How terribly sad.

y.alibhai-brown@independent.co.uk