Amy Jenkins: We can't help ourselves: our love affair with skinny just goes on

In a brief interview with Women's Wear Daily, Kate Moss talks repeatedly about making jam.

When asked how she channels her creativity, she replies that she makes jam. When asked how she relaxes, making jam comes up again. What she does with all this jam is anyone's guess because in answer to the question "Do you have a motto?" she quotes the anorexic mantra: Nothing tastes as good as skinny feels. Then adds: "You try to remember, but it never works." Perhaps that's because the deliciousness of home-made jam – to take just one example – derives not just from its flavour and texture, but also from nostalgia, tradition, ritual and a sense of nourishing homely comfort. So – clearly – some tastes give rise to feelings easily good enough to rival that being skinny thing.

Somehow I don't think Moss's heart was in her motto. She's never been one for bothering us with her weight loss tips, or what she had for breakfast. My guess is she's just naturally small – probably doesn't even think about food that much. It seems more likely that she wasn't paying attention to the interview in general. (When she was asked what inspired her, she answered: "Films and books... and music" and that was it.)

But of course, the skinny motto she quoted was very un-PC and Kate has been duly slammed in the press. The Sun called her a "shocker" and Denise Van Outen said: "Kate Moss is talking out of her size-zero backside."

So the done thing is to be up in arms, although it's pointless, of course. The press does nothing but encourage girls to be skinny – even if this encouragement is covert (sort of). The reality is skinny women are lauded, "curvy" women are shamed. That's what sells. We, the public, buy it. The thing is, we know it's wrong, but we love thin. Boy, do we love it. Our love affair with skinny just goes on and on.

I'm a failed anorexic myself; just never had the willpower to succeed. When I was younger, I used to sometimes wish I'd the guts to put my fingers down my throat. Which admission is enough to make anyone sane throw up. And yes, I know, anorexia is a serious, sometimes fatal, disease and I've witnessed it at close quarters so I know the reality is far from glamorous. And yet these crazy thoughts have crossed my mind – such is the pressure to be thin.

I remember my early indoctrination. I was first introduced to one of these self-improving body conscious mottos when I was seven years old. A friend's mum showed us how to throw back our elbows vigorously while intoning: "I must, I must, I must increase my bust." Then, when I was a teenager it was: "A moment on the lips, a lifetime on the hips." Quite catchy, really. It still sometimes runs through my head when I bite into a piece of cheese.

Not surprising, then, that so many women obsess about food. Though not all, of course. I think there are two types of thin: the lucky ones who don't have to try (like Kate Moss) and the ones who have to put loads of work into it (like Madonna). When I'm with my friends who are in the first category, I just pretend to be normal. When I'm with my friends in the second category we fall guiltily, but happily, into deeply rewarding conversations about the calorie battle.

A battle made all the harder now live in a world that delivers temptation at every turn. When I was a child the most exciting ice cream available was an uninviting rectangular slab made by Wall's. It was called raspberry ripple and it was livened up with pork fat rather than double cream. Now there's double-choc-chip-luxury-taste-the-difference-indulge-yourself-organic-supreme-deluxe everything – on every street corner, it seems.

The more food there is, the more it's a status symbol to be thin. In the days of Rubenesque women in the 1600s it was OK to be large because that meant you were rich enough to eat copious meals. Now that everyone's got enough to eat – and now that the masses are getting fatter by the minute – there's status in being thin. And that's a powerful thing.

Status is one of our evolutionary drivers and, as the psychologist Paul Gilbert points out in his groundbreaking book The Compassionate Mind, published this year, evolutionary imperatives fill us with thoughts, feelings and desires that we're not particularly in control of. Humans have survived so spectacularly well because we have adapted to living in groups and that has meant we've evolved to believe passionately in hierarchies. The desire for status and inclination to submit to the status of others are all part of our ability to live in groups.

Gilbert's unique contribution, however, is to implore us to be compassionate with ourselves about all of this. Our "old" evolutionary minds will pull us in ways that our more sophisticated evolved minds may find difficult to accept. Hence the dichotomy in the press, where we're told what's PC (curvier figures) but we're sold what excites us (Cheryl Cole in hot pants).

You might call it spite. I call it people power

Katie Price is threatening to leave I'm a Celebrity... Get Me Out of Here! if she's continually put to harrowing bushtucker trials by the public. Her brother Danny has likened the ordeal to a public stoning. "It's like the gladiators," he said, accusing the public of "taking out their spite on her".

Is it spite? Or is it just more evidence that the public is getting more and more canny about using its power in these phone-in reality shows. It all started in 2006 when Endemol put a fake celebrity into Big Brother and the public voted for her to win. Then there was the famous John Sergeant Strictly Come Dancing debacle, two years later. The elderly journalist was likeable but a terrible dancer. He was forced to retire from the show when the public threatened to make a nonsense of what is essentially a dancing contest by voting for him to win.

Similarly on The X Factor, the terrible twins, John and Edward Grimes, are currently being supported by the public despite an apparent inability to sing. Simon Cowell made things worse by saying he'd leave the country if Jedward won. The votes rained in. He's since changed his mind, of course – and even refused to expel them when he had the chance. Presumably he realised, somewhat belatedly, that they're pretty much the only thing in the show that goes with a zing.

So, it's not so much that the public is torturing Katie Price; it's more that it's pointing up the fact that it – the audience – isn't a sucker and not for one minute to be patronised. You might have thought that everyone's – producers', contestants', viewers' – best interest was in the same thing: maximum enjoyment. And yet, given the chance, the public will vote to sabotage. Why? Just because it can.

The mums who've got politicians on the run

David Cameron has been doing a live chat on Mumsnet again. That's apparently where you find "modern mothers" – an important voter demographic. The website has 850,000 users and they were wise enough to have been offended by the way the press focused on "Biscuitgate" when Gordon Brown appeared on the site in October. One unanswered question about his favourite biscuit led to the mums being portrayed as lightweights with no real political sensibilities. In fact, as this week's session proved, the Mumsnet community is as savvy as anything. They worked out Brown had answered his questions faster than Cameron. "I can't believe it takes him at least seven minutes to type the sort of soundbite he spouts on a daily basis," said one user, "Slug". "Bring in the butler and let him do it."

I'm afraid there were a couple of biscuit questions, though – and Cameron made sure to answer. His favourite biscuit is oatcake with butter and cheese – or, anyway, that's what the butler brings.

*It's 33 days until Christmas and the madness has truly begun. My neighbours are putting up their sparkly lights. Ocado wants me to order the turkey. I've got a head full of present ideas for my three-year-old son.

I do like Christmas but I'd like to make a proposal. Could we have it less often? Once every two years would be fun. Now that I'm in my forties the season rolls round too soon. It's inevitable that some of the magic is lost when Christmas comes round every other minute.