This will be unusual.

Is ‘fat’ really the worst thing a human being can be? Is ‘fat’ worse than ‘vindictive’, ‘jealous’, ‘shallow’, ‘vain’, ‘boring’ or ‘cruel’? Not to me; but then, you might retort, what do I know about the pressure to be skinny? I’m not in the business of being judged on my looks, what with being a writer and earning my living by using my brain…

I went to the British Book Awards that evening. After the award ceremony I bumped into a woman I hadn’t seen for nearly three years. The first thing she said to me? ‘You’ve lost a lot of weight since the last time I saw you!’

‘Well,’ I said, slightly nonplussed, ‘the last time you saw me I’d just had a baby.’

What I felt like saying was, ‘I’ve produced my third child and my sixth novel since I last saw you. Aren’t either of those things more important, more interesting, than my size?’ But no – my waist looked smaller! Forget the kid and the book: finally, something to celebrate!

So the issue of size and women was (ha, ha) weighing on my mind as I flew home to Edinburgh the next day. Once up in the air, I opened a newspaper and my eyes fell, immediately, on an article about the pop star Pink.

Her latest single, ‘Stupid Girls’, is the antidote-anthem for everything I had been thinking about women and thinness. ‘Stupid Girls’ satirises the talking toothpicks held up to girls as role models: those celebrities whose greatest achievement is un-chipped nail polish, whose only aspiration seems to be getting photographed in a different outfit nine times a day, whose only function in the world appears to be supporting the trade in overpriced handbags and rat-sized dogs.

Maybe all this seems funny, or trivial, but it’s really not. It’s about what girls want to be, what they’re told they should be, and how they feel about who they are. I’ve got two daughters who will have to make their way in this skinny-obsessed world, and it worries me, because I don’t want them to be empty-headed, self-obsessed, emaciated clones; I’d rather they were independent, interesting, idealistic, kind, opinionated, original, funny – a thousand things, before ‘thin’. And frankly, I’d rather they didn’t give a gust of stinking chihuahua flatulence whether the woman standing next to them has fleshier knees than they do. Let my girls be Hermiones, rather than Pansy Parkinsons. Let them never be Stupid Girls. Rant over.