A moment of reflection... Pete Bennett. Photograph: Sarah Lee

I've worked out that Posh's waist measurement* is greater than the average age of the celebrities - Billie Piper (24), Wayne Rooney (21), Big Brother winner Pete Bennett (24), Jade Goody (25) and Chantelle "Oh my God! My 15 minutes is over" Houghton (23) - who've had their autobiographies published this year. Surely you need to have had a life before you publish an entire book - as opposed to a 100-word column in OK! - about it?

The traditional idea of an autobiography is of an older person looking back on their - hopefully eventful - life from near its end. Mark Twain wrote his autobiography in his seventies and Bertrand Russell in his eighties.

Also, it's a life story, see? And if you are slap bang in the middle of the main action - attending photo shoots, doing rounds of TV interviews, negotiating another £10k for Celebrity Love Island and avoiding eye contact with Dean Gaffney when entering VIP areas - then the benefit of hindsight is lacking.

Plus, there is simply not enough material. Take the autobiography of Benjamin Franklin; it's along the lines of: "Born into an impoverished Bostonian family of 15, I had little schooling but as a teenager helped my brother set up the first American newspaper. I then became a scientist and invented the lightning rod and bifocal glasses. I wrote lots of books and founded the first hospital in America. After the American Revolution I wrote the Declaration of Independence with my four other founding fathers before becoming ambassador to France, campaigning for the liberation of the slaves and inventing some more stuff."

He just had that bit more to write about than, say, Jodie Marsh (27), whose life story - as described in Keeping It Real - is: "I was born into a middle class family in Essex, got bullied at school, appeared on ITV's Essex Wives, got my kit off repeatedly and went out with that bloke from Blazin' Squad."

For once, Kerry "60-piece frozen prawn platter for a fiver" Katona has got it right (although not in terms of her recommendations for Christmas finger food). Too Much Too Young, the title of her "life" story, says it all. At 26, she definitely is too young. Publishing houses should stop thinking only of short-term sales and ban anyone under retirement age from bringing out an autobiography.

*In inches, obviously. And here's the maths: 24 + 21 + 24 +25 + 23 = 117, 117/5 = 23.4 Erm, OK, maybe Posh's waist measurement if she had participated in last week's World Pie Eating Championships in Wigan.