Hahaha, well this is all quite funny. This is quite a turn of events.

How this column works - well, I say “works”; compared with chasing the mighty caribou across the badlands of Dakota, it's more “How this column comes languidly into being” - is like this. The TV editor rings up and goes, nine times out of ten: “This is a terrible week for television. The only tapes we've got are for a Channel 4 documentary, called Cancer-Face Fat Dad, about a fat dad, who's got horrific facial cancer. Technically, it's quite novel - it's the first time that Channel 4's Fat Documentaries department has worked with the Disfigurement Documentaries department. Is that a good news angle, maybe?”

My traditional reply - “Can't I just write about Doctor Who instead?” is met with its traditional response: “For the love of God woman, grow up” - and then the TV editor puts what DVDs he has into a Jiffy bag and sends them over to me.

In a nutshell, what I'm saying is, although we try our best to plan ahead and strategise, barren schedules and a shortage of preview DVDs occasionally leave us like media scavengers, working in the post-apocalyptic wasteland of prime-time. So we review whatever we can get our hands on.

This week, however, was quite novel. For it was only when I had inspected this week's envelope, containing BBC Two's impending The Supersizers Go ... , that I suddenly realised what this was. It is the show I was supposed to have presented.

Well, I say “supposed” - that makes it sound quite dramatic. In reality, the production company e-mailed me when I was on holiday. By the time I got back to them, the job had been nabbed by Sue Perkins. As you can see, it was scarcely six fraught months of audition and rejection. I don't, by any means, feel like I did a term at Nancy School.

But, nonetheless, this nugatory brush with the production of the show means that viewing The Supersizers Go ... is not a simple act of television criticism. For me, now, it's like gazing at an alternative reality - a life and career that I could have lived but, unexpectedly, the respected broadcaster Sue Perkins is now living for me, instead.

So here's what I should have spent the last six months doing. Basically, the Times restaurant critic Giles Coren has teamed up with Sue Perkins, aka me. Each week they spend seven days eating in the style of a previous era. In last year's pilot, they ate as Edwardians, and nearly died from a surfeit of pig's head jelly for breakfast. Now given a whole series, Coren and Perkins attempt to kill themselves, respectively, in the style of the Regency, the Victorians and, for the first episode, the Second World War.

Of course, the British diet during the war was one of our few nutritionally exemplary periods. Very little animal fat, huge quantities of vegetables, and the looming threat of a prison sentence if you didn't finish everything on your plate. The-person-who-should-have-been-Caitlin-Moran-but-is-actually-Sue-Perkins - perhaps we could refer to this hybrid as “the Merkin” - chows down on Spam, paraffin cake and grass with remarkable good grace. She also doesn't demur at wearing some manner of knitted Utility torso item - a clothing part which, had I been ordered to wear it, would have made me look like a perambulating Weetabix. She takes that one for Team Merkin very well.

Sadly, after 20 minutes of The Merkin being consistently very amusing, I could only conclude, with great rue, that she is far better at being me than I would ever have been. Not least because, as a fully qualified lesbian, she is safe from the programme's greatest shock: just how hot Giles Coren is in an army uniform. Dearie me. It matters little that, by and large, Giles bolts his food like a hungry goat, and has hair that could do with a good wash. Put him in khaki and a small, side-mounted hat, and some manner of sexual magic overtakes him. Phwoargh. Who knows what would have happened if we had ended up working together? It could have ended in an explosive affair. We could have had a mawkish “his'n'hers” column about our relationship, called “Lovin' Times.”

Our careers would have been doornail dead within a year.

Meanwhile, lovely yet impoverished Sue Perkins would have defaulted on her mortgage, and had to go live in a bin.

Clearly, it really has all worked out for the best.

The Supersizers Go ... Tues,

BBC Two, 9pm

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