Trinny & Susannah: From Boom to Bust, Channel 4/ Nigella Kitchen, BBC Two

They always say that women over a certain age are, in televisual terms, extinct. Well, it seems that science is going to have to get back to the drawing board. Palaeontological reports are coming in from last night of strange terrestrial sightings - sightings of creatures whose skeletal remains were long since thought to be fossilising in the Jurassic substrata known as US cable. And not just one. People caught fleeting glimpses of the Trinnysaurus and the Susannadactyl while others say they saw a Nigellatops chomping greedily in her own pastures. But they can't quite be sure.

Yes, plummy birds have risen again. In their absence things have moved on. The makeover has split off and regenerated itself in myriad massively different (but somehow also totally identical) forms and formats. Telly chefs of every conceivable size and flavour and bogusness have been crammed into the schedules like sardines into tins. You can’t move for the spin-offs and spawnings of the ladies who, once upon a yesteryear, launched themselves as brandnames in the lucrative lifestyle sector.

So what have Trinny and Susannah gone and done? Last spotted defecting to ITV to present a show in which they ludicrously reinvented themselves as marriage guidance counsellors, they’ve tacked across to follow another direction. In Trinny & Susannah: From Boom to Bust, they stripped away the foundation and the lipgloss to reveal their true inner selves. That was the joke anyway.

This was a mockumentary which invited you to accept that the two wardrobe mistresses to the nation have lost the plot: advertising deals have gone south with the TV work; they even find themselves without representation. As one prospective agent put it to them, “You’ve spunked it up the wall.” Nice.

The cameras followed them around (pictured right) as they essayed a series of humiliating tasks in order to resurrect their careers. Thus we found them flogging all-in-one body-shaper knickers (which is an actual product) at a golf and tennis fair, offering makeover advice to jockeys at Ascot, and plucking the unemployed off the street and shoving them back into the job market.

It was all satisfactorily worked through. The grammar of the fake doc – its tropes and tricks - was very much in place. And some of it was genuinely funny. Susannah portrayed herself as a dipsomaniac while Trinny’s bossiness seemed the product of some sort of fixation which, if not quite anal, was certainly gluteal. In one of the most audacious exchanges, Trinny had switched her regular arse massage and colonic irrigation sessions because it was better the other way round. Susannah helpfully unpacked this explanation: “You don’t want to have a pooey arse.” For the record, Trinny flashed her rump at least twice. They also roped in, among many other guest appearances, a very sporting Duke of Wessex.

The question arises of why they did it. It turns out that they are rather good actresses, but then why wouldn’t they be? They’ve been playing souped-up versions of themselves for years (unless they also grab people’s tits away from the cameras). “I don't want to be Susannah today,” said a hatchet-faced Susannah at the golf fair. “I want to be someone else.” It was all frightfully metatextual. It may also be that they wish to say something serious about the perishability of a career presenting on primetime. But finally, perhaps, a willingness to portray themselves as flops was a way of apologising for those risible efforts on ITV in Trinny and Susannah Undress...

They’re only so sorry, mind. Their website advises that Trinny and Susannah are “currently in Australia doing our annual live show tour with Westfield”. That’ll be the Westfield which was respectfully name-dropped at the top of From Boom to Bust. Even when pretending to go AWOL, these ladies are still minding the shopping centre.

And is Nigella ever so indiscreetly mocking her own legend too? The pneumatic mumsiness spilling out of barely fastened garments in Nigella Kitchen is now measuring at toxic levels of insincerity. I’m just back from A&E after having my toes surgically uncurled. “If I’m in a kitchen”, she simpered scrumptiously, “I’m happy.” (Note that indefinite article. They must have ditched the genitive in the title so no nitpickers can ever again accuse her of not filming in her own gaff.)

Anyway, she knocked up a cheesecake in a black satin dressing gown. “I need to disrobe,” she said after crushing a chicken breast bone with her knuckles. Ooh, Missus Saatchi, don’t be a tease. And please stop fellating that king prawn. We know all about your perfectly ridiculous oral fixation. They should have called it Carry On Nigella. I kept on expecting Sid James to leap out of the larder and make a lunge.