Last Night's Television - Celebrity Big Brother, Channel 4; My Big Fat Diet, ITV1

One big snappy family

One thing we know already. It won't be very long before Lucy Pinder, glamour model and self-styled "Tory bird", gets to realise her reported lifetime ambition "to hold a monkey" (there's nothing like aiming for the stars, is there?). There can't be a tabloid picture editor in the land who hasn't already got plans for an eviction Page Three special, in which Lucy's twin claims to fame will be pushed into lubricious prominence by a bemused simian borrowed from the nearest zoo. And since Terry Christian – temporary monarch of Celebrity Big Brother – has already nominated Lucy as the "least talented" of his housemates, this lustrous contribution to British journalism could grace our breakfast tables sooner rather than later. I'm pleased to say that Lucy herself doesn't share Terry's low opinion of her abilities, by the way, laying claim just the other night to a talent that will surely stand her in good stead if she remains in the Celebrity Big Brother house: "I can talk about crap for hours," she announced proudly.

Watching Celebrity Big Brother is a bit like watching a pan of water come to the boil. For ages, you think absolutely nothing is happening, as the politeness of first meeting and the dread of looking bitchy keep all the tensions in check. You find yourself wondering whether anyone's actually remembered to turn the gas on, and seize with a shaming eagerness on even the smallest tremor that shudders across the surface. It always happens, but this year things started off so uneventfully that Channel 4 executives must have been bitterly regretting the decision to allow a bed manufacturer to sponsor the programme breaks. At least six times an episode you were getting a reminder of where you'd much rather be: horizontal and with your eyes closed.

Finally, though, bubbles are beginning to appear on the pan walls and the temperature is getting close to simmering. The rapper Coolio looks likeliest to make things really boil over with a Guantanamo-worthy technique of ceaseless self-regarding babble that has started to peel the veneer of aimiability from the less patient housemates. That and the undiplomatic cackle of glee he released when Michelle (girl-band refugee) told Tina (Brookside alumni and professional gobby Scouser) that she looked like Princess Shrek in her Juliet costume. Ambushed by unwitting Freudian candour, Michelle hadn't actually meant to be unkind (she's not the brightest bulb on the B-list), but the accuracy of the description and the agonising explanation to Tina of why exactly Coolio was screeching like a gibbon (she'd never seen Shrek) provided some of the squirmiest moments in the series so far.

Tina, incidentally, says that she suffers from OCD, a good example of the way in which modern celebrities feel the need to bare the stigmata of their fame. Terry has been grumbling in a wounded way about the envy of the hacks, Ulrika has been confessing to minor panic attacks and La Toya Jackson, utterly bizarrely, seems to have decided that appearing on the show constitutes a kind of therapy for her chronically withdrawn nature. She's only gone into the house, it seems, because she doesn't get out of the house enough. "It's the best thing I've ever done," she announced the other day, peering fearfully over a nose that makes you wonder whether her brother Michael employed a plastic surgeon who was running a Buy-One-Get-One-Free promotion. The only cast member who really has something to complain about, but doesn't, is Verne Troyer, who played Mini-Me in the Austin Powers films and is being treated by several of the female participants as if he's an unusually winsome fridge magnet. Davina shamefully set the tone when commenting on his arrival in the house – "Oh! No! Please!... just too cute!" – but her condescending cooing has been echoed by others since. Truest thing said so far – by a country mile – was a pointed aside by Terry as he watched the group doing one of the tasks. "Big ego, low self-esteem," he said, "That's why we're in the business."

In My Big Fat Diet, Claire Sweeney (graduated with honours, Celebrity Big Brother 2001) decided to give up exercise and nutritional self-restraint in order to see "just how easy it is to get fat". She ate a lot of Magnums and chips (though not together) and generally let things slide and, wonder of wonders, the result was that she went up a couple of dress sizes and began to develop some little baby bra-strap dewlaps. If there are any viewers out there who don't know already how easy it is to get fat, and how heartbreakingly hard it is to go in the opposite direction, they have now been enlightened. I quite like Claire Sweeney, but this was an unsightly spare tyre of a film, about as worthwhile as the stuff that sputters out of the end of a liposuction tube.