TV REVIEW:REMEMBER WHEN Yorkie chocolate bars were huge? That was their big selling point in the 1980s – so big that only a manly trucker could cope with their chunkiness. Now they look if not small then just ordinary – and the Yorkie story gets to the congested heart of Jacques Peretti's take on the obesity crisis.

In this week’s instalment of his insightful three-part documentary, The Men Who Made Us Fat (BBC Two, Thursday), he pointed to the way our food has been supersized by the food industry, with its ever-bigger portions, and by marketing practices such as supermarkets’ multibuy deals on soft drinks and fatty snacks. Why buy one packet of crisps when 16 look like better value?

The supermarket price war in the UK has seen a 138 per cent rise in multibuys in a single year – and there’s no reason to think it’s any different here. The man who started it all, Peretti says, was David Wallerstein, a Chicago cinema manager who in 1972 figured that if he made popcorn portions bigger – big buckets of the stuff, basically – the extra popcorn would cost only a few cents to make but he could charge much more. It worked so well he was recruited by McDonald’s, and so began what Peretti calls “a spiral of upsizing” (and he’s not just talking about the portions).

Much of what we learned about food is already well known, and there were occasional slips into sensationalism – not from the contributors but from Peretti’s gloomy voiceovers: “Decisions made behind closed doors transformed food into an addiction.” But what was particularly interesting was his look at the official response to rising obesity levels.

Despite studies showing that portion sizes and snacking, particularly by children, are the crux of the problem, it’s easier for governments to blame the individual and introduce feel-good exercise campaigns than to tackle the marketing practices of the big food and supermarket companies. “Promoting physical activity is relatively apolitical and passes the responsibility on to the individual,” said Prof Terry Wilkin, who led a pioneering study into childhood weight gain that showed it’s the amount of fat and sugar-laden food children are eating, not their perceived lack of exercise, that’s the problem.

TRUE LOVE(BBC One, Sunday-Wednesday) must have sounded like such a great idea. Five short dramas about love, set in one place – the English seaside town of Margate – with loosely linked characters and a starry cast including David Tennant, Billie Piper, Jane Horrocks and David Morrissey, and screened during the footie extravaganza when other stations are raising the white flag with repeats and slushy movies. It should have been really good. But it was mesmerisingly terrible, not just because the actors improvised – a first for BBC drama – resulting in acting that was hopelessly unbelievable, but also because the characters, like the plots, just didn't add up.

The women were mostly wallflowers ready to stand by their horrible men – except for Billie Piper as a plain-Jane teacher (Piper, plain? Really) who ditched her married lover, realised she was a lesbian and began an affair with her 16-year-old student. They walked off happily into the sunset without social services, an irate parent or even the Daily Mail on their heels. Members of the scriptwriters’ union have nothing to fear.

In Sunday night's drama Tennant, perfecting his lost-puppy look, was a happily married man tracked down by an old girlfriend (Vicky McClure) whom he hadn't seen in 17 years but who was, for no apparent reason, still deeply in love with him. And before you could wonder why didn't she even send him a postcard in all those years, and isn't she a bit of a stalker, they were holding hands on the beach, sneaking off to BBs and on a railway platform swearing their undying love in a Brief Encounter sort of way. But then, just as the credits rolled, he was in bed with his doormat missus, who silently forgave the whole scenario with a little squeeze of his hand.

The actors kept running out of things to say, and their silences were filled with soppy songs by Dionne Warwick, Eva Cassidy, Ella Fitzgerald and even – yes, it got this bad – Phil Collins, as if its director, Dominic Savage, has seen one too many Richard Curtis movies. The BBC buried it late at night in the schedules and squeezed the dramas in over four nights. It was a big enough hint that they knew it was a shambles. Margate looked nice, though.

ON TV3, THE irrepressibly cheerful designer Neville Knott is still flying the frayed and unfashionable flag for interiors shows. Even Phil Spencer's new Secrets Agentsseries, in which he gave advice to people trying to sell their houses, seems to have disappeared from Channel 4 after a short run, possibly because he got tired of saying "declutter" to depressed homeowners stuck in houses they hated and who clearly had no intention of getting the vats of magnolia he recommended to cover up their dodgy taste.

Neville's Doorstep Challenge(TV3, Tuesday) is firmly on the cheap-and-cheerful side. He and his team arrive unannounced at a house whose owner has sent the programme a photograph of a room they'd like made over. In this week's final episode it was Louise, a 26-year-old teacher, with her own new home – see: it still does happen! – in Mullingar whose living room looked, as Knott said, like something "from Shady Pines retirement home".

But, in the time between her sending a photograph of her living room and Knott’s crew arriving at her door, she had replaced the hideous old sofa with a hideous new one (Knott isn’t a man to hide his feelings about soft furnishings) and she insisted it had to stay no matter what. It went. Knott’s talent and ebullience – “It’s high fashion, bang on trend,” he trilled at baby-poo-coloured paint – save this logo-laden show from becoming just another one of those annoying TV3 programmes in which it’s impossible to see anything else but the sponsorship.

Not quite everything is sponsored. Knott’s budget was €1,000, which in the old days of interiors programmes wouldn’t have paid for a verdigris tieback but now has to cover an entire room. So this week the smart-looking sofa was second-hand and the coffee table came from Oxfam – it’s come to that – and it looked great.

Get stuck into . . .

See if the kitchen hard man Gordon Ramsay is quite so tough when he's in Brixton Prison, teaching some real hard men to cook, on Gordon Behind Bars(Channel 4, Tuesday).