The South Bank Show, ITV1<br/>The Duchess in Hull, ITV1<br/>The Supersizers go ... Wartime, BBC2<br/>Reverend Death, Channel 4

Television, Gore Vidal wearily announced on The South Bank Show last week, is a medium used for perpetrating lies "all over society". We were supposed to take that on trust. I'm glad he remembered to lay into TV, though, because every other institution worth noting was subjected to his magnificently urbane disdain: from the president ("demented"), to John Updike ("I'm sure he has virtues, it's my fault that I don't see them.") to the American republic itself ("The game's over. The empire's shot."). Beside him, Cassandra looks like a tapdancing ray of sunshine.

Anyway, lies, damn lies and transmissions. My feeling is that fewer half-truths get past us on TV than on other media. If you can see someone's face and hear their voice, your instincts have more to go on. Klaxons of suspicion go off in your head, and mine honked once or twice on The Duchess in Hull. This benighted programme saw Fergie handing out lifestyle advice to the Sargersons, an overweight, underprivileged family living in Hull. She has recently established herself in America as a spokesperson for Weightwatchers, but still, the idea that she should be best placed to tell anyone how to conduct their personal arrangements is so clearly grounded in class snobbery, a de-haut-en-bas idea of philanthropy, that even the Victorians would have blanched.

But there she was, bounding into their home. Before she arrived, the family discussed who they thought they might get. "Nigella Lawson or Vanessa Feltz? Maybe Kerry Katonawa [sic] or that bloke off Trisha bootcamp..." When Fergie arrived, there was a resounding silence. "Oh my God, that's so sad," she blathered. "I just knew they wouldn't know who it was." Klaxon alert!

Was this venture motivated by pure goodness, or something more businesslike? At the end of the programme she was filmed urgently snaffling a sandwich. "It's a Weightwatchers sandwich, apparently," she said, slightly sheepishly. The great British viewing public is not daft. We know a good bit of product placement when we see it.

Ditto a career comeback attempt. "I reckon it's just a publicity stunt," said one of the Sargerson boys. His mother was less cynical. "It's a fairytale," she said tearfully. "Someone listening to my problems and trying to help." Central casting has always filed Fergie as the Ugly Sister or, at best, Buttons. Now she was the fairy godmother. This was all turning out quite nicely for the Duchess. A pity viewers had to sit through interminable "positive" musak and close-ups of sausages. Still, there was room for a few enjoyable gaffes. When one of the sons was off school "sick", Fergie was outraged. "He's as sick as my big toe!" Given her past, another metaphor might have been appropriate. Or is her foot always going to be, ahem, in her mouth?

The Supersizers Go ... Wartime was an account of what we ate for Victory: the potato pie, the snail and nettle consommé, the snoek. Presented by Giles Coren and Sue Perkins, it was a mixture of history and clowning, with the clowning taking precedence. You could tell this by the way Perkins said "subscription" instead of conscription and "Bletchingly" instead of Bletchley. The comedy, on the other hand, was perfect every time – right down to the dog who chased Perkins when she went out wearing gravy stockings (Coren, inevitably, licked them off afterwards).

Even if the levity does grow relentless, they are a fun pair and there was plenty of nice detail, such as a recipe for mock crab (margerine, dried eggs, vinegar, cheese and salad cream, since you ask). But all the larking about means this is mock history. I wish I wasn't looking forward to the next instalment (The Supersizers Go ... Restoration), but I am.

Jon Ronson's Reverend Death was a vividly creepy portrait of the irresponsible face of euthanasia, Dr George Exoo, a Unitarian minister from West Virginia who claims to have assisted 102 suicides. Ronson started off with a sympathetic attitude, but slowly grew disenchanted. Very slowly. "Now I've spent a few years with George I'm beginning to wonder if he's too in love with death ...", he mused. There is a problem with these faux-naive broadcasters, who are always beginning to wonder if it gets dark at the end of the day. Just because it's called the Idiot Box doesn't mean you have to pretend to be one to get on it.

But Ronson redeemed himself, boldly confronting one of the self-described midwives of death: "It sounds pretty sick to me, and I don't think you should do it."

Unlike, say, Mark Dolan, he is a presenter of depth, whose simple style gained momentum. He ended Reverend Death with powerful misgivings about Exoo's vocation. "I wonder how much less corrupting the love of a calling is than the love of money."

Great stuff, apart from one annoying little word. I wonder, can "wondering" be banned on TV?