Last Night's Television: Defying Gravity, BBC2<br />Who Made Me Fat?, BBC3<br />Jimmy's Food Factory, BBC1

It must have been busy night for British Sugar's press office television recorder last night, with one bit of broadcasting they'll have been very happy with and another that will have them busy working on a rebuttal. The bit they'll be pleased with, surprisingly, came from Jimmy Doherty – hitherto a champion of the unprocessed and free-range – who delivered a singularly toothless report on the chemical processes required to turn sugar beet into sugar as part of Jimmy's Food Factory. The company got a Silver Spoon pack shot out of that one, and then another one (presumably much less welcome) in Who Made Me Fat?, Becca Wilcox's report on why Britain's dieters are playing from the downhill end of a sloping pitch. It's possible, I suppose, that there is a secret agenda in Doherty's series, that by revealing exactly how some of our most familiar foodstuffs are produced viewers might be left a little more suspicious about their claims to nutritional value. But if so, I fear the agenda has been so well hidden that only the already converted will be able to spot it. True, his attempt to home-make a cornflake revealed that they first have to take everything of value out of the kernel, before artificially spraying it back on, but he was distinctly sketchy about just how much sugar and salt is used to make them palatable. And his end of programme summary – "I'm amazed how processing even simple foods requires so much ingenuity.... it's made me look at breakfast in a completely different light" – sounded like the pay-off line from a Kellogg's-sponsored classroom aid, rather than anything that might prod the viewers towards a less synthetic diet.

Who Made Me Fat? came from the Coco Pops school of current affairs. It had bright cartoony graphics and lots of added sweeteners, the most obvious of them being Becca Wilcox herself, a breezily telegenic type, happy to make a fool of herself with the kind of Michael Moore stunts that generally leave poorly paid security guards looking foolish and allow the powerful to get away unscathed. Some of these were flabby and overlong. But there was substance here, too, and moments that embarrassed people who deserved to be embarrassed, such as the Health Secretary, Andy Burnham, whose department had (we were told) steadfastly sidestepped all requests for interviews and who was eventually doorstepped in a rain-swept provincial square. This awkward moment he handled well. Can't do it now, he said. Go back to my office and set up there and I'll give you the interview you want. Only he never turned up, getting a notably pompous civil-service press officer to get all hoity-toity on his behalf. Was his lie intentional or just the latest twist in an already bad day? Impossible to say, to be charitable, but he ended up looking like a dishonest coward anyway.

Wilcox didn't get much joy out of anyone she tried. There was a mealy-mouthed explanation of the grotesque fact that some National Health hospitals should have Burger King outlets, even as we struggle with an epidemic of obesity. A Morrisons spokesman parroted out the company copy line – "Fresh food at affordable prices" – while dodging the hard question about why 63 per cent of its buy-one-get-one-free offers should be for junk food. And the Sugar Bureau simply hid under the desk, unwilling to explain why it produced leaflets for GPs recommending sugar as part of a sensible weight-loss programme. The only person who didn't mince his words into a self-serving slurry was Rod Liddle, taking exception to Wilcox's suggestion that obesity had its roots in capitalist conspiracy. Not exactly a poster-boy for self-restraint, he proposed that people were fat because they were "idle and stupid". It seemed harsh as he said it, but then if you're willing to let big corporations tell you lies and won't do anything about it unless a government does it for you, perhaps no other words apply.

Defying Gravity was a reminder that not all junk food enters by mouth. A multinational drama about a multinational space shot to distant planets it turns out to be about as gravity-defying as a paper-plane with a housebrick payload. "We're in uncharted territory here," one of its characters said at one point, highlighting the fact that we absolutely weren't. This is the kind of space opera that signals global interest by sticking a man in a dashiki into the observation lounge, in which astronaut selection appears to have been made by Abercrombie & Fitch (except for the geeky physicist and the comedy Indian who gets his idioms wrong) and in which the laws of physics are arbitrarily suspended the moment they threaten the budget ("Our grav-suits contain nano fibres that pull us towards the deck electro-magnetically"). The script is terrible too – dentist- poster philosophy that is only likely to get worse as the mysterious entity toying with the mission makes itself more clearly known. In Space Everyone Can Hear You Pontificate. Unfortunately.