Just watched the programme. Thought on the whole it was pretty useful, and hopefully will turn more people onto a low carb, or at least lower-carb lifestyle.
It wasn't without slight irritations though... The whole show, especially the assertion that this was a new thing, smacked of trying to drive book sales at some point a la Michael Moseley. I thought the messages between blood sugar control and gut health were a bit mixed up and could cause confusion (and I really didn't need to see the inside of his pulsing colon for several minutes!). I thought some bits were sound science but were mixed with fairly superficial theories, including the much heralded 'swish sports drink' segment - I've never particularly bought this theory, even when it was held up as a reason for diet drinks making you fat (your body expects the sugary drink and treats it as such despite not getting it)...it all seems a little too convenient and wouldn't explain people who drink diet drinks having no BG spike...not to mention the 'experiment' being flawed - the two bike rides were on different days and there are a million reasons why his performance may differ on those days, including of course the expectation that he may have more energy on one of them making the difference.
Suspect science aside, I thought it was well presented and snappy enough to hold casual viewers attention, no doubt will get a large number of people googling and the bit at the end about the advice being rolled out to GPs can only be a good thing.