Last Night's TV - Jamie's Food Revolution Hits Hollywood, Channel 4; Home Is Where the Heart is, ITV1

When there's no appetite for change

I don't know whether Dino Perris was disappointed or relieved to find Jamie Oliver turning up at his Los Angeles fast-food restaurant, but it clearly wasn't who he was expecting. "I thought it was the guy who's always berating people," he said to the camera in Jamie's Food Revolution Hits Hollywood. He'd been bracing himself for Gordon Ramsay, I think, but he'd ended up with the less sweary one, the one who prefers coaxing and exhortation to character assassination. Quite a lot of berating in the mix here too, as it happens, but it's a kinder, cuddlier sort of scolding. After mixed results in the rural town of Huntington, Oliver has moved his campaign for healthier eating to Los Angeles, where 650,000 school meals are served daily. And initially at least it doesn't look as if metropolitan West Coast sophistication is going to be any more welcoming to him than backwoods of West Virginia. The Los Angeles school board had flatly refused to let him into any of their schools, and Jamie was reduced to going on to a local radio station to beg for parental help.

Things weren't going much better with Dino, whose drive-in restaurant had been selected for a nutritional makeover, intended to improve the quality of the ingredients and reduce the quantities of fat and sugar. Dino wasn't interested in changing his menu at all. He was quite angry at the suggestion, he said. "Not angry to the point that I want to harm him," he added, but still, you get the picture. Jamie emerged from this utterly disheartening encounter unbowed. "This could be great... this could be great!" he said outside, which is why he's so lovable really, because of the persistence of hope in the teeth of discouragement. Discouragement had some really big teeth too. When Jamie took advantage of an open forum at the Los Angeles school board meeting to have another crack at their members he got a bureaucratic brush off, and the only person prepared to speak to him on camera was a local crazy who'd come to warn the board about the cracking of the Seventh Seal. A stunt designed to show Los Angeles parents how much sugar was being added to the milk their children drank didn't go too well either. "I'm going to do my own presentation on flavoured milk and it's going to be epic!" said Jamie, on his way to the venue. He was hoping for a supporting cast of thousands but in the end just a handful of people turned up to watch him fill a school bus with 57 tons of sugar, and you got the feeling that not a lot of them were fans of white sugar to begin with.

Jamie did look distinctly crestfallen at this, and you wondered whether his passion will be quite enough to counter the entangled barriers of political expediency, apathy, corporate interest and patriotic bloody-mindedness that he's up against here. If there is a criticism of his approach – and even mentioning it feels like climbing on top of the rock while Sisyphus is attempting to heave it uphill – it would be that his incredulity at people's choices can occasionally come across as a naivety about the complexity of the systems involved. But then you remember the sea of plastic-wrapped microwaveable trash that parents had brought in as an example of their children's school lunches and figure that even a handful of converts is better than none at all.

Home Is Where the Heart Is – another piece of television activism – also works one person at a time. That's what television likes, after all, human faces, and if some of those faces are instantly recognisable it's even better. So, instead of a documentary about the current provision of services for young people in which politicians might be put on the spot, ITV gives us a kind of immersion challenge in which various celebrities take the dispossessed into their own homes and act as mentors for them. If these people were easy to mentor, of course, they wouldn't be on the streets in the first place, so the first episode was largely taken up with celebrity exasperation. This week – with just seven days left in which to put right the damage done by decades – the mood had to get a little more positive. Jim, a chronic alcoholic who has been living with Colin and Justin (you remember them, interior decor), was invited to give up the beer. Alex James, meanwhile, whose exasperation was greatest last week, had worked out a way to motivate Danny, whose lack of appetite for manual labour had now become unignorable. First of all, he persuaded him to attend a support group for people who hear voices. "I used to get John Lennon," said one of the fellow members, "and thankfully since I've been coming here he's gone... which is quite nice because he used to finish all my sentences when I was thinking." Realising he wasn't alone perked up Danny no end, as did working on Alex's pizza stall at a farmers' market. By the end of the programme, he looked as if he might have a place to live and a job, working in a restaurant kitchen, as did Bridgette, who'd been staying with Anneka Rice. Jim, meanwhile, was still registering 0.00 on the breathalyser, and insisting – contrary to all advice – that he could make a go of things if he got a flat of his own. So three down – possibly, with a following wind. Only a few thousand to go.