A study by the Broadcasting Standards Council shows that 14.1 per cent of teenagers between 15 and 17 regularly watch youth programmes. More than a quarter of the same age group never watches them at all.
It was not always thus. Channel 4 in effect created youth programming a decade ago with The Tube, a show that had widespread appeal. It was scrapped when Mike Bolland, its creator - now managing director of the independent producer Channel X - moved on. However, its anarchic production values survived under his successor, John Cummings, who commissioned Network 7, created by Janet Street-Porter and Jane Hewland. Hard-hitting and flippant - 'mixing knickers and cycle shorts with famine and revolution', as Hewland puts it - Network 7 set the standard for factual youth programmes in the Eighties.
When that show in turn fell victim to another regime under Hilary's predecessor, Stephen Garrett, Street-Porter and most of the production team moved to the BBC, where their early evening Def II slot gave the corporation the edge over Channel 4's disastrous replacement, Club X. But critics now argue that the BBC's output has become stale. And other youth programmes, they say, are also showing their age.
'People in youth television have got out of touch,' says Jane Hewland, who now produces the video games show, Gamesmaster, through her own independent for Channel 4. 'They go on lumping 16- to 24-year-olds together in one grouping, but that grouping does not exist any more. Those who have not got jobs, bought property or settled down with somebody may have something in common, but those that have, have more in common with me.'
She keeps in touch with young people's tastes through her 12- year-old son, who vetoes most of her programme proposals - 'he's virtually my business partner' - and believes it is his age group, the 12- to 18-year-olds, that youth programmers should be targeting. 'These are the only kids approximating to a homogenous group these days.'
Hilary agrees it is important for television to appeal to a younger audience, not least because its constituents decide which channel is watched in the average household. But he is adamant that youth programming should not be abandoned. 'It's a sector of television that is vitally important. Part of its function is to keep television alive. As the industry moves towards short-term contracts, and training schemes are cut back, youth programming is one of the only routes into television for young people.'
For Channel 4, Hilary thinks, a commitment to youth programming is particularly important as the company heads towards commercial independence. 'It's a question of branding. Channel 4 needs to be youthful and questioning, that has always been its persona. It must stay with that.'
Hilary also believes there is still a viewing market, defined less by age than by 'attitude', that wants 'television that is fresh and not afraid to ask questions, programmes that are slightly wild and different and unafraid to stand against the status quo.'
For Hilary, the programme that epitomises these qualities is Channel 4's The Word, which beats even The Tube when it comes to chaotic production values. He has silenced speculation about its future by recommissioning it for an extended third series of 21 episodes, starting in October.
Insiders feared Hilary might axe the show - which notched up a relatively healthy 2.6 million viewers during its last series - in a fit of 'new-broom' activity. He admits he initially felt pressurised to do so, 'but I figured it would be perverse to get rid of something good just for the sake of being seen to be making radical changes. If it ain't broke, why mend it?'
He has also commissioned a spin-off (working title Backstage Pass), which will take viewers behind the scenes and 'poke fun at the programme itself'.
Hilary, 33, is a father of two who lives in south-west London. His lifestyle does not match that of his opposite number at the BBC, Janet Street-Porter, who at 45 reputedly still goes clubbing at fashionable youth haunts such as Notting Hill Gate's Subterrania. But he maintains this does not matter.
He has spent most of his career in youth programmes - including a long spell in the BBC youth programmes unit in his native Northern Ireland, which he eventually headed, and a stint as Street-Porter's deputy in London. He now thinks his job is 'not to be an ageing teenager but to listen to young people, get information from them and involve them in making programmes'. His message to independent producers intending to submit proposals is: 'I don't mind if the person overseeing the project is 30-odd, but there must be younger people in there coming up with ideas and influencing the style. That is why The Word worked so well, there were a lot of young people on the team.'
Programme ideas he is considering include a drama series by and about young people, and a documentary series with the same ethos, with content ranging from how to start a rock band, to how a police raid works and why people take drugs such as Ecstasy - 'But I don't mean a 27-year-old Oxbridge graduate telling you about why people take it. I want to hear from young people about their own experiences.'
Youth programmers at the BBC are aware that the competition is hotting up. Although figures for programmes such as Reportage, the Rough Guides and the sports show, Standing Room Only, were averaging two million, other shows in the Def II slot, such as Normski's Dance Energy and Artrageous], were notching up less than one million. Tony Moss, the BBC's deputy head of youth programming, says: 'We are planning to revamp and expand Def II in the autumn, with more of an emphasis on teenage comedy, science fiction and sport.'
Dance Energy will become more of a comedy and entertainment show and, with Rapido not being given a new series, music-based programmes for young people on the BBC will be virtually phased out. Even poor old Top of the Pops - which comes under the light entertainment department - faces an uncertain future. 'As the music scene is so fragmented now, it is increasingly difficult to please large numbers of people with one type of music show,' admits Moss.
The declining proportion of young people watching any kind of television is a problem. 'But attracting more viewers cannot be our sole criterion. We want our programmes to inform, challenge and educate,' Moss says.
Hilary agrees, but adds: 'We mustn't be too serious and issue based. Of course young people are concerned about issues that affect them, but they are quite capable of reading about them in a newspaper. What they also want is good anarchic fun.'