Action station: the controller who is not ready to grow old just yet

It was with a certain poignancy that Danny Cohen celebrated his 35th birthday this month, for it was an occasion that signalled his departure from the 16-34 target demographic for BBC Three, the youth channel over which he presides. No longer will he be able to look at shows such as Underage and Pregnant or Teen Angels and think that the digital network is talking 'bout his generation.

Cohen, who is a former head of E4 and brought the hit drama Skins to British television, is such a fast-rising star in the industry that he has been jealously parodied for his age, most notably in a vicious, anonymous and fictitious blog entitled The Secret Diary of a TV Controller, aged 33¾, which lampooned his ambitions, suggesting he wished to explore new television ideas such as "blind comedy" and "my new suicide documentary".

Sat in his glass office cubicle on the sixth floor of Television Centre (where all the BBC controllers are housed), Cohen, dressed in a beige corduroy suit, makes little attempt to be seen as a hipster. He acknowledges that he has "left the demographic" and jokes half-heartedly that "I've got to hang on to my young bones".

He struggles for words when asked what youthful activities he gets up to that might distinguish him from his fellow BBC controllers. Computer gaming, perhaps? "Oh, no. We've got a Wii at home, we love Wii Fit and the tennis and stuff. But no, we live quite a quiet life," he says. Cohen, who took a double first at Oxford and has a deep interest in Charles Dickens, marked his 35th by having dinner with his fiancée, Noreena Hertz, a distinguished author and professor who specialises in economic globalisation.

Such is Cohen's status that he was this year included in Who's Who, citing among his interests not just football, English literature and meditation but, bizarrely, "pickle" and "giraffes". "I just had some family jokes put in," he says. "I do really like giraffes, and pickle... but Who's Who is that thick a book and has got a trillion entries and I really didn't think anyone would notice." He stresses that he has eclectic tastes and, though he found the recent BBC One adaptation of Little Dorrit "really wonderful", says his favourite programme is "probably EastEnders".

BBC Three gets a mixed press. Prominent BBC figures such as John Humphrys and Jeremy Paxman have questioned the need for its existence, particularly when more established parts of the organisation are being cut. Yet the wider industry admires it, naming it Non-terrestrial Channel of the Year at the Edinburgh International Television Festival last summer.

It is frequently rubbished in print by television critics who criticise its output and argue that hit breakout shows such as Little Britain, The Mighty Boosh and Gavin & Stacey could all easily have begun life on BBC Two. Yet Cohen can point to a 16% rise in audience among 16- to 34-year-olds last year, proof that the channel resonates with a group that the corporation often struggles to reach.

Cohen says this is evidence of the success of a campaign he put in place last year to define more clearly BBC Three as a youth channel. "I wanted young people to feel a closer identity with the channel. There was a sense from our research that people watched BBC Three but didn't love it in the way they love some other young brands," he says, adding that he has also tried to "make it feel less like a male channel".

This strategy is naturally reflected in the BBC Three schedule, where programmes such as the documentary Kizzy: Sex, Prams and Exams, about a 14-year-old mum, have made the channel's Born Survivors current-affairs strand a success both on television and online. The hour-long Born Survivors programmes have been shrunk into two-minute "minisodes" for the website, an idea that has been so popular that it is being copied by Panorama.

The World's Strictest Parents is a compelling format in which surly British teenagers spend time living with disciplinarians in such places as Alabama and Ghana. "It's quite a counter-intuitive format, you assume that the strict behaviour is going to be the wrong way but what we find in this series is that the [foreign] cultures were incredibly rewarding for the teenagers," says the controller.

Cohen has commissioned The Belief Season, which tries to deal with faith in a way that engages young viewers. The Teen That Time Forgot features a 13-year-old brought up in a deeply Christian home with little knowledge of popular culture. "Another documentary is about a man who claims to be a psychic surgeon called Gary. He feels a connection to Abraham and that he's channelling forms of biblical energy. We will keep looking to do seasons around themes such as religion or globalisation," says Cohen, who says his closest friends are those he met at his Jewish primary school in north London.

He has high hopes for Being Human, a comedy-drama that features a ghost, a werewolf and a vampire living under the same roof. Initially a pilot, it was commissioned partly because of an online petition. "It's about normal people with an affliction rather than odd supernatural creatures," says Cohen, who, rather cautiously, expresses the wish that the show "does pretty well across the run and that it is something that we can hopefully bring back".

BBC Three, he suggests, is not expected to produce a breakout hit every season. His strategy is to "be targeted but not niche", finding shows that draw young viewers but also appeal to a wider audience, such as Gavin & Stacey and Undercover Princes, which features foreign royalty going incognito in Britain to look for love.

The quest for younger eyeballs does not mean he is abandoning BBC Three's reputation as a comedy channel. Cohen was stung by the comment from Father Ted co-creator Graham Linehan that BBC Three's comedy "polarised and atomised audiences". Cohen says: "Much as I hugely respect him, I think it's unfair of him to pick on BBC Three for being dedicated to its target audience."

He has landed a comedy sketch show from Gavin & Stacey stars Mathew Horne and James Corden, while Ideal, starring Johnny Vegas, maintains the channel's long-standing relationship with Steve Coogan's Baby Cow production company. We Are Klang allows one of the most successful acts at the Edinburgh Festival Fringe to make their television debut in a show based in the offices of a local council. BBC Three has also commissioned The Gemma Factor, which sends up celebrity culture through a young girl's obsession with fame. "It's not set in an urban, cool environment, it's set in a small, rural town," says Cohen. "You don't have to make things cool to make them interesting to young people."

Cohen might be quieter and more bookish than one might expect of the boss of the BBC's young house of fun. And he's getting older, too. But he's not as fusty as some of those who make a living from doing the channel down. "I don't pay too much heed to critics who aren't the type of people we are targeting in the programmes," he says.