Graham Norton admits he's a little worried about how his first novel, Holding, a dark tale about an Irish village whose community is thrown into disarray when a body is found, will be received.

It's not racy, it's not very funny and, well, he's known for being a humorous chat show host rather than a literary figure, although he has written two previous memoirs, So Me and The Life And Loves Of A He Devil.

He'll be going on a book tour to promote Holding, but laughs at the notion of now being on the literary circuit.

"With a memoir, you're fine because I'm just a turn," he says candidly. "This will be a very different experience. The worst that can happen is that nobody buys a copy of this book and the people who got it for free (reviewers) hate it. And then I won't write another one. But I've still got a job, I'm still fine."

Holding is set in the remote Cork village of Duneen where the lives and secrets of three spinster sisters and their loved ones are unravelled as an investigation into the death progresses. It's a gentle read as the story meanders amid the characters and the setting. There's hardly any swearing and very little sex.

"There's a little bit of sex in it, but not a lot. There's porn for that," Norton jokes.

His fictional hero is an overweight, under-valued sergeant, PJ, who lives a lonely, uneventful life punctuated by the next meal, until a body is discovered.

Why did Norton make his hero an unattractive, fat character?

"In my head, that's who I should be. Not a detective, but fat.

"Everyone's got an eating disorder, a weird relationship with food. When you talk to people about food, you think, 'Wow! You're just as crazy as I am'. In my head, I'm fat, and in reality, I would be if I didn't go to the gym and ate what I wanted to.

"I don't know if I'd be Channel 5 documentary size, but I would be large.

"If you were living back in the day, you worked hard to get the food and all the food you got, you ate, because you needed that energy," he continues.

"Today, we are on running machines, running nowhere to burn off calories we clearly didn't need. Everyone in modern society has a pretty odd relationship with food."

He keeps himself trim with regular visits to the gym, even when he's on holiday in Ireland, and remains busy with a new series of his chat show, which begins on September 30, and he'll be hosting Gary Barlow's search-for-a-star show Let It Shine in the New Year.

He also manages to fit in his Radio 2 Saturday morning slot and his agony uncle column for the Daily Telegraph.

There are pros and cons to being a famous name before your first novel is published, he observes.

"The good thing about being 'Graham Norton off the telly' is that I get my novel published. The bad thing is, it's like I'm looking over the shoulder of the person reading it, that I'm somehow coming between you and the book, so I wanted to make that less likely by not setting it in London and not having me in it."

He could have written the novel under a pen-name, but then it probably wouldn't have been published, he chuckles.

Surprisingly, though, he enjoyed the writing process away from the hubbub of television.

"Everything else I do, by its very nature, is collaborative. On the chat show, my job is to collaborate and make the characters entertain the nation. Writing a book is the absolute opposite. It's just me wrangling some words into an order to convey moods and emotions and a sense of place."

Once again, he'll be putting himself out on the literary circuit, having already written two memoirs.

"Literary circuit?" he guffaws. "The minute you start talking about it, you sound like such a pretentious goon."

He may seek to distance his own similarity to his fictional characters, but his hero detective is also a bit of a loner, which isn't so far from Norton when he was a young man.

He grew up in Bandon, West Cork, a Protestant in a Catholic area, and his first autobiography So Me painted a picture of a young man who was gay, but confused, his sexual awakenings revealed along with his adventures as an actor and comedian, before entering the realms of TV.

He had a peripatetic childhood, moving from place to place, thanks to his father's job as a Guinness sales rep.

In Holding, his fictional depiction of small-town life in Ireland is very realistic.

"Growing up, we'd move around a lot, so wherever we'd go, you'd hear the local stories. It's such a cliche, but Irish people love to tell stories and we can't shut up. If you're in a pub in Ireland, by the time you go home, you'll have some new stories."

Norton, who has homes in London and Ireland, is among the highest paid BBC presenters and is well aware of the criticisms made in recent years about the exorbitant fees commanded by top BBC stars.

But he has said: "If you look at what proportion of the licence fee goes on paying on-screen talent, it's something tiny, not even 10%. That's for everybody who appears. For me, the big question is trying to figure out what that remaining 90% is spent on. That would be interesting...

"Most of the big earners pay their way. My show is shown in a bunch of countries and pays for itself."

While he tries to sort out other people's problems in his agony uncle column, he remains single and has said that he may never settle down.

"I clearly am difficult to live with," he has said. "But the good news is, I don't find me difficult to live with, so I'm very content."

He lives with his two dogs, a Labradoodle called Bailey and Madge, a terrier.

At 53, he has no plans to reduce his workload, although he could clearly afford to.

"I can imagine cutting back and doing fewer shows, but I still really enjoy it. What would I do instead? What would I enjoy doing more than that?

"I do like doing nothing, but when nothing isn't a treat, the thrill of nothing would wear off quite quickly. I think it's good to keep your spare time precious, then you can really enjoy it."

:: Holding by Graham Norton is published by Hodder & Stoughton on October 6, priced £20. For book tour details, visit www.readholdingtour.com