Ever since the publication of his incendiary debut Trainspotting in 1993, Irvine Welsh has always been several steps ahead of the cultural curve. Danny Boyle’s massively successful 1996 film adaptation of that controversial novel more or less defined the ‘90s zeitgeist.

But sometimes the Scottish author’s prescience has been a little less obvious. For example, in Lorraine Goes To Livingstone, one of the three novellas that comprised 1996’s Ecstasy, he wrote about a character called Freddie Royle – an odious celebrity who was also a paedophile and necrophiliac. Royle was obviously based on Jimmy Savile; so did Welsh know something then that nobody else did?
“I’d heard rumours that Savile was a necrophiliac and sexual abuser, but I just put this down to the fact that he seemed a bit of weirdo,” the 55-year-old Scotsman explains. “While I didn’t really take this seriously at the time, I thought it would be great to base a character on somebody who really did have those characteristics.”
Welsh is speaking down the line to Hot Press from the Chicago home he shares with his young American wife Elizabeth Quinn (they also have a condo in Florida). Over the last two decades he’s had addresses everywhere from Dublin, Amsterdam and London to San Francisco, Hamburg and Miami. So what’s his favourite city?
“They all have their merits,” he says. “I’m still pretty much tied in to Edinburgh, Chicago and Miami, as I have homes there, but I miss the fuck out of Dublin, London and Amsterdam. I’m over in Dublin again in August for a wedding, and I can’t wait to get back. I was there in April and there was a great energy about it.”
Having previously visited the Sunshine State in 2008’s Crime, his recently published ninth novel is fully set in Miami. While most of his literary output has concentrated on people living dangerously destructive lifestyles (Trainspotting, Filth, Glue, Skagboys), The Sex Lives Of Siamese Twins shifts focus on the American fitness and dieting industries.
When Lucy Brennan, a bisexual personal trainer, disarms a gunman shooting at two homeless men in Miami Beach, the incident is witnessed and filmed by depressed and overweight artist, Lena Sorensen. She passes her mobile phone footage onto the media; within hours, Brennan becomes a paparazzi-dodging celebrity.
Sorenson becomes obsessed with her and signs up as her client. What she doesn’t realise is that Brennan has some seriously Francis Begbie-like psychopathic tendencies. It isn’t long before a Misery-type situation begins. But as Sorenson sheds the pounds, the balance of power slowly shifts.
Fast-paced, acerbically funny and brilliantly written, with lashings of food, sex and whips, clean living has never been described so filthily. Was it a conscious decision to write a novel with two lead female characters?
“No, I just felt that issues I wanted to explore – weight, dieting, exercise and media culture – were more pertinent to women characters, as women under the patriarchy are still subject to greater pressures than men to conform to certain body images. These characters just seemed the most appropriate to address those themes.”
Is he a member of a gym?
“Yes, I go to my local boxing club,” he laughs. “I’ve always been sport obsessed, but held back at it by not being health conscious enough.”
Although once considered the enfant terrible of Scottish literature, Welsh claims to have calmed down considerably on the chemical front in recent years.
“I can’t remember the last drug I took. If we’re discounting alcohol, it probably would be ecstasy or cocaine. But that all seems light years away now.”
As we speak, he’s just returned from an international book tour that has taken him everywhere from Spain to Sydney. A screenwriter and playwright as well as a novelist and occasional travel writer, does he have a typical working day?
“I try not to have typical ones, as it sort of defeats the purpose of working for yourself. But I am an early riser these days, so I tend to go for it in the mornings and bunk off a bit in the afternoon, perhaps watch a movie or read a book for pleasure rather than work.”
He’s also a prolific tweeter, with more than 125,000 followers of @WelshIrvine.
“Twitter can be a distraction, but it’s also quite instructive,” he says. “It’s telling you when you aren’t working efficiently, actually providing evidence of it, unlike just staring out the window.”
The most recent movie adaptation of one of his novels was Filth - about a corrupt, immoral and hedonistic Scottish policeman, brilliantly played by James McAvoy. Was he happy with its reception?
“Delighted!” he enthuses. “Jon Baird and James McAvoy are amazing talents and excellent guys to work with. I was utterly blessed to have them come into my cultural life. Both of them have done amazing things already, and both will go on to do more.”
There’s been much industry buzz about reuniting the original Trainspotting cast and crew for a movie version of its sequel, Porno. Is he concerned about tarnishing the original’s legacy?
“Possibly, possibly not,” he muses. “The tarnishing of the legacy thing is something that concerns us all. We’re going to give it a shot, to try and come up with a screenplay that is strong and vital, and excites the actors and gives a new twist to the characters they play. If we fail, we’ll have failed honourably. But obviously, the objective is to come up with something we believe in, and that will blow everybody away.”
Always prolific and in-demand, he’s currently involved in the production of the Hollywood movie Spring Breakers: The Second Coming. He’s also got another novel finished and ready to go.
“It’s called A Decent Ride, and marks the return of Juice Terry to active service.”
What are his thoughts on the upcoming referendum on Scottish independence?
“I’m pro, and I think it’s pretty much inevitable,” he says. “The British state hasn’t been able to meet the aspirations of any of its citizens, bar the very highest elites in society, for about 35 years now, and has pretty much given up trying. There’s nothing sadder than the weary Groundhog Day mantra of ‘Vote Labour and we’ll sort it all out’. We’ve been doing that and it hasn’t happened, with zero indication that it will.
“Whether there will be a YES or NO vote at the referendum isn’t the most important factor. I think the interesting thing is how people have become active in grassroots politics again. Having scented that power, they won’t give it up readily, and the process towards self-determination will continue. Yes, there are obnoxious wankers on both sides of the debate, but I’m optimistic that most people care about the future of their country and are enjoying having the power to determine it.”

The Sex Lives Of Siamese Twins is published by Jonathan Cape.