SOUTH Beach, Miami. No-nonsense fitness instructor Lucy Brennan (‘Hardass Training — No Excuses’) sees a man with a gun and she takes him down. One perfect kick, a few perfect punches, he’s on the ground and she’s a hero. The entire incident is witnessed and caught on video by bystander Lena Sorenson, a large, unhappy woman. Lucy is suddenly Miami’s newest star and Lena is entirely enamoured.

Irvine Welsh’s The Sex Lives of Siamese Twins is his first novel to be entirely set in America and to feature a full cast of Americans. It’s also his first novel with two female leads — Lucy and Lena, a trainer and her depressed, overweight client. They begin their relationship as trainer and client, but very soon grow closer, forming a warped dependency on each other. Eventually, each woman finally acknowledges her own personal albatross.

The eponymous Siamese twins of the novel are 15-year-old Annabel and Amy from Arkansas, who want to be surgically separated so that one can try to lead a romantic life. Documented via constant news updates and bulletins, America is enthralled by the twins’ struggle for independence, watching as a young boy asks one of them out, as the other twin is dragged along to her sister’s romantic engagements, both girls resenting the constant presence of the other. Their attempts at living separate lives (in as much as they can, being physically attached) are played out on television screens in gymnasiums and cafes where Lucy and Lena work out and eat, the twins’ story laid out as a sort of framework for that of the older two women — both pairs of women being trapped by a strong co-dependency. There’s nothing very subtle about this mirroring of course, but Welsh has never been known for subtlety and it is interesting nonetheless.

Welsh is very good at creating unsympathetic characters who are still extremely engaging. Whether it be the heroin addicts in Trainspotting, the dodgy police officer in Filth, or the amateur pornographers in Porno, his characters are often abusive, immoral and fairly disgusting. Of course, they’re all also ultimately human; broken and flawed — but so very human. With Lucy in The Sex Lives of Siamese Twins, Welsh has created one of the worst, most aggressive and irritating characters he has ever written — and also, inevitably, one of the most interesting. He’s also created an extremely American voice for Lucy — it’s so American it’s almost a caricature. Or perhaps that is the point. Sometimes the references to things like American sports in Lucy’s narrative feel a little strained and the vocabulary of fitness training is clearly heavily researched but then “numbers are the great American obsession.”

The constant fight for health, strength and longevity is Lucy’s obsession and many of her thoughts are informed by a health management manual that focuses on efficiency. She is always unapologetically aggressive, with violent reactions to things she dislikes and plenty of sexist comments involved in her perpetual fat-shaming of everyone who is not as fit as her. Even the women and men she finds attractive are referred to with sexist slurs, their bodies objectified and used as “just a piece of gym equipment.” It’s funny and disturbing, especially when you wonder why you’re finding a woman’s deeply-rooted misogyny amusing. But then, making you laugh while making you feel just very slightly sick is also a classic Welsh trick.

In certain ways, Lucy is the polar opposite of, say, the addicts and hooligans of Trainspotting (probably still Welsh’s best known work). She won’t touch drugs, doesn’t smoke, barely drinks, counting out calories and alcohol units precisely to make sure nothing exceeds her daily dietary allowance. She isn’t ‘down with guns,’ she isn’t into uppers or downers, instead relying on exercise — her every waking thought is about nutrition, health, strength and empowerment. It’s funny and extremely contemporary and yes, at times overbearing, considering Lucy’s utter lack of sympathy towards anyone who is not in the prime of life. She considers her clients to be just large piles of flesh she wants to carve into something better, not people with personalities or issues. For instance, a client is a “cellulite-caked fatty,” inciting the opinion that an early death is inevitable for all unhealthy people: “bullets or burgers, I don’t care how they bite.”

But there are cracks in Lucy’s armour that Welsh lets us see right from the very start. She’s past 30 and worried about how long her career will last. She protests far too much about strength — both physical and mental. “Praise is weakness,” she tells us, “it’s the staple diet of the quitter. The strong woman doesn’t need that […]. The strong woman just knows”. Her understanding of herself as an empowered woman is strange, strained and very clearly hiding something deeper and more troubling. It is almost as if she has created herself in another image in order to protect herself. Everyone else around her is “a fake,” weak and worthless of her time. Even Lena is nothing more than a “time-wasting trash disposal.” It is Lucy’s unravelling we are horrifically fascinated to watch, just as much as we are fascinated with the extreme methods behind Lena’s weight loss and evolution. Lena, of course, is the perfect foil to Lucy’s aggressive self-aggrandising behaviour.

Lena, at first, seems to be a silly, insecure woman, desperate for positive reinforcement and hating her physical self, her work, her past. “You’re mutilating yourself Lena,” Lucy tells her, “cause that’s what it is Lena — self mutilation with sugar and fat!” It doesn’t take long for Lucy to see past Lena’s insecurities and find the person she could be, to see how “repulsive and how […] beautiful” she is; and it’s not long before Lucy starts to obsess about carving the “real” Lena out of the “fat suit.” There’s a strong focus on physical transformation but ultimately, something has to change in each woman’s mind in order for her to accept herself.

It’s an odd, warped compulsion that ties these two women together, a simultaneous repulsion and attraction, just as in most of Welsh’s stories. His work tends to you leave you with concerns about sexism, worries about all sorts of addictions and the worst, most misogynistic curses ringing in your ears. You feel dirty and unwashed, and criminal, as if you too have abetted a transgression. The Sex Lives of Siamese Twins does most of that, in its own unique way, just as his other successful books have done. And if you’ve chosen to read Irvine Welsh, that’s exactly what you’ve signed up for.

The Sex Lives of Siamese Twins

(Novel)

By Irvine Welsh

Jonathan Cape, UK

ISBN 0224087886

480pp.