How Luke Evans swapped Welsh valleys for Hollywood Hills

The opening shot of

When we meet for lunch near his Shoreditch flat, Evans has a strong handshake, searching, luminous eyes, and a wonderful Welsh voice, as sprung and resonant as Richard Burton's. He orders a Diet Coke and grilled fish, as part of his healthy routine – although Gwyneth Paltrow told him off for drinking Diet Coke when he sat next to her at a Louis Vuitton party. 'She said: "No honey, it should be water all the way,"' he recounts with a twinkle. Evans looks every inch the film star in the making – apart from a distressingly weedy goatee. But even this is part of the package. 'Luke is growing his facial hair for his next film, The Three Musketeers,' his publicist emailed me from Los Angeles the night before our photoshoot, adding sternly 'and he isn't allowed to cut it'. Luke is playing Aramis alongside Matthew Macfadyen as Athos, and the day after our interview he was due to fly to Germany for swordplay, ropework and doublet-and-hose action. 'Wearing a doublet will be like wearing a duvet, after all the armour I've had to carry lately.'

His last role was a breastplate-baring Zeus in Immortals, a big studio epic also starring John Hurt, Freida Pinto and Mickey Rourke. If it makes Evans a star when it comes out next year, it won't have happened easily. The film's premise is that each of its gods are permanently at the peak of their physical prime, so Luke was sent to Montreal for seven weeks of dedicated physical training.

'I literally felt like a zoo animal. Sleeping time, feeding time, training time. I had two trainers, one for Tabata, which is a cardiovascular system that keeps your heart-rate up and burns calories, and one for weights. I'd wake up, eat, train, have a shake, train, eat, sleep, train, have a shake, train and go home to bed. I worked very hard and I loved it. It changed everything. I'm two stone lighter now and have taken two inches off my waist. I always wanted to get into proper shape. Attaining it is the hard thing, maintaining it seems to be OK, because I know so much more about what to eat and drink.'

His cocktail of choice is vodka, lime and soda, which the Tamara Drewe producer (and mother of Lily Allen) Alison Owen overheard him ordering. 'She told me it was known as a "Skinny Bitch",' he laughs. 'I haven't had a kebab for a year and half now,' he adds with a touch of sadness. 'That's what I miss You can take the boy out of the valleys, but you can't take the valleys out of the boy.'

He grew up in the small village of Aberbargoed, the only child of a builder and a housewife. They were a young couple – 19 and 23 when he was born – and both are devout Jehovah's Witnesses. 'That's what I did for the first 16 years of my life.' Spread the Word, door to door? 'That's it.' What impact did that have on him as a child? 'You're knocking on people's doors every week, in other villages down the valley, so you do develop a sense of confidence, to deal with the knock-backs and with people not wanting to speak to you.' It was a happy home – 'they're people with good morals and standards. No swearwords were allowed at home at all, ever,' – and Luke only gradually moved away from the faith as a teenager, leaving behind Creationism and the total ban on swearing. By 16 he had his own ideas. 'I wanted to live my life. I didn't want to upset anybody but I had a clear vision of how I wanted to live and it had nothing to do with religion.'

He still speaks to his parents every day. 'I'm very close to them, it's the way I've always been, ever since I left home. You've got a lot on your shoulders being an only child. You've got to make them proud.' He can't wait for his grandfather, 'a strong man with white mutton-chop whiskers and an amazing allotment', to see him playing a son of the soil in Tamara Drewe. But his parents have never attended his premieres. 'No, I don't think they ever will. Too glitzy.'

School, Bedwellty Comprehensive, was more difficult. 'I was bullied at school, I was very unhappy. Being a Jehovah's Witness, being an only child in a small village you only have to be a little bit different and you're vilified.' The bullying wasn't physical, he says, just a continual alienation from his peers. On his first day out of school aged 16, he went to River Island and got a job shelving shoes. He saved £15 per week for acting and singing lessons, and a year later, won a scholarship to the London Studio Centre, a college specialising in musical theatre. 'Oh, it was wonderful being able to sing and act every day. I'd always thought it would just be a creative vent and I never thought I could do it for a living. So the way things are now is just amazing.'

After three years' training he won roles in musicals La Cava, Avenue Q, Miss Saigon and Rent. He created the leading role in Boy George's Taboo, and for a while he was close to Boy George. 'We kept in touch until he moved to New York. He's a very talented man and I have the utmost respect for his talent, but I think he's very detached from what we would think of as a normal life. I invited him to the first night of Piaf at the Donmar, but he didn't stay on to say hello afterwards and I haven't seen him since.' Piaf was the last musical Luke appeared in, as, after a stint on Crossroads, he gained a good film agent and his career took off.

'Now I'm 31 I feel really comfortable in my skin for the first time. I feel like a man. Everything seems to have come together. I look in the mirror and I don't mind what I see.' His brief appearance as Apollo in Clash of the Titans last year took him to the Golden Globes. 'It's a lot of fun being dressed by designers and surrounded by publicists. If the boys at school could see me now' Working on Tamara Drewe the cast and crew had 'wonderful fun', as Stephen Frears attests. 'Luke even persuaded me to sing the 'Green Green Grass of Home' with him at karaoke one night, so he must have compelling powers.' Gemma Arterton's then boyfriend, now husband, Stefano Catelli visited the set. 'They are a lovely couple to be around: two people who love each other and just have that energy. He's in fashion, a very snazzy dresser. And she's a diamond. She'll be a friend for life. Their wedding was in a castle in Andalucia, but I was beefing it up in Montreal. I regret not being there but being an actress she understands. You can't say "no" when a huge engine of machinery and people are waiting for you. I've sacrificed an awful lot, in terms of friends and family, but it's worth it.'

Luke lives alone in Shoreditch with his beloved tropical fish. 'They're very hard to keep and temperamental but they've stopped dying on me.' He has a temperature-controlled tank of brightly coloured friends. 'There's Discus fish and a Keyhole Cichlid, which has a keyhole shape on the back of its body. The Discus are big and round and flat so when they face you they're huge and when they turn sideways they're very thin. They're incredible ultra-violet colours and they have real personalities. You can hand-feed them and when you come in the room they'll come to the glass and follow you round. I love to sit down on a beanbag at the end of the day and watch my fish. It's therapeutic, isn't it? They're alive and I'm keeping them alive. I like the responsibility.'