A wife, four daughters, three dogs, five chickens… the 26-year-old actor carries the life experience of someone twice his age.

Anticipating Mr Aaron Taylor-Johnson’s entrance at a diner in Eastside LA is rather like waiting for a blind date. One never knows exactly what will walk through the door. With 20 years of acting under his belt, at 26, he’s already been through more remodels than most. When we last met, in 2014, he was bench-pressed to near marble for his Eastern European superhero Quicksilver in the Avengers: Age Of Ultron. I have bumped into him in media res metamorphosis between Anna Karenina’s Count Vronsky (flaxen-haired and moustachioed), an avenging super-nerd in the Kick-Ass series (somewhere under an avalanche of curls) and a teenage Mr John Lennon, with a cigarette behind one ear, around the time of Nowhere Boy, directed in 2009 by British film-maker Ms Sam Taylor-Wood, now his wife and the mother of his two daughters.

The experience of Nowhere Boy meteorically altered the course of the former Mr Johnson’s life and hurtled him towards responsible manhood. He became a father at 18 and was married at 22, taking on two stepdaughters and a new surname (he and Ms Taylor-Wood both changed their names to Taylor-Johnson). Since then, he has approached his family life with a greater intensity than his roles. At home, he plays the lead in a kind of Hollywood domestic idyll, tending to his own vegetable garden and chicken coop, popping down to the organic butcher, cooking fresh eggs from his chickens for daughters Mses Wylda Rae, six, and Romy Hero, five, and doting on Ms Taylor-Johnson, as can be seen on her Instagram account. For the record, she is 23 years his senior.

He is now teetotal, following a three-month intoxication regime last year to play Texan psychopath Ray in Mr Tom Ford’s Nocturnal Animals, after which he embarked on “clearing” himself with the aid of a shaman, and then took up heavy Pabst Blue Ribbon beer consumption to play a military sniper in his upcoming film The Wall. As Ray, he spent much of 2015 resembling a homeless brother of the Kings Of Leon, and he has just completed a six-month Nocturnal Animals tour of duty for awards season in an immaculately steam-pressed range of Tom Ford suits.

When we meet today I have a suspicion that he might have shape-shifted again. He chuckles sweetly when I confess all of this, after he saunters in like a 1950s off-duty army veteran in khaki combat pants, a motorcycle-print short-sleeved shirt open over a white vest and dog tags. “The worst was when my daughter had just finished kindergarten and she had to make a storybook of the year with photographs of herself,” he says. “Each picture was her, mummy and some different bloke every time: short hair, long hair, moustache, no moustache, bearded, scrawny, soldier build. It was like, ‘Who in the hell is that?’”

If Nowhere Boy was the film to have the greatest impact on the former Mr Johnson’s personal life, then Nocturnal Animals has been the one to redefine his career. With its release in late 2016, Mr Taylor-Johnson graduated from boy wonder to mature method man. His homicidal rapist Ray is the depraved heart of the film, as magnetic as he is sadistic, as potent as he is vilely misogynistic, the kind of disturbing and compelling viewing that Travis Bickle offers us in Taxi Driver. It is a shame that he was overlooked for an Oscar nomination, and he also lost out on a Bafta to Mr Dev Patel. But he is not in the least bit disappointed. He has the bouncy demeanour of a man who can finally step off his first awards season juggernaut. “There is a sense of relief,” he says. “I’m not ungrateful, nor is this spiteful. It’s just that I can’t handle all the attention.”

Award ceremonies “absolutely terrify” him. At the Golden Globes, he gave a refreshingly un-schmoozey speech in his prosaic Buckinghamshire accent, thanking his wife “for putting up with me – I was not very pleasant in this role”. Mr Taylor-Johnson hates talking about himself. He’d rather show me an iPhone video of his daughter doing an ethereal dance to Queen’s “Another One Bites The Dust”, or a photo of Ms Taylor-Johnson performing an advanced yogic back-bend-to-headstand against the wall. He is gentle and unassuming, less of a lone wolf than a pack animal who is more at ease within his family or an ensemble cast. It’s hard to believe that such an unhinged performance could emerge from such a reserved man, but then just look at Mr Robert De Niro.

Mr Taylor-Johnson might be capable of live-wire performances, but he is deeply earthed, an unlikely mix of youthful rawness and grounded emotional maturity, a sensitive soul in the powerful body of a marine. In The Wall, he plays a US Army spotter who is hemmed in, quite literally with his back against a wall, by an unseen Iraqi sniper after his own sniper team partner (Mr John Cena) is shot down. Directed by Mr Doug Liman (The Bourne Identity), the single-location action thriller promises to be psychologically taut, with Mr Taylor-Johnson holding down most of the film single-handedly.

The preparation was typically intense. Throwing himself ferret-like into research on post-traumatic stress disorder, the actor tapped up friends with army connections, including American Sniper’s Mr Bradley Cooper, who hooked him up with war veteran Mr Jacob Schick, one of the founders of 22Kill, a support group for ex-serviceman (named after the estimated 22 suicides a day of US veterans between 1999 and 2010). He subsequently flew out to a 22Kill event in Boston. “These guys are the most down-to-earth, grounded people,” he says. “And some of them have been to hell and back. It was the most moving thing to [witness]: men who you think of as very masculine, military men being open about their struggles with PTSD. Some have got to the point where they’ve put a gun to their heads, a lot have had suicidal thoughts, but the camaraderie, the brotherhood, the banter…”

Mr Nick “The Reaper” Irving (famed for his 33 confirmed kills in his first three months in Iraq) is “one of my best mates now. He’s a super-cool dude, a genuine sweetheart.” During his research, Mr Taylor-Johnson also won the support of Nobel Prize-winning war photographer Ms Lynsey Addario and Ms Jane Horton, a veterans and family advocate, whom he met by chance while practising at a rifle range. Her husband, Mr Christopher Horton, turned out to be a sniper who was killed in action in Iraq, and heavily influenced his character’s profile. In addition, he spent time with trainee snipers at Fort Chaffee in Arkansas. “Not many of them make it through the six-week training,” says Mr Taylor-Johnson. “Out of 30, say, only 10 graduate. One of the shots was 1,356m away – that’s almost a mile to hit the target. You’ve got to learn about the wind and the earth’s axis. All the technical stuff is pretty amazing.”

Mr Taylor-Johnson’s weight gains are an art form in themselves. He put on 13kg to bulk up to 85kg (187 pounds), with a specific military physique in mind. “It was eat and gym, eat and gym,” he says. “But it wasn’t the same as for The Avengers: Age Of Ultron, which was eat clean, high-end protein, so you look healthy. It was eat shit. I was eating 4x4s at In-N-Out Burger at 11.00am. Sometimes I pass In-N-Out now and I get that 4x4 feeling.” As with Ray, Mr Taylor-Johnson spent two months living and breathing his character, even smelling authentic. “I was drinking crate-loads of cheap beer,” he says. “Chewing ‘dip’ tobacco, that was the worst thing: Copenhagen’s Wintergreen. It builds up the saliva in your mouth so that you spit. Then you have this terrible, rancid kind of breath. My wife wasn’t very pleased with that one either.”

Mr Taylor-Johnson’s acting modus operandi seems to be based on a kind of binge-and-purge cycle. In order to embody the loathsome Ray, he chain-smoked, chain-cracked beers, chain-watched documentaries about serial killers and abstained from cutting his fingernails for three months to “feel toxic inside and out”. He was reluctant to bring such dark energy near his wife and children. Once filming wrapped, there was a three-month-long exorcism of Ray. “When you take on that kind of chemistry and psychological damage, you end up carrying it with you, and you can’t quite get rid of as much as you’d like,” he says. “So I need to detox. And I see these sort of special gifted shaman women, who do reiki and needle work [acupuncture]. I’ve had a bunch of needles in my eyeballs before. I had it done after working with Oliver Stone [as a drug dealer in Savages].”

After all the drinking for The Wall, he went teetotal in January. “I’m not in AA or NA or any of those things,” he says. “I can just stop.” Even without an addictive personality, these six months of yo-yoing between extremes is one of the reasons he takes on only one project a year, allowing “for a good two to three months on the way out of a character. Then the rest of the time I do more earthy things like gardening or cooking or just being with my kids.” At the moment, he’s going through his Japanese culinary period and gets rather animated when talking about his donabe ancient clay cooking pots.

“I make fresh seaweed stocks you cook in the rice with toasted sesame oil and sake,” he says. “And you can steam eggs in it while you cook and crack them in. Then I add the daikon sprouts. Presentation for me is everything. I go to the nth degree.” He has also landscaped his allotment on the hillside of their garden. “I like my world to be calm,” he says. “When you deal with this lifestyle [it can drive you crazy]. That’s why I see half of my friends go off the rails. You can really burn it at both ends, get into drink and drugs.” It is rare for an actor who began working at the age of six to be so level headed.

Mr Taylor-Johnson grew up in Holmer Green in Buckinghamshire. Aged six, he enrolled at stage school to study drama, tap, jazz dance, acrobatics and singing. Three years later, he was treading the boards in the West End as Macduff’s murdered son opposite Mr Rufus Sewell’s Macbeth. He left school at 15, and went to LA on a tour of Hollywood agents. He was cast in The Illusionist in 2006, and in Mr Matthew Vaughn’s Kick-Ass two years later; he was subsequently nominated for the Bafta Rising Star award. Then came a “self-destructive moment”, a kind of blow-out session of his youth all packed into two short years before he was 18. “I just went a bit fucking mad,” he told me in 2014 during our interview about Godzilla. “I blew a shitload of money, and had two years that I cannot even remember. I mean, you have to get everything off your chest before you can move on, right? Because if I hadn’t done that then, I’d be breaking down now. I wouldn’t be able to raise a family, or be in control, or feel responsible enough to do what I do.”

Mr Taylor-Johnson’s friends call him Benjamin Button, the man who aged backwards. “I get more fulfilment from being a father than I do from being an actor,” he says. “I’m still constantly wanting to give it up.” He and his wife alternate projects while the other stays at home. For Fifty Shades Of Grey, which she directed, the whole brood decamped to Canada with her. She recently executive produced and directed two episodes of the Netflix psychological thriller series Gypsy. Towards the end of our conversation, he reveals the Taylor-Johnsons are working together again. There’s a dance piece and they’ve bought the rights to a mystery book, with a mystery film that might be at Cannes this year.

He admits that, in addition to “a wife, four daughters, two female dogs and three female chickens”, he also has his own female energies. “I’m happy to say I’m a feminist,” he says. “Being a feminist is just believing in equal rights. Man, woman, gay, straight, black, white – we’re all in it together.” Mr Taylor-Johnson is currently in the process of printing out thumbnails of all the posters from the global women’s march in January to decorate the family bathroom. “When they are young women, they’re going to be ready,” he says of his daughters. “I mean, their mum is one of the strongest, most independent women I know. A role model.”

Note to reader: a male feminist is immeasurably attractive to the female species. This one also gives flowers. “Mamma got a dozen on Valentine’s Day,” he says. “The other girls got half a dozen each.” I posit that he could probably write an instruction booklet on How To Keep Women Happy. He looks a little befuddled. “I don’t really analyse our relationship,” he says. “I just know that it works. I just feel secure and loved and safe. We have this very deep connection. We’re just in synch.”

The Wall is out in May