You could be forgiven for not recognising the face (or rather the body) in Emporio Armani's latest underwear campaign.

The stylish black and white photos show a torso that is suitably chiselled, immaculately groomed hair, a dash of designer stubble and, of course, the brightest - and tightest - white pants.

DJ Calvin Harris, 31, has undergone a startling transformation in recent years; his once skinny frame replaced with a rippling physique that could put many a male model to shame. When images from the glamorous shoot were released, they quickly went viral.

Wow! What happened to Calvin Harris? The superstar DJ, said to be worth £44million, is the star of a new underwear campaign by Armani... but he wasn't always to easy on the eye

Pre-muscles: The 31-year-old Scotsman from Dumfries, pictured here in 2007 and 2009 respectively, once favoured the skinny-boy look with longer locks and paler skin

Swoon: The DJ has all but given up alcohol and has a regular exercise routine that has honed his body...he joins David Beckham and Cristiano Ronaldo as one of Armani's boys in briefs

Harris, said to be the world's richest DJ with a personal wealth of around £44million, says his enviable six-pack is down to largely ditching alcohol - he hasn't drunk for a year - and a dedication to working out.

The pop star, from Dumfries in Scotland, seems to be enjoying what has become known as the 'Gary Barlow effect', where men get more attractive as they advance in years.

In the boy band's heyday, the Take That star was famously the least attractive member, something he himself admitted to - and trailed in the wake of his more athletically-blessed peers when it came to fan mail.

Yet in the group's renaissance, Gary has captured the hearts of a new generation of fans. Following a strict diet, the songwriter has shed the pounds that once dogged him and managed to keep the weight off. A smart haircut, light beard and personal stylist have seen his popularity soar.

After the weight loss, he said: 'I’ve just not got the sort of body where I can pick and choose what I eat. I’ve got to go for one thing and stick by it. So I’ve tried not to have sugar and caffeine, etc, and it’s boring, it’s really boring.

'But it works for me. The result is that I feel good.'

‹ Slide me › Better second time around: Gone is the peroxide hair of Gary in the first incarnation of Take That...replaced by a gentle quiff, light tan and more slimline figure

‹ Slide me › Not so gorgeous George: On the set of Nineties television show Baby Talk, Mr Clooney sported bouncy hair and double denim but has grown older gracefully, and bagged a beautiful lady to boot. The actor is pictured earlier this year with new wife Amal Alamuddin

Not always Prince Charming: Harry's flame-red hair, (captured left at Eton College in 2003) has softened with age and a career in the Army has ensured his slight physique is a thing of the past

Bleached hair, two earrings and a shiny jacket: The fashion disasters of a young Justin Timberlake, pictured left in 1997 and, right, spotted last month looking positively debonair in New York

Not even the thinking woman's crumpet... Hugh Laurie took a while to shine but a hit series, House, in the US transformed the way the opposite sex viewed him

Channelling Malfoy? An early shot of actor Daniel Craig (left) feels a long way from 007. Right, the actor in his more familiar guise at the press call for new Bond film Spectre in December last year

He's not the only male celebrity to have improved with age however. Universal heartthrob George Clooney's legion of adoring fans will mostly agree that the Hollywood actor/director has matured like a fine wine, suiting a smattering of grey hair much more than the more bouffant look that he sported in the Eighties.

Other stars offering hope to mere mortals fearing their middle years include Hugh Laurie, who became an unlikely desirable as the front man of US television hit House.

The latest incarnation of James Bond, Daniel Craig, has definitely become more attractive as he's clocked up more miles. Photos of the actor in his 20s show badly-dyed blonde hair and none of the super-fit physique that 007 fans have lusted over.

Chart-topping makeover: Fear of appearing on television on a Saturday evening, on BBC show The Voice, propelled The Kaiser Chiefs lead singer, Ricky Wilson, into re-thinking his look

Hirsute suits you, sir: David Beckham (pictured left in 1999) has changed his looks many times but most will agree his brooding, bearded look since retiring from football is his best

‹ Slide me › So much better blonde: Ryan Gosling sporting darker hair and a fresher face back in 2002 and looking much more delicious last year at the Cannes film festival in 2014

The fashion designer Marc Jacobs hasn't been shy in showing off his gym-honed body in recent years but wasn't always quite so muscular; photos of the designer from his pre-work out stage reveal unkempt hair and an unremarkable physique.

Younger stars who, like Calvin Harris, seem to have grown into their bodies as they reach their thirties include Justin Timberlake. The former N-Sync singer's youthful looks, complete with an earring in both lobes, might not have attracted the attention of now-pregnant wife Jessica Biel.

And Prince Harry might not have enjoyed so much female attention without his Army training routine. Photos of the prince as a teenager, dressed in Eton gowns, reveal a slim frame and a redder tint to his hair.