Over recent years the fashion industry has become increasingly concerned with the health of models, with calls to stop any women who are very young or too thin from strutting their stuff on runways worldwide. Michael is completely on board with this and puts the wellbeing of the women he works with front and foremost, although he insists many models are naturally very slim - with British star Naomi a prime example.

"If a girl tells you that she's 17, and she's thin as a wisp... well, I was thin as a wisp when I was 17 and I ate cheeseburgers and pizza every day," he told Britain's Harper's Bazaar magazine. "That's kind of OK. But when I see an adult model of a certain age, unless I know that she's really taking care of herself and she's going to the gym, she's athletic and all of that, then that's when you start to wonder... some people, it's just how their body is - they're lucky. I mean, I remember Naomi Campbell carrying MCDonald's milkshakes in her purse. She used to take a milkshake out, and I'd say, 'What is that?' and she'd say, 'I just wanted a milkshake.'"

Michael has been in fashion for decades and although he enjoys the glitz and glamour of it, he warns it's not for everyone. He was friends with late designer Lee 'Alexander' MCQueen, and he's recalled the impact Fashion Week season used to take on them.

"Fashion knocks you out," he said. "It truly knocks you out. I remember, when I was at Celine, and Lee was doing Givenchy, and we'd run into each other waiting to get massages during show week. We'd be sitting in our robes in the hotel spa and he'd say, 'Are you delirious?' and I'd say, 'I'm wasted.' And he'd say, 'I'm wiped.' The endurance you need is huge. But if it's your passion, then it's never an effort really."

Another regular debate within the industry is about copycats. Many designers have called out others for seemingly being too inspired by their work - Azzedine Alaia recently drafted in lawyers following claims Roberto Cavalli had copied one of his pieces - but Michael has a fresh take on the issue.

"Back in the 1990s, when I first went to Celine, there were no Americans designing in Paris. I don't think we ever thought we'd see fashion become this borderless. Nowadays, we all swipe from each other," he said. "It was so pigeonholed before; people used to say, 'Oh those Americans, they're so practical; and the Brits, they're so quirky; oh the French, they're elegant...' It was all these cliches, and if you're actually fluent in fashionista then you're learned to take what you need from each and leave the rest behind."