Britain’s Got Talent judge Simon Cowell showcased a slimmer figure during the instalments of the hugely popular reality show this year.

Sitting beside his fellow panellists Amanda Holden, 48, Alesha Dixon, 40, and David Walliams, 47, the 59-year-old music mogul sported a typically unbuttoned white shirt throughout the series.

Despite his usual choice of outfit, the reality telly boss’s recent weight loss didn’t go unnoticed by presenters Ant and Dec, with Simon dubbing his recent ‘diet’ as the reason.

Simon recently spilled the beans on the secret behind his trimmer figure, revealing, “I went to see this guy who’s very well-known. And he said to me, after doing some blood work, ‘You can’t have red meat, dairy, sugar, bread or gluten.’”

MORE: Alesha Dixon reveals she’s expecting second child as she debuts baby bump on Britain’s Got Talent

Speaking to Extra the X-Factor front man confessed his first thought was, “What about alcohol,” before laughing and continuing, “He said, ‘Maybe not quite as much as you had before.’ And I did it and I stuck to it and it’s easy.”

The father-of-one even went on to claim he was following the eating habits of his five-year-old son, Eric.

He said, “Apart from ice cream, he actually likes water, and eats all his raw vegetable. I’m on the Eric Cowell diet.”

A source recently told the Daily Mirror Simon has “lost half a stone’ thanks to his new healthy lifestyle and has had ‘a real spring in his step”.

The insider claimed that he first began the diet overhaul after he visited the doctors, where they explained that he was feeling tired due to an intolerance of certain foods.