Simon Cowell has radically overhauled his diet.
The 59-year-old music mogul sought advice from a nutritionist earlier this year after feeling tired and sluggish, and now he's cut out gluten, dairy and refined sugar, he's shed 7lbs and feels much more energetic.
A source told the Daily Mirror newspaper: "Simon was feeling a bit run down, so someone suggested he see a specialist about food tolerances. The specialist revealed he is allergic to a few everyday things which had been making him tired.
"As a result, he has cut out lots from his diet and the impact has been almost immediate. He has loads of energy."
But Simon - who has five-year-old son Eric with girlfriend Lauren Silverman - hasn't found his new diet easy to adjust to.