Simon Cowell "binges" on fish and chips, one of his close co-workers claims.
The music mogul famously has multivitamin injections to help stay healthy but Amanda Holden - who is a judge alongside Simon on 'Britain's Got Talent' - says he also can't resist a calorific meal now and again.
Holden, above, has just released her autobiography.
Speaking about her autobiography to new! magazine, she said: "I have so much respect for Simon. He's my friend. But there are some fun bits about how he likes to binge on fish and chips and how he has multivitamin injections. I tried one once while drinking a glass of champagne and it felt like I'd had eight gin and tonics!"
Meanwhile, the 42-year-old actress is confident that the 'X Factor' boss - who is expecting his first child with his lover Lauren Silverman - will make a brilliant father because he will be forced to change his ways for the sake of his little one.
She explained: "I don't want to sound patronising when I say that I feel very proud of him for embracing fatherhood. I know it's going to change him for the better. He's a natural."
However, Amanda - who has children Lexi, seven, and 21-month-old daughter Hollie with husband Chris Hughes - is slightly envious that Simon won't have to suffer with sleepless nights when the tiny tot arrives because he'll have a team of nannies on hand to help out.
She said: "He won't have sleepless nights. He will have a team of people around him - there is no denying that."