Music mogul Simon Cowell jokes he will release a fitness DVD with "Britain's Got Talent" co-judge David Walliams after losing 9 kgs (20lbs).

Appearing on show "Lorraine" this week, Williams, who says he's also "lost a tiny bit of weight", said: "Are you doing a workout video?"

Cowell laughed: "I could do one with you, yeah."

Their comments come after the 59-year-old media mogul was forced to deny claims he had a gastric band fitted to help with the weight loss, reports femalefirst.co.uk.

He said: "People have said: 'Oh, he's had a gastric band fitted' - but I haven't. If I had, I would admit to it. This diet is all about what you put into your body."

Instead, Cowell listened to an expert as a doctor sought to change his "appalling" diet.