Simon Cowell is on the ''Eric Cowell diet''.

The 59-year-old music mogul recently made a number of lifestyle changes and has cut out dairy, sugar and gluten and joked his new healthy-eating regime has been inspired by his and Lauren Silverman's five-year-old son.

He told 'Extra': ''New diet. 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.' I'm thinking, 'What about alcohol?'

''And he said, 'Maybe not quite as much as you had before.' And I did it and I stuck to it and it's easy.

''Apart from ice cream, [Eric] actually likes water, eats all his raw vegetable. I'm on the Eric Cowell diet.''

The 'America's Got Talent' star is devoted to his son.

He gushed: ''He's a sweetheart.''

It was recently revealed Simon had shed 7lbs on his new diet.

A source said: ''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.''

And though the 'X Factor' boss is missing a few of his favourite treats, he feels much better for making the changes.

The insider added: ''He's found it really tough to cut out a lot of things he used to love eating, like sausage rolls.

''But he can't believe the change it's had in such a short space of time.

''He's looking and feeling great at the moment, the best he has in years. He has a real spring in his step, which everyone around him has noticed.''