Britney Spears staying away from coke

London: Britney Spears is staying clear of donuts and coke on the set of the US X Factor.

The ‘Toxic’ hitmaker has been on a strict diet to get in shape for her job on the judging panel.

“Britney has been on an extreme diet and exercise regime. She has been cutting out carbs and replacing meals with juice drinks,” the Sun quoted as source as saying.

“She was doing several hours of exercise a day before the launch and is trying to stick with the regime,” the source added.