The news show announced the result before the BBC’s Celebrity MasterChef Christmas Cook-Off had even aired.
Katie is one of 20 stars who have signed up for the celebrity edition of the BBC cookery show.
The MasterChef judge has lost four stone after embracing a healthy lifetstyle.
The chef and restaurateur is credited with starting London's culinary revolution in the 1960s.
“It got so bad at one point the owner of the local pub used to let me in when he was still in his dressing gown," the MasterChef star said.
The food critic said it was "terrifying" trying some of the dishes on the BBC show.
Luckily, he stopped short of plating up the charred plastic delicacy for judges John Torode and Greg Wallace.
The former EastEnders star said cooking served as a distraction from drugs.