Despite reports that the future princess has gone on the strict no-carb Dukan diet, it's actually her mother, Carole, who is following the plan.
The elder Middleton, who runs the party planning company, Party Pieces, told UK's Sunday Times in October that she had just started the diet. "I've been doing it for four days and I've lost 4 lbs.," she said at the time.
The strict diet, created by nutritionist Pierre Dukan, consists of four stages, during which followers eliminate all carbohydrates, than slowly phase back in healthy starches.
And while her mother has had success with the diet, Middleton hasn't needed to go so far, sources say. "She's just an active individual," the source says.