Gwyneth Paltrow may have a fabulous figure but it seems the actress should keep her dieting secrets to herself as doctors have hit out at the ‘detox’ kit the star is selling on her website.

The ‘cleanse’ kit advertised at £275 on her Goop website, recommends following a diet of one low calorie meal a day, two protein shakes and vitamins.

According to The Daily Mail, the chief dietician at St George’s Hopsital, London Catherine Collins has criticised the kit and the actress’ qualifications to recommend dieting tools. She said: “She is not a nutritional expert. I would not recommend it.”

It is not clear if the 39 year-old uses the kit herself but the ‘Iron Man’ star is known for her strict macrobiotic diet and even released a cook book last year with advice and recipes for healthy eating.

The actress has admitted in the past that it is not all healthy eating and that she works hard for her super-slim figure.

She told Self Magazine last year: “It's not an accident. It's not luck, it's not fairy dust, it's not good genes. It's killing myself for an hour and a half five days a week, but what I get out of it is relative to what I put into it.”

Gwyneth recently confirmed the name of Beyonce and Jay-Z's daughter on twitter as Blue Ivy after some reports had intially said it was Ivy Blue.

Gwyneth Paltrow At The Bambi Awards 2011