Dieticians have condemned a diet popular with the stars, and warn it could actually impede weight loss in the long-term.
Brad and Jen are said to follow the Atkins diet
Over 97% of UK state registered dieticians surveyed condemned the Atkins Diet, saying it gave "bad dietary advice".
The diet, credited for keeping stars like Jennifer Anniston and Courtney Cox Arquette slim, recommends restricting major food groups in the diet.
It advocates a high protein and fat intake, but the severe restriction of carbohydrates, such as bread, pasta and other wheat products.
But dieticians say the diet should, but does not, advise people to seek medical advice before trying it.
And they say that the Atkins diet contradicts all government advice to maintain a healthy and well balanced diet.
Such a strict unbalanced diet will inevitably cause your body to suffer
Diets like the Atkins diet are often high in meat proteins and experts have warned that they could overload the kidneys.
And women of childbearing age have been warned not to follow high protein, low carbohydrate diets as they could be risking the health of their unborn babies.
Those following the diet are allowed to eat unlimited meat, eggs, fish and shellfish.
Catherine Collins, state registered dietician at St Georges Hospital, London, said although there was short term gain that there could be long term health effects.
"Over the last few years there has been marked increase in the number of people eliminating certain food groups from their diet.
"Many of these people have admitted to following celebrity-endorsed diets frequently reported in the media, such as The Atkins Diet.
"While such diets may appear to work in the first instance, persisting with such a strict unbalanced diet will inevitably cause your body to suffer, and possibly impede your ability to maintain your weight loss in the long run.
"It is really important for people to consult a qualified health professional such as a GP or state registered dietician before eliminating entire food groups from the diet."