An article on Gwyneth Paltrow's wellness advice website Goop encouraging readers to try and reach their "leanest liveable weight" has been called "dangerous" by scientists.
They say the message is open to problematic interpretation and could encourage eating disorders like anorexia in young, susceptible girls.
The article, titled "Busting Diet Myths", includes an interview with Dr Traci Mann, in which she says people should attempt to be at their lowest "set range."
She describes this as a weight which a generally healthy person would be able to maintain.
However, the article has now been blasted by Dr Giles Yeo, from Cambridge University, who says the article is "irresponsbile" as it suggests people should be "as skinny as possible without dying."
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Giles, who has presented Trust Me, I'm A Doctor on the BBC for 20 years told The Daily Mail, "This is a dangerous suggestion, as many people will take it to mean they should be as thin as possible.
"It is irresponsible because the idea is so open to misinterpretation, especially for young girls susceptible to eating disorders.
"The problem with many of Goop's recommendations is that they are not based on science, but pseudoscience."
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Yet Traci Mann has now hit back at Giles' claims, saying the article is "specifically about not dieting" and "not doing anything unhealthy or extreme".
She adds that "leanest liveable weight" means being your leanest weight without engaging in "strict dieting or unhealthy behaviour."
Gwyneth previously revealed to Shape that she does "one good cleanse a year" to "detox" her body. However, she regularly indulges with "a glass of wine, maybe a baguette dripping in cheese, some fries" and on holiday she will eat "what I want — and there’s no exercising, either”.