A formal investigation has been launched into an advertisement for Protein World after a campaign asking viewers if they were "beach body ready".
The Advertising Standards Authority (ASA) confirmed it had launched an investigation to establish whether the advert breaks harm and offense rules or is socially irresponsible.
The advert has also been banned from appearing again in its current form.
The ASA said: "We've met with Protein World to discuss its "Are you beach body ready?" ad campaign.
"It's coming down in the next three days and, due to our concerns about a range of health and weight loss claims made in the ad, it can't appear again in its current form.
"Although the ad won't appear in the meantime, we've launched an investigation to establish if it breaks harm and offence rules or is socially irresponsible.
"We will now carefully and objectively explore the complaints that have prompted concerns around body confidence and promptly publish our findings."
Read more: Demonstration planned against 'body-shaming' weight loss adverts
Protein World boss labels feminist campaigners 'terrorists'
'You’re just jealous', and other common misconceptions about the advert
A mass demonstration in Hyde Park, London, was planned against the advert over claims that it was "body-shaming" and that it "aimed to make [individuals] feel physically inferior to the unrealistic image of the bronzed model".
A Change.org petition campaigning for the removal of the advert reached almost 50,000 signatures within just a few days and attracted condemnation from high profile figures such as TV presenter Susannah Reid.
Beat, the charity that supports people with eating disorders, criticised the campaign, calling it "one more example of how we are subjected daily to what we are expected to accept and aspire to as the 'body ideal"'.
Protein World’s chief executive, Arjun Seth, labelled those against the advert "terrorists".
He added that the people campaigning against the ads were "extremist, they shout a lot, these people are irrational and extremist", and said that "vandalising adverts" amounted to criminal activity.
Additional reporting by PA