Adverts that are likely to cause people to have "body confidence issues" will be banned from London's public transport network from next month, mayor Sadiq Khan announced on Monday.
The new rules will apply to the estimated 12,000 adverts that appear each year on the network run by Transport for London (TfL), a local government body, which includes the Underground, buses, trams and trains.
TfL's advertising estate is the most valuable in the world and is expected to generate more than £1.5 billion (S$2.89 billion) in revenue by the end of 2025, the mayor's office said in a statement.
"From next month, TfL will not allow ads which could reasonably be seen as likely to cause pressure to conform to an unrealistic or unhealthy body shape, or as likely to create body confidence issues, particularly among young people," the statement said.
Khan, a member of the opposition Labour party who was elected last month, said he was moved to act out of personal experience.
"As the father of two teenage girls, I am extremely concerned about this kind of advertising which can demean people, particularly women, and make them ashamed of their bodies. It is high time it came to an end," he said.
"Nobody should feel pressurised, while they travel on the Tube or bus, into unrealistic expectations surrounding their bodies and I want to send a clear message to the advertising industry about this." An advert for Protein World slimming shakes, showing a slim woman in a bikini alongside the words "Are you beach body ready?", caused a furore when it appeared on the Underground last year.
There was outrage on social media and the company said it even received a bomb threat. More than 300 people complained to the Advertising Standards Authority, but the watchdog rejected claims the advert was offensive or irresponsible.