Adverts which are likely to create body confidence issues will be banned from London's public transport network, the city's mayor Sadiq Khan said.
Concerns were raised over such adverts last year when a poster promoting protein shakes which featured a model posing in a bikini and asked "Are you beach body ready?" appeared in London Underground stations.
Many of the posters were defaced and a petition calling for their removal gathered tens of thousands of signatures.
Mr Khan has announced that from next month Transport for London (TfL) will not allow adverts on its network which could be seen to cause pressure to conform to unrealistic or unhealthy body shapes or create body confidence issues, particularly among young people.
He said: "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.
"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."
The mayor has asked TfL to establish an Advertising Steering Group to monitor its approach and keep its policy under regular review.
Graeme Craig, TfL's commercial development director, said: "Advertising on our network is unlike TV, online and print media. Our customers cannot simply switch off or turn a page if an advertisement offends or upsets them and we have a duty to ensure the copy we carry reflects that unique environment.
"We want to encourage great advertising that engages people and enhances the transport network."
TfL's advertising estate is believed to be the most valuable in the world and is expected to generate more than £1.5 billion in revenue over the next eight and a half years.
Some 12,000 adverts appear each year, including on the Tube, London Overground, DLR, trams and bus shelters.