Adverts for junk food could soon be banned on the London Underground as part of plans to tackle childhood obesity in the capital.
London Mayor Sadiq Khan unveiled the plans, which would will also extend to other public transport, including buss and the Overground.
Mr Khan says that "bold steps" are required in order to do the right thing for young people and alleviate pressure the health service.
He said: "It can't be right that in a city as prosperous as London that where you live and the income you have can have a massive impact on whether you have access to healthy, nutritious food and your exposure to junk foodadvertising.
"I'm determined to do all I can to tackle this issue with the powers I have and help Londoners make healthy food choices for themselves and their families."
The aim of the London Food Strategy is to reduce the level of child obesity in the capital by 2028, and it will now be subject to a consultation.
Another aim of the strategy is to ban new hot food takeaways opening within 400 metres of schools.
Professor Dame Sally Davies, the Chief Medical Officer for England, said: "The evidence is clear that although it is not a silver bullet, restricting the amount of junk food adverts children are exposed to will help reduce obesity.
"Children are inundated with adverts for unhealthy food so this is a really encouraging move and a bold step in the right direction."
Justine Roberts, founder of Mumsnet, said parents would be grateful for measures that reduce "pester power".
She added: "Food manufacturers have done well in bringing down salt levels in everyday foods, making it easier for families to be healthier; it would be great if they could collectively act on sugar and fat to help parents ensure that children have a balanced diet."
London has one of the highest child overweight and obesity rates in Europe, with almost 40% of children aged 10 and 11 overweight or obese.