The Mayor faces two issues following his decision to have more restive rules on the type of ads that will appear on tube and buses.
First is the principle that ads should not encourage impossible or unachievable body images. I think that many Londoners will agree with Transport for London and our new Mayor.
These are very public places, it is not as if we can turn the page or switch channels, the ads are right there in front of us on the platform or on the bus.
Ads like the recent Jack Wills catalogue of youngster in underwear may be a good example of the type of images that may worry large sectors of the travelling public. I would strongly argue that media owners, like TfL are at liberty to have their own special standards about which ads they will sell space to.
Read More: Khan to ban unhealthy body image advert
But, secondly there is the need to make sure that decisions about individual ads are made based on fact. Here I think many Londoners will agree with the Advertising Standards Authority.
A recent "Beach Body Ready" ad featured a model in it who is not a child or underweight or ill. Unlike the recently banned Yves Saint Laurent ad where the ASA ruled that "the model appeared unhealthily underweight in the image and concluded that the ad was irresponsible."
Advertising is an important source of income for TfL and totals £1.5 billion which is reinvested in improving infrastructure and subsidising travel cost for Londoners. The mayor and TfL must be careful not to send out the wrong message, alienating advertisers and causing them to spend their ad money elsewhere.
Of course, they must also avoid the trap of banning ads simply because those of us who are overweight want to bury our heads in the sand and pretend that fat is the new normal.
The new rules will need to be applied with sensitivity, helping Londoners and our visitors have a comfortable travelling experience in every respect. Avoiding the charge of censorship will be the challenge.