The article, especially the headline, is just click bait for the gullible.
As already noted, "public transport" hasn't been clearly defined.
It does, of course, include air travel, sleeper trains, cross Chanel ferries and many other long journeys where the passengers need to eat.
Any journey over, say, three hours is likely to require food for the average traveller.
There is also no explanation about how preventing adults from eating on a journey will tackle childhood obesity.
IMHO the problem is the type of highly processed food easily available which encourages over eating.
However to change this would require taking on the food manufacturers and retailers who are a massive and influential lobby group.
Governments these days like to offload responsibility to 3rd parties so they don't have to do anything themselves.
Childhood obesity?
Make the drivers on busses a new police force, and if it doesn't work it is their fault.
I wonder how they are going to enforce this on the newer trains where there is only a driver, no guard?
Zero hours contract food police?