Obesity is an environmental issue not a disease. Children growing up in the 1950s and 1960s were not obese. Virtually all people over 60 (and many younger) remember walking to infant school without an adult. Most travelled unaccompanied from the age of five after being taken for a couple of weeks by a parent. Children would also be able to run around in their own street and go on errands at this age. In other words, they had daily healthy exercise at no cost in money or time to the government and their parents.
Since then, the car has increasingly dominated residential roads, which are therefore more dangerous. Parents sensibly react to the increased danger and keep their children penned in. This unhealthy trend predates mobile phones or computer games.
The full article by Rob Wheway is available here.