Should secondary pupils under the age of 16 be locked in school grounds?

Minister calls for lunchtime lock-in at schools to stop rush for chippie (link via guardian.co.uk) The proposal comes as damning new research reveals the extent to which children pass through school gates to buy large quantities of food that is high in fat and sugar. Some pupils left school to buy junk food more than 11 times a week. With soaring numbers of children now dangerously overweight, Brennan said one answer was to keep millions of pupils inside the gates. 'Some schools have a stay-on-site policy for 11- to 16-year-olds but lets the sixth form go off-site. I'm very strongly supportive of that approach. I would like to see more schools operating some sort of stay-on-site policy because its advantages are shown not just in improved uptake [of healthy school lunches], but also improved behaviour and community relationships.' But any plans to lock children in were attacked as Orwellian by parents yesterday, while headteachers argued that it was not possible to police pupil movement Personally, I agree with keeping pupils inside the gates during the school day. That was the rule when I went to (an American) High school and that's the rule at the secondary school my eldest son attended and my youngest son is still a pupil at. The sixth-formers are allowed to go off-site and that makes sense to me - they are treated as adults and deserve the right to leave the school grounds when they want to. I'm not sure about literally locking the school gates though. It should simply be a rule and enforced. If kids sneak away, they should be punished. It's not just about their diet, but their safety. They are children (11- to 16-year-olds) so they need to be obeying the school rules and certainly not roaming around away from the school during the lunch hour. What do you think? Do you think kids in secondary schools should be allowed to go off the school grounds during their lunch time? Or is it too much of a nanny-state idea?