Glasgow is confining some of its pupils to barracks at lunchtime. A "lunch at school" policy will require S1 pupils at selected schools to eat there unless they are going home for lunch with a parent or guardian.
The move is aimed at improving the take-up of school lunches and therefore the diet of secondary-age pupils.
Eight secondary schools have been chosen to pilot the one-year scheme from next August. It will be evaluated by the Glasgow Centre for Population and Health and, if successful, it will be extended to the remaining schools and other age-groups.
In tandem, the council is seeking, through its licensing board, to ban burger vans from outside the school gate.
Each of the eight pilot schools will be given latitude to implement the policy in a way that suits its own capacity, premises and resources.
Govan High plans to alter its timetable to allow S1 pupils to take lunch separately, while Whitehill Secondary plans to advertise the initiative in its school handbook next year.
Gordon Matheson, executive member for education and social renewal, said St Mungo's Secondary was particularly positive about the proposal because it could be a way of reducing territorial incidents around the school.
He said the council had invested a lot of money in school "fuel zones" to make them more attractive to pupils.
However, the introduction of stricter nutritional standards had led to a drop in the numbers opting to eat school lunches. Primary numbers had recovered, but not those in secondary.
"Youngsters voted with their feet," he told The TESS. "We are always looking for ways to try to encourage our young people to eat a hot, square meal and create good eating habits that last a lifetime.
"The indications are that healthy meals do help concentration levels of pupils in class."
As part of its strategy of winning hearts and minds in secondary, schools would be consulting widely with pupils to find menus that appealed to them, while still complying with the Scottish Government's nutritional standards.
"If you go to a fancy restaurant, you can still be offered a burger which is low in fat and high in nutrition," said Mr Matheson.
He added that the policy also had a safety aim - preventing younger secondary students from leaving the school grounds at lunchtime would reduce their exposure to traffic and other risks.
"Anecdotal evidence suggests that bullying behaviour tends to occur out of school grounds," he continued.
The policy should also reduce the amount of litter in the local community.
The council was not looking at having a "lock-in" of S1 pupils in school as some secondaries have done, he emphasised.
Pupils would be encouraged to take up a range of activities at lunchtime, including extra-curricular clubs.