CONFINING pupils to school grounds at lunchtimes may violate their human rights, teachers have warned.
The Scottish Secondary Teachers' Association (SSTA) said the measure, to stop youngsters eating junk food, could create conflict.
From August pupils at eight Glasgow secondaries will be banned from leaving school grounds. But teachers have said it could spark an angry backlash from pupils and parents.
Jim Docherty, SSTA acting general secretary, said: "Any parents who wish their children to be allowed out of school at lunch breaks should have those wishes respected.
"We live in an era of continued argument on the basis of "human rights".
"It is better that relevant authorities recognise this and do not attempt to introduce 'lockdown' mechanisms except with the full support of all included."
Those in the pilot will be All Saints Secondary, Castlemilk High, Govan High, Lochend Community High, St Mungo's Academy, St Thomas Aquinas, St Paul's High and Whitehill Secondary.
If successful, the scheme will be rolled out to all first year pupils in the city's schools.
Obesity is a growing problem in Scotland, with one in five boys and more than one in seven girls under the age of 15 classed as obese.
New government directives have made school meals more healthy, but take-up, particularly in secondary schools, has been low as many still head to shops or burger vans to buy junk food.