Headteachers will have to meet targets aimed at increasing the number of children eating healthy school meals, in the first initiative of its kind in Scotland.

In an effort to reverse the continuing decline in uptake of school meals and the resulting financial drain, Glasgow City Council officers are in discussions with all secondary school heads to establish "individually tailored action plans".

A report endorsed by the authority states that this will include "financial targets", fuelling fears among headteachers' representatives that heads could be held solely accountable for their pupils' diets.

Scotland's leading teaching union has also questioned whether such responsibilities are the best use of the time of senior management of schools and described it as an "unnecessary imposition".

The report also partly blames burger vans for pupils shunning healthier options and the authority is understood to be examining whether legislation could ban them from operating within a certain distance from schools.

It also proposes offering youngsters skills in food awareness, and suggests allocating an hour a week in the timetable.

Although senior figures within the council insist there will be no carrot-and-stick approach, they believe the cost implications of declining uptake cannot be ignored and that individual plans would help redress their concerns that some heads take the issue less seriously than others.

Between August 2005 and December 2006, the number of pupils eating school meals dropped from 66% of the total number of pupils to 55%. While the financial implications have not been quantified, it is understood that food worth hundreds of thousands of pounds - if not millions - is wasted as a result of declining uptake.

The report states: "In recognising the need to address the significant decline in the uptake of school meals in secondary schools and related loss of income, one mechanism to tackle this matter was to introduce individually tailored action plans for secondary school teachers, incorporating financial targets."

The council later attempted to clarify its position, claiming the agenda is "health-driven rather than finance-driven" and that if any targets are agreed they will be "meal uptake targets".

A council spokeswoman said officials were already in discussions with headteachers and that pupil councils are involved in the talks.

She said: "As a result of the local consultation process, secondary school lunch provision will no longer be the same in each school. Instead of having a one-size-fits-all approach, schools will be able to design their own healthy eating provision based on their own particular circumstances and the suggestions of their pupils."

However, many headteachers, while welcoming the opportunity to discuss the issue, believe they should not be accountable for the target.

Lindsay Roy, president of the Secondary Headteachers Association, said: "I don't think it is unreasonable to discuss with headteachers and senior managers what a target uptake might be for school meals as long as there was proper consultation.

"I don't think you should hold headteachers accountable for the target - it should be an aspiration that everyone should be working towards through a process of education and persuasion."

Willie Hart, Glasgow branch secretary of the Educational Institute of Scotland, said: "Not one teacher in Glasgow would dispute Hungry for Success is a worthy initiative.

"But I'm not sure setting abstract targets will be seen as anything other than an unnecessary imposition on schools."

The council's main opposition politicians were also less than enthusiastic.

LibDem leader Christopher Mason said it was "most unfair" to set targets and said that without the support of parents, schools were powerless to prevent children lunching at the local chip shop.

John Mason, leader of the council's SNP group, said the failure to offer a choice in school canteens was a key factor for the declining uptake.