Children's charities have questioned whether providing free school meals in early primary represents value for money.
Free school meals in P1-3 would bring only "modest" benefits to Scotland's poorest children, Barnardo's Scotland told the Scottish Parliament's education committee last week.
Tam Baillie, director of policy at Barnardo's Scotland, argued that the six-month Scottish free school meals pilot had been too short to evaluate the health benefits of free meals in P1-3 properly. Evidence from elsewhere was "mixed", he said. He cited research carried out in Hull, where primary pupils received free meals for three years. There they found that, while universal free meals reduced stigma for those registered for free meals, "it may not help these or other children to reach their daily recommended nutrient intakes".
Even when children were having a nutritious school meal, their eating habits had to be looked at "in the round", Mr Baillie continued.
Any roll-out of universal free school meals in Scotland should be accompanied by additional support at home and a strong research arm "to capture the real impact of providing a free school meal", he argued.
Mr Baillie's plea for further research was echoed by the representatives of Aberlour and the other children's charities giving evidence: Children in Scotland and the Child Poverty Action Group in Scotland.
A quarter of children in Scotland live in poverty, but only 15 per cent are entitled to a free school meal and only 11 per cent actually take up the offer, said John Dickie, head of the Child Poverty Action Group.
Universal free meals would remove means testing, a barrier to uptake. Children in Scotland, "unequivocally" welcomed the move.
Marion Macleod, its senior policy and parliamentary officer, said there was a need to look at the potential savings in terms of health benefits from introducing free school meals.
If money was an issue, Scotland should look to Sweden for inspiration. There, free school meals are the norm but youngsters are only offered one option, which cuts costs.
However, the Government's plans to extend free meals entitlement to all families in receipt of maximum child tax credit and maximum working tax credit from August next year would benefit "many more" families living in poverty, said Mr Baillie.