Chips, chocolate, fizzy drinks and high-fat foods are still squeezing out fruit, vegetables and milk in school meals services, leading nutritionists and researchers this week told a health education and home economics conference in Cumbernauld.
They confirmed the dismal picture of nutritionally deficient young people, lacking in regular physical exercise and heading for disease and illness in later life. One in five school-leavers in Glasgow is overweight,while nationally one in four girls aged 14 and 15 has a totally inadequate calcium intake that will lead to brittle bones in later life.
Annie Anderson, head of food choice and director of the centre for applied nutrition research at Dundee University, said school meals should be helping to counter "the modern malnutrition of teenagers" but were failing because meals services were under pressure to retain jobs and keep prices down.
"Caterers work on making sure there is enough food, without considering other aspects. If you looked at the meals served, you would be hard pushed to find the one portion of fruit and vegetables as a minimum.
"This is because of cost and what is deemed to be culturally acceptable and the norm. A lot of girls like to have a salad at lunchtimes but it is often not available," Professor Anderson said.
School meals were a vital part of children's diet and a "safety net", especially for low-income families. Around a quarter of a young person's daily nutritional content should come at lunchtime. But the trend towards sandwiches and snacks instead of school dinners meant it was even more difficult to meet the requirement of one portion of fruit and vegetables.
Professor Anderson said that Scotland could learn from Finland where a poor record on health had been turned around. School meals are free for all children and must meet nutritional standards. Uptake is high.
"There is limited choice but fantastic standards and meals are all served with vegetables. Fizzy drinks are banned until later in the day. Having a main meal at lunchtime puts less pressure on women to make a main meal at home," she said.
Avoiding malnutrition meant tightening school meals policies and improving shopping facilities in disadvantaged areas, Professor Anderson said. Schools also had to work on practical food skills.
Bill Gray, national officer with the Scottish Community Diet Project, said many peripheral housing schemes were "carrot-free zones". Eileen Gillan, a North Lanarkshire adviser and chairman of the Institute of Home Economics, said it was not uncommon for pupils in Lanarkshire schools to ask what a leek was.