Union leaders are calling for the creation of 2,000 more posts for qualified school nurses in England to help deal with issues such as teenage pregnancy and alcohol and drug misuse among children.
Each of England's 152 primary care trusts should commit money to training ten new school nurses from September 2009, according to Unite.
The union's call follows the publication of the new National Child Measurement Programme figures, which revealed that a quarter of five year-olds and a third of 11-year-olds are overweight or obese.
Ros Godson, Unite's professional officer for school-aged children said: "We are appalled at this waste of money - which should be spent on helping families with overweight children - but is being frittered away in this expensive measuring exercise.
"Weighing and measuring children as they enter and leave primary school is having no beneficial effect on their size, as statistics show they are just getting fatter. The government's laissez-faire attitude is contributing to the build up of health problems, such as diabetes for future generations."
Ms Godson said school nurses were of crucial importance in supporting children and their parents or carers "throughout their child's time in school for health concerns when their child isn't ill".
"Yes, as a former school nurse, I agree that there needs to be an increase in the workforce. Anyone with half a brain would know that weighing and measuring thousands of children does nothing to resolve the problem, but just confirms the scale of it. School nurses (and health visitors) should be in a fantastic position to influence the health of our future generations, but instead are continuously bogged down trying to be all things to all people and meet government targets for new initiatives, often without the extra resources needed." - Pauline Edwards, Gloucestershire
"I totally agree with the view from Unite that mass weighing and measuring all 4 and 10 year olds in state schools is a wasteful exercise. Monitoring of a representative sample of the child population would reveal the same growth trends, at a fraction of the cost. School nurses could use their time more effectively, for example in reducing health inequalities, if they could be freed up from the task of measurement" – Catherine Gleeson, West Yorkshire
"Yes, definitely! As a school nurse, I find it impossible to give sufficient one-to-one support to parents due to lack of staff" – Anne Cleary, Bedfordshire