Any review of school canteen guidelines must ensure canteens are not used by schools as "cash cows" to make up for any shortages in funding, NSW opposition health spokesman Ryan Park said.
Fairfax Media reported on Sunday that cash-strapped schools are using canteens to boost their budgets by as much as $50,000 a year, with some offering junk food and fizzy drinks in violation of public school canteen guidelines.
A joint working group has been established by the NSW Department of Education and Ministry of Health to explore better ways of combatting the continued sale of unhealthy food in NSW public schools.
Initial discussions have been held by the working group, which includes school principals, canteen managers and Parents and Citizens Associations, regarding the processes and scope of the review.
The education and health departments declined to provide further detail on the specific guidelines set to be reviewed, but there was an acknowledgement canteens are often run by community members who are not necessarily experts in nutrition".
Mr Park said pressure on school funding which led to canteens being used to prop up school budgets, needed to be addressed in the review.
"We need more regular checking of schools, but also more support for schools, to make sure that schools are not forced to use canteens as cash cows," he said. "I'm very concerned this forces schools to sell sugary and fatty foods at the expense of healthier foods to young people."
"I support (a review)," he said. "People who operate school canteens need to understand the responsibility they have in providing the healthiest foods to children.
"We want to endow good habits in our young people."
An education department spokesperson said schools are required to review their canteen operations every two years, and the state government's Nutrition in Schools Policy ensured canteens adhere to policy guidelines.
"A healthy canteen is one of many ways we address healthy eating and lifestyle behaviours with students. Students learn about healthy eating through the curriculum and through implementation of the Live Life Well at School program," the spokesperson said.
The childhood obesity rate in NSW climbed 7 per cent to 28 per cent in the five years to 2012, according to the Australian Institute of Health and Welfare.
