The Department of Education has stated there is nothing it can do to prevent schools installing vending machines that offer unhealthy snacks to pupils.
A spokesperson from the government said it is a matter for each school to draw up guidelines for the food that is available on its premises, the Irish Examiner reports.
However, Dr Cliodhna Foley-Nolan of Safefood Ireland said there is a problem with this approach due to a conflict of interest.
As schools obtain income from the food sold through vending machines, it is tempting to offer popular but unhealthy products, the expert noted.
The implementation of national guidelines for vending machine contents in post-primary schools was also recommended by the report of the National Task Force on Obesity in 2009.
Despite a study by the Irish Heart Foundation revealing 92 per cent of establishments believe there should be a code of practice on the provision of these machines, only 36 per cent of second level schools have healthy eating policies in place.
Recently, the Growing Up in Ireland report noted over a quarter of nine-year-olds are overweight, which could lead to increased health risks in later life.