Education and Training Minister Joy Burch will launch the new ACT Public School Food and Drink Policy on Friday.

Under the policy, food will be placed into green, amber or red categories depending on nutritional value, with the traffic-light system to be applied to the sale of all food and drinks in school canteens and to all public school activities and events in Canberra.

There will be some exceptions for events such as school fetes or birthdays.

The policy also prevents sugary drinks from being sold in public school canteens and bans vending machines on public school sites.

School staff will also be encouraged not to eat "red" or low nutritional value food or drinks in view of students while principals will be responsible for ensuring "red" food or drinks are not used as rewards or incentives for student learning.

Ms Burch said the government was committed to improving access to healthy food and drinks in ACT schools.

She will announce a series of fact sheets developed to support the food and drink policy and ensure it is consistently implemented across schools.

The fact sheets - which were developed following community consultation last year - include resources for canteens and parents about healthy lunchboxes and how to eat fresh.

Ms Burch said the policy was part of a range of initiatives to improve healthy eating at ACT schools.

"Our attitudes towards food are formed during childhood so it makes sense that once a child begins school, the school environment plays a role in influencing their food preferences," she said.

"This new policy promotes a consistent, whole school approach to healthy food and drinks and will help develop healthy eating and drinking habits from an early age."

ACT Council of Parents and Citizens Associations vice-president Hugh Boutler said the new policy provided support to parents looking to reinforce the importance of healthy eating to their children.

The new policy follows the introduction of a new curriculum teaching ACT students about good nutrition, healthy eating and even food advertising in September last year.