Here are some links to help you with your research:

https://kidshealth.org/en/kids

http://www.stylecraze.com/articles/junk-food-vs-healthy-food/

http://www.livestrong.com/article/410164-advantages-disadvantages-of-healthy-food-vs-junk-food/

https://healthy-kids.com.au/school-canteens/

http://www.education.vic.gov.au/school/principals/management/Pages/canteen.aspx

https://www.health.gov.au/internet/main/publishing.nsf/Content/5FFB6A30ECEE9321CA257BF0001DAB17/$File/Canteen%20guidelines.pdf

https://www.healthykids.nsw.gov.au/

http://www.activehealthykidsaustralia.com.au/