Funding for this research was provided by:
The Food and Health Bureau, the Government of Hong Kong Special Administrative Region
Received: 3 April 2020
Accepted: 23 August 2020
First Online: 4 September 2020
Ethics approval and consent to participate
: Ethics approval was granted by the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster. Parents received invitation letters for this survey, and declining parents were to ask their children to return a blank answer sheet during the survey. Student participation was voluntary even with parental consent.
: Not applicable.
: The authors declare that they have no competing interests.