Students' perceptions of school sugar-free, food and exercise environments enhance healthy eating and physical activity.

Objective: The objective of this study was to examine the relationships between students' perceptions of their school policies and environments (i.e. sugar-sweetened beverages (SSB) free policy, plain water drinking, vegetables and fruit eating campaign, outdoor physical activity initiative, and the SH150 programme (exercise 150 min/week at school)) and their dietary behaviours and physical activity.

Design: Cross-sectional study.

Setting: Primary, middle and high schools in Taiwan.

Participants: A nationally representative sample of 2433 primary school (5th-6th grade) students, 3212 middle school students and 2829 high school students completed the online survey in 2018.

Results: Multivariate analysis results showed that after controlling for school level, gender and age, the students' perceptions of school sugar-free policies were negatively associated with the consumption of SSB and positively associated with consumption of plain water. Schools' campaigns promoting the eating of vegetables and fruit were positively associated with students' consumption of vegetables. In addition, schools' initiatives promoting outdoor physical activity and the SH150 programme were positively associated with students' engagement in outdoor physical activities and daily moderate-to-vigorous physical activity.

Conclusions: Students' perceptions of healthy school policies and environments promote healthy eating and an increase in physical activity for students.