Objective: To describe the prevalence characteristics and trend of malnutrition among primary and secondary school students in Zhejiang Province from 2008 to 2021, so as to provide scientific references for targeted interventions on malnutrition among children and adolescents. Methods: Based on the National Student Common Diseases and Health Influencing Factors Surveillance Project, 81 228 primary and middle school students aged 9-17 from Zhejiang Province were recruited for a questionnaire in 2008, 2014 and 2021, with stratified cluster random sampling method. Malnutrition was determined by Screening for Malnutrition in School aged Children and Adolescents. The Kruskal-Wallis test was used for non normally distributed data, and the Chi square test was used for categorical data. A trend Chi square test analyzed detection rates across different years. Results: The prevalence rates of malnutrition, stunting, mild wasting, and moderate to severe wasting among primary and secondary school students in 2008, 2014 and 2021 were 12.0%, 6.6%, 6.0%; 1.2%, 0.5%, 0.3%; 6.0%, 3.9%, 3.6%; and 4.7%, 2.2%, 2.2%, with an overall declining trend ( χ 2 trend =532.73, 181.43, 161.24, 240.38, P <0.05). The prevalence rates of malnutrition and mild wasting in each year were higher in boys (13.7%, 7.6%; 7.5%, 5.0%; 7.1%, 4.5%) than in girls (10.3%, 4.4%; 5.5%, 2.7%; 4.8%, 2.5%) ( χ 2=54.45, 88.67; 47.04, 81.07; 85.28, 98.81; P <0.01). The difference in malnutrition prevalence between urban and rural areas gradually narrowed (12.5%, 11.6%; 6.9%, 6.3%; 6.0%, 6.0%), with no statistically significant difference in 2021 ( χ 2= 0.01 , P >0.05). Malnutrition among primary and secondary school students was primarily characterized by mild wasting (56.0%) in Zhejiang Province. Compared to 2008, the prevalence of malnutrition in 2014 and 2021 showed a steady upward trend with increasing age in Zhejiang Province( χ 2 trends =44.52, 11.78, P <0.01). Conclusions The prevalence of malnutrition among primary and secondary school students aged 9 to 17 years in Zhejiang Province decreases by year from 2008 to 2021. However, the prevalence increase steadily with age, and boys have a higher prevalence of malnutrition. Policies should be developed age , gender , and growth appropriate dietary patterns to reduce malnutrition among primary and secondary school students.

Objective: To investigate the prevalence and associated factors of depressive symptoms among middle and high school students in Zhejiang Province, so as to provide scientific basis for the implementation of depressive intervention. Methods: Based on the health status and associated factors of middle and high school students in the project "Monitoring of Common Diseases and Health Influencing Factors of Students" during 2018 to 2021, a total of 73 309 students including middle school, ordinary high school and vocational high school surveyed in 11 cities of Zhejiang Province were selected by multi stage stratified cluster random sampling method. From 2018 to 2021, there were 6 008, 21 917, 23 712 and 21 672 students, respectively. The Chi square test and Logistic regression model were used to analyze the influencing factors of depressive symptoms in middle and high school students. Results: From 2018 to 2021, depressive symptoms detection rate of middle school students was 14.8%, with higher rate in girls (17.1%) than in boys (12.7%), higher rate in high school (17.1% in ordinary high school, 17.6% in vocational high school) than middle school (12.5%)( χ 2=278.77, 327.22, P <0.05). Univariate analysis showed that there were statistically significant differences in depressive symptoms detection rate among middle school students with different years (2018: 16.7%，2019: 17.9% , 2020: 13.1%, 2021: 13.0%), residence (yes: 16.3%, no:13.5%), body mass index classification (not overweight or obesity: 14.8%, overweight: 14.2%, Obesity: 15.7%), weekly exercise days (0-2 d: 17.1%, 3-5 d: 12.5%, 6-7 d: 13.1%) and bullying (yes: 35.5%, no: 10.7%) ( χ 2=293.40, 118.35, 7.83, 287.24, 4 978.84, P <0.05). Multivariate Logistic regression analysis showed that female students, ordinary high schools, vocational high schools, obesity, school bullying were positively correlated with depression ( OR =1.65, 1.70, 1.60, 1.12, 5.21), exercise 3 to 5 days per week, exercise 6 to 7 days per week were negatively correlated with depression ( OR=0.77, 0.81, P <0.01). Conclusions Depressive symptoms among middle and high school students in Zhejiang Province are prominent. Strengthening mental health education for students and providing attention and support from families, schools, and society are essential steps to reduce the occurrence of depressive symptoms among these students.