Abstract With the socio economic development and urbanization, obesity increased dramatically worldwide among children and adolescents over the past years. The determinants of obesity are complicated, and its association with built environment in community has received great concern in recent years. To provide theoretical basis for building supportive environment beneficial for obesity prevention, the review summarizes obesity related built environment, including food environment, physical activity environment, road traffic environment, lighting at night.

Objective: To describe the prevalence and association of dietary rhythm and depressive symptoms among adolescents, so as to provide a basis for improving unhealthy behavioral habits,and to promote adolescent physical and mental health. Methods: From October to December 2021, a total of 22 868 students were selected from one middle school and high school in urban and rural areas of eight cities, namely, Shenyang, Xuzhou, Shenzhen, Taiyuan, Nanchang, Zhengzhou, Chongqing, and Kunming cities, China, using a combination of purposive sampling and stratified cluster random sampling. A self administered questionnaire was used to assess adolescents dietary rhythm, and the Patient Health Questionnaire-9 (PHQ-9) was used to assess depressive symptoms. Binary Logistic regression model was employed to analyze the associations between adolescent dietary rhythm and depressive symptoms, while the associations between adolescent dietary rhythm and depressive symptoms across gender and physical activity levels were stratified by gender and physical activity levels. Results: The detection rate of depressive symptoms in adolescents was 44.4%. The respective differences in the detection rates of depressive symptoms among adolescents of different genders, physical activity levels, and dietary rhythm disorders were statistically significant ( χ 2=157.51, 105.02, 3 282.50, P <0.01). Taking the low disordered dietary rhythm group as the reference, binary Logistic regression analyses showed that after adjusting for confounding factors such as age, gender，family location, family economic situation, whether only child, parental education level, and learning burden, physical activity levels, depressive symptoms were positively correlated with adolescents in the moderate disordered dietary rhythm group ( OR=2.63, 95%CI =2.45-2.83) and the high disordered dietary rhythm group ( OR=6.38, 95%CI = 5.93- 6.86). In addition, after stratifying by gender, dietary rhythm were positively correlated with depressive symptoms. The moderate disordered group (male: OR=2.62, 95%CI =2.37-2.89, female: OR=2.67, 95%CI =2.40-2.97) and the highly disordered group (male: OR=5.74, 95%CI =5.19-6.35, female: OR=7.11, 95%CI =6.40-7.89) were positively correlated with depressive symptoms. After stratification by physical activity levels, low, moderate and above physical activity levels among adolescents in the disordered dietary rhythm group (low physical activity: OR=2.91, 95%CI =2.58-3.29, moderate and above physical activity: OR= 2.50, 95%CI =2.28-2.74), high disordered group (low physical activity: OR=6.51, 95%CI =5.94- 7.13 , moderate and higher physical activity: OR=6.18, 95%CI =5.47-6.97) were positively associated with depressive symptoms ( P <0.01). There was an interaction between dietary rhythm and physical activity levels in regard to the development of depressive symptoms in adolescents, taking the group with moderate and above physical activity levels and low disordered dietary rhythm as the reference,the detection rate of which was higher in adolescents with low levels of physical activity and those in the moderate or high disordered dietary rhythm group ( OR=1.50, 3.90, 95%CI=1.39-1.61, 3.63-4.19, P <0.01). Conclusions Dietary rhythm disorders were found to be positively associated with depressive symptoms in adolescents. Regular dietary behaviors and increased physical activity play an important positive role in promoting adolescent mental health.

Objective: To develop a simplified Rating Questionnaire of Social Ecological Risks in Adolescents and to evaluate the reliability and predictive validity of the brief questionnaire, so as to provide data and evidence support for building the evaluation system of cumulative social ecological risk exposure. Methods: A large cross sectional was conducted in eight areas, including Shenzhen, Zhengzhou, Xuzhou, Nanchang, Shenyang, Taiyuan, Kunming and Chongqing, from October to December 2021. A total of 22 868 adolescents were included in the analysis. Data on healthy behaviors from 10 838 adolescents from Shenyang, Taiyuan, Kunming, Chongqing were used for item selection, based on factor analysis, validity and reliability evaluation. The data from Shenzhen, Zhengzhou, Xuzhou, Nanchang, including 12 030 adolescents, were used to define the partition values of the brief questionnaire, and evaluate the predictive validity. Results: The brief questionnaire containing 25-item were developed by analyzing and choosing all items of original questionnaire, and covered seven dimensions including individual, family, school, community, policy, time and culture. The cumulative contribution rate of variance was 54.95%, the Cronbach coefficient was 0.79, and the split half coefficient was 0.70. Participants in the higher risk group had significantly higher risk of smoking ( OR =4.05, 95% CI = 2.78 -5.92), drinking ( OR =3.47, 95% CI =2.86-4.19), suicidal ideation ( OR =8.85, 95% CI =7.68-10.21), suicidal plans ( OR = 8.85, 95% CI =7.27-10.78), suicidal attempt ( OR = 8.86 , 95% CI =6.67-11.78) than individual in the lower risk group ( P < 0.05). After stratified by gender, the above positive correlations still remained significant( P <0.05). Conclusion The brief questionnaire, with good reliability and predictive validity, could be widely applicated in the further researches on social ecological risk factors.