Objective: To evaluate the effectiveness of a comprehensive intervention for childhood obesity on self-efficacy, weight perception, and stage of behavior change, and to provide a scientific evidence for childhood obesity interventions. Methods: The study was a cluster randomized controlled trial. Twelve primary schools and 1 889 children (aged 7-11 years) from Dongcheng District in Beijing were recruited in September, 2013, and were administered a comprehensive intervention for childhood obesity. Six schools (930) were randomly allocated to the intervention group, and six schools (959) were randomly allocated to the control group. A face-to-face questionnaire survey was carried out, R 4.0.3 software was used to analyze the data, and multiple linear regression model was used to analyze the intervention effect. Results: After the intervention, mean (standard deviation) scores of self-efficacy among children in the intervention and control groups were (4.4±0.9) and (4.2±1.1), respectively. After the intervention, the proportion of children in the intervention group who underestimated or overestimated their body weight was 28.4% and 11.3 %, respectively, while the figures in the control were 37.1% and 6.9%; compared with the control, the risk of underestimating body weight decreased among children in the intervention group( OR=0.64, 95%CI=0.52-0.80, P <0.01), while the risk of weight overestimation increased( OR=1.79, 95%CI=1.26-2.54, P <0.01). After the intervention, the proportion of children in the contemplation or action stage of behaviour change was 65.3% and 83.6%, while the figures in the control group were 59.8% and 69.8 %, respectively; in comparison with the control group, more children in the intervention group were in comtemplation ( OR= 1.28 , 95%CI=1.03-1.59, P =0.02) or action stage of behaviour change( OR=2.59, 95%CI=2.04-3.27, P <0.01). Conclusion The comprehensive intervention for childhood obesity improved self-efficacy, weight perception, and facilitated behavior change, but may increase the risk of weight overestimation.

Objective: To evaluate the effect of a dietary and exercise intervention on cognition and behaviors among primary school students, and to further explore the mediating role of family support, in order to provide scientific evidence for future effective intervention strategies. Methods: A dietary and exercise intervention program for childhood obesity prevention was carried out in 24 primary schools in Beijing, Changzhi and Urumqi from 2018 to 2019, and 1 392 children in grade four as well as their parents were included. Family support and children s cognition and behaviors were collected through questionnaire. To carry out diet and exercise behavior intervention on the three levels of school, family and individual in the intervention group,and children s dietary and exercise knowledge, eating habits, physical activities, as well as sedentary and screen behaviors were evaluated. The linear mixed model was used to analyze the effect of intervention on children s cognition and behaviors, and the mediation model was used to explore the role of family support. Results: The proportion of children with higher score of dietary and exercise knowledge ( OR= 2.34 , 95%CI =1.71-3.21), eating habits ( OR=2.58, 95%CI =1.75-3.82), and sedentary and screen behaviors ( OR=1.91, 95%CI =1.35-2.68) increased in the intervention group after one year intervention ( P <0.01), compared with the control group, respectively. The intervention also increased the proportion of children s family support in the intervention group compared with the control group ( OR=3.45, 95%CI =2.19-5.45), and the support from children s fathers ( OR=2.70, 95%CI =1.68-4.35), mothers ( OR=3.71, 95%CI =2.28-6.04), paternal grandmothers ( OR=1.65, 95%CI =1.00-2.70), and maternal grandmothers ( OR= 2.14, 95%CI =2.12-2.16) increased significantly ( P <0.05). The mediation analysis showed that family support played a mediating role in association between comprehensive intervention and children s eating habits as well as sedentary and screen behaviors. Conclusion The dietary and exercise intervention effectively promoted children s cognition and behaviors, and family support played an important mediating role.

Objective: To evaluate the cost effectiveness of a school based comprehensive intervention for childhood obesity and to provide scientific basis for formulating and promoting efficient and economic intervention measures for childhood obesity. Methods: In a cluster randomized controlled trial, 12 primary schools (1 889 students from grade 3 to 5) in Dongcheng District in Beijing were selected and randomly assigned to the intervention (6 schools, 930 students) and control group (6 schools, 959 students). Students in the intervention group received a one year school based comprehensive intervention for childhood obesity, including development of school level policies, health education activities, improvement of physical activity, and improvement of healthy diet. A cost analysis method from a social perspective was used to evaluate the implementation costs of the intervention. Cost effectiveness analysis was used by calculating incremental cost effectiveness ratio (ICER) on obesity related knowledge, number of days completing no less than 60 minutes of moderate to vigorous physical activity (MVPA) per week, students consuming sugar sweetened beverage. Results: The material cost and human cost were 46 376.24 yuan and 46 197.32 yuan, respectively. The total cost of the intervention was 92 573.56 yuan and the average cost was 99.54 yuan per student in the intervention group. ICER on obesity related knowledge, number of days completing no less than 60 minutes of MVPA per week, percentage of students consuming sugar sweetened beverage were 52.39%, 71.61% and 2.26%, respectively. Conclusion The school based comprehensive intervention for childhood obesity shows a good cost effectiveness promoting students obesity related knowledge, as well as dietary and physical activity behaviors.

Objective: To explore the mediation effect of eating behavior in the personality obesity association, so as to provide scientific evidence for preventing childhood obesity in China. Methods: This study investigated 1 271 children in September 2018 among Beijing, Changzhi and Urumuqi. By used NEO five Factor Inventory to assess characteristics of personality and used Children Eating Behavior Questionnaire to measure eating behaviors in children. Five obesity related indicators [body mass index (BMI), BMI Z score, waist circumference, waist to hip ratio and body fat percentage] were derived from physical examination. Results: After adjusting for sex, age and region, the standardization scores of conscientiousness were negatively associated with BMI( B= -0.227 , 95%CI =-0.422--0.031), BMI Z score( B=-0.081, 95%CI =-0.158--0.006), waist circumference( B=-0.720, 95%CI = -1.281--0.159), waist to hip ratio( B=-0.004, 95%CI =-0.007--0.001) and body fat percentage ( B=-0.727, 95%CI = -1.293--0.162)( P <0.05). Results from the mediation analysis showed that the associations between conscientiousness and BMI, BMI Z score, waist circumference, waist to hip ratio and body fat percentage were partly mediated through food responsiveness and emotional eating behaviors; with effects ranged from 27.5%-47.1% and 0.9%-18.0%( P <0.05). Conclusion Conscientiousness is associated with lower risk of childhood obesity and food responsiveness and emotional eating behaviors show mediating effect in the association between childhood personality and obesity. Health education should be carried out in time for children with low conscientiousness in order to prevent the occurrence of obesity in the early stage.

Objective: To analyze the effect of a comprehensive intervention on the accuracy of children s body size perception, so as to provide a theoretical basis for child body size perception improvement. Methods: The participants were selected from a cluster randomized controlled trial (September 2018 to June 2019). A total of 1 287 children in 24 primary schools (clusters) equally distributed among three regions (Beijing, Changzhi and Urumqi) were selected, which included 12 intervention schools (648 students) and 12 control schools (639 students). The accuracy of body size perception was measured by Ma figural stimuli. A linear mixed model was employed to analyze the effect of the comprehensive intervention on the accuracy of children s body size perception. Results: At baseline, the accuracy rate of body size perception among children in the intervention group and the control group was 56.6% and 51.5%, respectively. The underestimation rate was 42.0% and 47.7%, and the overestimation rate was 1.4% and 0.8%. After the intervention, compared with the control group, the inaccuracy rate ( OR=0.50, 95%CI=0.37-0.68, P <0.01) and the underestimation rate in the intervention group decreased ( OR=0.37, 95%CI=0.26-0.54, P <0.01). There was no significant difference in the overestimation rate between the two groups( P =0.51). The results of the stratified analysis showed that the intervention could improve the accuracy of children s body size perception, regardless of their gender, nutritional status, region, or whether or not they were only child( P >0.05). Conclusion The inaccuracy rate of children s body size perception, which mainly involved underestimation was high. A comprehensive intervention can effectively reduce body size underestimation and improve the accuracy of children s body size perception.

Objective: This study aims to explore the influencing factors of influenza vaccination in middle school students, and to provide a theoretical basis for improving the influenza vaccination rate and inform interventions. Methods: By using mixed research method, a combination of qualitative research and quantitative research, a survey was conducted among 9 145 middle school students selected from Beijing, Anhui, Shaanxi, Guangdong via the online survey using Wenjuanxing software. Multivariate Logistic regression models were used to analyze the influencing factors of influenza vaccination. After a purposeful sampling, 35 middle school students were invited for semi structured interviews and NVivo plus software were used for data analysis. Results: The self reported influenza vaccination rate of the middle school students was 38.2%. No experience of discussing an influenza vaccine with others ( OR=1.37, 95%CI =1.17-1.60) and devaluing the discussion about vaccination ( OR=1.30, 95%CI =1.08-1.57) was negatively associated with vaccination( P <0.05); The head teacher suggestion(OR=0.39, 95%CI =0.32-0.48), peers vaccination( OR= 0.29, 95%CI =0.25-0.33), and awareness of what the vaccine was and being able to explain it clearly( OR=0.68, 95%CI =0.61-0.75), discussing with others( OR=0.76, 95%CI =0.67-0.86), feeling the discussion is valuable( OR=0.66, 95%CI = 0.59- 0.73), being able to positively influence others( OR=0.61, 95%CI =0.55-0.68), being positively influenced by others ( OR= 0.62, 95%CI =0.54-0.71) were more likely to take vaccination via separated models( P <0.05). The interview results showed that the teacher s cognition and attitude towards the influenza vaccine could directly or indirectly affect the students vaccination decision, and the positive school opinion atmosphere may improve students vaccination rate. Conclusion It is suggested that the schools should increase students vaccination rate through head teachers guidance and organizing students to participate in discussion on influenza topics.

Objective:To investigate the relationships between hyperuricemia and the incidence risk for cardiometabolic abnormity in children.Methods:Data were obtained from School-based Cardiovascular and Bone Health Promotion Program. In 2017, a total of 15 391 children aged 6-16 years in Beijing were selected through stratified cluster sampling at baseline survey. Follow-up investigation was conducted in 2019. Logistic regression model was used to analyze the relationships of uric acid quartiles and change in uric acid levels with incidence risks for cardiometabolic abnormity (hypertension, hyperglycemia and dyslipidemia).Results:A total of 8 807 children (4 376 boys, 4 431 girls) were included in the analysis, the average age of the children was (11.1±3.3) years at baseline survey. The adjusted odds ratios ( ORs) and 95% confidence intervals ( CIs) of incidence risk for hypertension in the third and fourth quartiles of the UA were 1.39 (1.11-1.75) and 1.56 (1.19-1.81), respectively. The ORs and 95% CIs of risk for high LDL-C in the second, third and fourth quartiles were 1.88 (1.16-3.05),1.98 (1.23-3.17) and 2.25 (1.42-3.57). The uric acid level increased by one standard deviation, the risk increased by 17% for hypertension and 27% for high LDL-C. The uric acid level increased by 10 μmol/L, the risk increased by 2.1% for hypertension and 2.9% for high LDL-C. The gender-stratified analysis showed that the similar results. The ORs and 95% CIs were 1.32 (1.09-1.60) and 1.50 (1.05-2.16) for hypertension, 1.90 (1.38-2.60) and 2.96 (1.58-5.52) for high TC, 1.78 (1.26-2.51) and 2.84 (1.60-5.03) for high LDL-C in the groups of newly diagnosed hyperuricemia and persistent hyperuricemia. Conclusions:Higher uric acid level was associated with increased incidence risks for hypertension, abnormal TC and LDL-C. Maintaining optimal uric acid level by children might contribute to the early prevention of cardiovascular diseases.

Objective:To analyze the influence of obesity status on the development of cardiometabolic disorders in school-age children.Methods:Information about children's body weight, body height and cardiovascular risk factors were collected in baseline survey in 2017 and follow-up survey in 2019. The school-age children were divided into four groups based on their baseline and follow-up obesity status, i.e. sustained non-obesity group, restored obesity group, newly classified obesity group, and persistent obesity group. Analysis of covariance was used to compare the difference of change in levels of cardiometabolic factors among the four groups. The multivariate logistic regression model was used to analyze the relationship between obesity status and the incidence risk of cardiometabolic disorders.Results:The present study included 11 379 school-age children (boys accounting for 49.6%). During the 2 years, the incidence of obesity was 3.2% (95% CI: 2.9%-3.5%) with the restoration ratio of obesity of 4.4% (95% CI: 4.0%-4.8%). Compared with the sustained non-obesity group, increases in SBP, DBP, TG, LDL-C and non-HDL-C were much higher in newly classified obesity group and persistent obesity group, but lower in restored obesity groups except for DBP (all P<0.05). In addition, the incidence risk of hypertension, high glucose, dyslipidemia and cardiometabolic disorders (≥2 risks) were much higher in newly classified and persistent obese children than in sustained non-obese children. No difference was found in incidence risks of most cardiovascular disorders between restored obese children and sustained non-obese children, except for hypertension and cardiometabolic risks. Conclusion:Both newly classified obesity and persistent obesity increased the incidence risks for multi cardiovascular disorders, while these risks could be reduced when non-obese status restore.

Objective:To investigate the incidence and risk factors of pediatric fracture in school-age children and adolescents in Beijing.Methods:A total of 12 056 students with complete fracture data of 2017 baseline survey and 2019 follow-up survey of School-based Cardiovascular and Bone Health (SCVBH) Promotion Program in Beijing were selected as study subjects. Logistic regression model was used to analyze associations of fracture incidence with age, BMI, fracture history and lifestyle.Results:The 2-year accumulative incidence rate of pediatric fracture was 3.1% (95% CI: 2.8%-3.4%) in school-age children and adolescents in Beijing, which was much higher in boys (4.1%) than in girls (2.1%) and increased with age in boys but decreased with age in girls. Fractures mainly occurred at upper-limb (69.0%), no gender and age specific significant in fracture sites were observed. Fracture history was the risk factor for fracture incidence in both boys and girls (boys: RR=1.81, 95% CI: 1.18-2.64; girls: RR=3.11, 95% CI: 1.74-5.13). In addition, higher duration and frequency of moderate to vigorous physical activities (≥120 min/day) and frequent consumption of sugar sweetened beverage (≥1 time/week) were also found to increase fracture risk in boys. Conclusion:The incidence of pediatric fracture was associated with gender, age, fracture history and lifestyle habits in school-age children and adolescents in Beijing. Targeted strategies are needed to prevent childhood fracture.

Objective:To investigate the association between vitamin D nutritional status and the body muscle mass in children.Methods:Data were obtained from School-based Cardiovascular and Bone Health Promotion Program. In 2017, a total of 15 391 children aged 6-16 years in Beijing were selected through stratified cluster sampling in baseline survey. A follow-up investigation was conducted in 2019. The questionnaire survey and the detection of serum 25-hydroxyvitamin D [25(OH)D] level were conducted. The bioelectrical impedance analysis (BIA) apparatus was used to measure body muscle mass, and muscle mass index (MMI) was calculated. Multivariable linear models were used to analyze the association of vitamin D nutritional status with the baseline and follow-up MMI measures.Results:A total of 10 890 children aged (11.5±3.3) years(boys accounting for 49.6%) were included in the analysis. The average 25(OH)D level was (35.4±12.0) nmol/L, with an adequacy ratio of 11.1%. After multivariate linear regression adjustment for age, sex, body fat mass, smoking status, alcohol use status, dairy supplement, calcium supplement, physical activity, and pubertal development, no statistically significant association between vitamin D nutritional status and baseline MMI level was observed ( P>0.05). For the follow-up MMI, the Z-score increased by 0.008 ( P=0.058) for per 10 nmol/L increase in 25(OH)D, which were 0.002 ( P=0.815) and 0.037 ( P=0.031) higher in children with insufficient and adequate vitamin D than those with vitamin D deficiency, respectively ( P for trend =0.089). Subgroup analysis showed that in the normal BMI group, for per 10 nmol/L increase in 25 (OH) D, the MMI at baseline survey and MMI Z-score at follow-up of children with adequate vitamin D and increased by 0.019 and 0.014, respectively (both P<0.05). Conclusions:Vitamin D nutritional status was related to muscle mass in children, and children with adequate vitamin D tended to obtain higher MMI. Children and adolescents are encouraged to maintain sufficient vitamin D levels, strengthen nutrition and exercise to promote body health.