BackgroundChildhood obesity has been increasing rapidly worldwide. There is limited evidence for effective lifestyle interventions to prevent childhood obesity worldwide, especially in developing countries like China. The objective of this study was to assess the effectiveness of a school-based multi-component lifestyle childhood obesity prevention program (the CLICK-Obesity study) in Mainland China.MethodsA cluster randomized controlled trial was developed among grade 4 students from 8 urban primary schools (638 students in intervention, 544 as control) in Nanjing City, China. Students were randomly allocated to the control or intervention group at school-level. A one-year multi-component intervention program (classroom curriculum, school environment support, family involvement and fun programs/events) together with routine health education was provided to the intervention group, while the control group received routine health education only. The main outcome variables assessed were changes in body mass index, obesity occurrence, obesity-related lifestyle behaviors and knowledge.ResultsOverall, 1108 (93.7%) of the 1182 enrolled students completed the intervention study. The intervention group had a larger marginal reduction than did the control group in overall mean BMI value (-0.32±1.36 vs. -0.29±1.40, p = 0.09), although this was not significant. Compared with the control group, the intervention group was more likely to decrease their BMI (OR = 1.44, 95%CI = 1.10, 1.87) by 0.5 kg/m2 or above, increase the frequency of jogging/running (OR = 1.55, 95%CI = 1.18, 2.02), decrease the frequency of TV/computer use (OR = 1.41, 95%CI = 1.09, 1.84) and of red meat consumption (OR = 1.50, 95%CI = 1.15, 1.95), change commuting mode to/from school from sedentary to active mode (OR = 2.24, 95%CI = 1.47, 3.40), and be aware of the harm of selected obesity risk factors.ConclusionsThe school-based lifestyle intervention program was practical and effective in improving health behaviors and obesity-related knowledge for children in China. This study provides important policy implications on school-based intervention programs for modifications of obesity-related lifestyles.Trial RegistrationChinese Clinical Trial Registry ChiCTR-ERC-11001819

Background: An inverse relationship between physical activity (PA) and depression among adolescents has been reported in developed communities without consideration of sedentary behaviors (SB, including sitting for course study, viewing TV, and sleeping). We explored the association between recreational PA time (hr/wk) and depression after adjustment with SB and other possible confounders among Chinese adolescents.

Background:Childhood obesity has been becoming a worldwide public health problem. We conducted a community-based physical activity (PA) intervention program aiming at childhood obesity prevention in general student population in Nanjing of China, the host city of the 2nd World Summer Youth Olympic Games (YOG-Obesity study).Methods:This was a cluster randomized controlled intervention study. Participants were the 4th (mean age±s.e.: 9.0±0.01) and 7th (mean age±s.e.: 12.0±0.01) grade students (mean age±s.e.: 10.5±0.02) from 48 schools and randomly allocated (1:1) to intervention or control groups at school level. Routine health education was provided to all schools, whereas the intervention schools additionally received an 1-year tailored multi-component PA intervention program, including classroom curricula, school environment support, family involvement and fun programs/events. The primary outcome measures were changes in body mass index, obesity occurrence and PA.Results:Overall, 9858 (97.7%) of the 10091 enrolled students completed the follow-up survey. Compared with the baseline, PA level increased by 33.13 min per week (s.e. 10.86) in the intervention group but decreased by 1.76 min per week (s.e. 11.53) in the control group (P=0.028). After adjustment for potential confounders, compared with the control group, the intervention group were more likely to have increased time of PA (adj. Odds ratio=1.15, 95% confidence interval=1.06–1.25), but had a smaller increase in mean body mass index (BMI) (0.22 (s.e. 0.02) vs 0.46 (0.02), P=0.01) and BMI z-score (0.07 (0.01) vs 0.16 (0.01), P=0.01), and were less likely to be obese (adj. Odds ratio=0.7, 95% confidence interval=0.6, 0.9) at study end. The intervention group had fewer new events of obesity/overweight but a larger proportion of formerly overweight/obese students having normal weight by study end.Conclusions:This large community-based PA intervention was feasible and effective in promoting PA and preventing obesity among the general student population in a large city in China. Experiences from this study are the lessons for China to control the childhood obesity epidemic.

Objective Previous studies in China showed large sex differences in childhood overweight and obesity (ow/ob) rates. However, limited research has examined the cause of these sex differences. This study aimed to examine individual and parental/familial factors associated with sex differences in childhood ow/ob rates in China. Design Variables associated with child weight status, beliefs and behaviors, and obesity-related parenting practices were selected to examine their sex differences and association with a sex difference in child ow/ob outcomes using logistic regression analysis. Setting Cross-sectional data analysis using the 2011 China Health and Nutrition Survey. Subjects Children aged 6–17 years (n=1,544) and their parents. Results Overall child ow/ob prevalence was 16.8%. Adolescent boys (AB; 12–17 years) were about twice as likely to be ow/ob as adolescent girls (AG; 15.5 vs. 8.4%, p<0.05). AB more likely had energy intake exceeding recommendations, self-perceived underweight, underestimated their body weight, and were satisfied with their physical activity level than AG. AG more likely practiced weight loss management through diet and self-perceived overweight than AB. Mothers more likely identified AG’s weight accurately but underestimated AB’s weight. Stronger associations with risk of childhood ow/ob were found in boys than girls in dieting to lose weight (OR= 6.7 in boys vs. 2.6 in girls) and combined maternal and child perception of the child’s overweight (OR= 35.4 in boys vs. 14.2 in girls). Conclusions Large sex differences in childhood obesity may be related to the sex disparities in weight-related beliefs and behaviors among children and their parents in China.

SEP are heterogeneous in the four Chinese megacities, high-income areas. They affect child unhealthy eating and overweight/obesity, and are critical for fighting childhood obesity in China.

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In the context of recent social and economic transitions in China, lack of physical activity among adolescents is an emerging health risk, particularly so in rapidly expanding urban areas. Evidence from Western countries suggests that built environment attributes can influence the physical activity participation of young people, but whether or not this is the case for China is unknown. We recruited high school students from ten urban districts in Nanjing, Mainland China (n=2,375; mean age=13.9± 1.0 years old; 46% boys; survey response rate=89%). The outcome variable was selfreported recreational physical activity time; the primary explanatory variable was the residential density of the urban districts. Analysis was conducted using mixed-effects logistic regression models. After adjustment for potential confounding variables, including sedentary behavior and green space, there was a consistent and graduated association between residential density and physical activity; residential density was significantly negatively associated with recreational physical activity time for students from the higher tertile of residential density (OR; 95% CI=0.64; 0.42 to 0.97) compared to those from the lower tertile. The direction and magnitude of the negative association between residential density and physical activity was similar for boys and girls. It should be a public health priority to identify the particular urban environment attributes that can encourage and support young people's participation in physical activity.

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