Backgrounds: Many literature reviews summarized relationships between screen time and child health, but they only included a few studies conducted in Chinese children and adolescents. The potential influence of screen time may vary by social context. The current systematic review and meta-analysis aimed to evaluate relationships between screen time and health issues among Chinese school-aged children and adolescents. Methods: Peer-reviewed articles written in Chinese and English were retrieved from CNKI, Wanfang, PubMed, Embase, and Web of Science from inception to June 2020. The Downs & Black checklist was applied to assess study quality. Meta analyses used random effect models and mixed effects model to calculate pooled adjusted odds ratios and 95% confidence intervals. Heterogeneity, sensitivity, and publication bias were assessed using Q and I² statistics, “one-study removed” analysis, the funnel plot, trim and fill analysis, and classical fail-safe N, respectively. Results: In total, we identified 252 articles reporting 268 studies with unique samples. These studies investigated relationships between screen time and health issues of adiposity, myopia, psycho-behavioral problems, poor academic performance, cardiometabolic disease risks, sleep disorder, poor physical fitness, musculoskeletal injury, sub-health, and miscellaneous issues of height and pubertal growth, injury, sick leave, and respiratory symptoms. Proportions of studies reporting positive relationships with screen time were lowest in adiposity (50.6%) and higher in myopia (59.2%) and psycho-behavioral problems (81.8%). Other health issues were examined in 10 or less studies, all of which had more than half showing positive relationships. The pooled odds ratio from 19 studies comparing health risks with the screen time cutoff of 2 hours per day was 1.40 (95% CI: 1.31 to 1.50, I² = 85.9%). The pooled effect size was 1.29 (95% CI: 1.20 to 1.39) after trimming 7 studies for publication bias adjustments. Conclusions: Findings exclusively generated from Chinese school-aged children and adolescents resonate those mainly from western countries. Evidence suggests that higher levels of screen time are related with greater risks of various health issues, although the relationships appear to be weak and intertwined with other confounding factors. Future studies need to investigate health-specific dose effects and mechanisms of screen time.

Background: Whether and to what extent outdoor activity and screen time are relevant to adiposity among rural adolescents remain largely unknown as most of relevant evidence was generated from high-income countries and urban areas. This study aimed to investigate associations of outdoor activity and screen time with adiposity among early adolescents living in rural southwest China. Methods: In this cross-sectional study, seventh graders (n = 2264) were recruited from 10 middle schools of a rural county. Overweight and obesity was assessed using adolescents’ body mass index and waist circumference. Adolescents’ outdoor activity and screen time were measured using self-reported daily time spending on outdoor activity, watching TV, playing video games, and computers on weekdays and weekends, respectively. Results: The prevalence of overweight/obesity and high waist circumferences were 8.0 and 4.9% and were higher among those from one-child families and with parents having high school or higher education and whose fathers were not farmers. Adolescents who did not have ≥1 h outdoor activity on weekdays were more likely to be overweight/obese (OR: 1.86, 95% CI: 1.30, 2.66) and have high waist circumferences (OR: 2.22, 95%CI: 1.39, 3.57). Adolescents who had > 2 h screen time on weekends were more likely to have high waist circumferences (OR: 2.08, 95% CI: 1.14, 3.80). Lack of outdoor activity and excessive screen time also showed synergistic effects on overweight/obesity (OR: 1.93. 95% CI: 1.15, 3.24) and high waist circumferences (OR: 3.02, 95% CI: 1.54, 5.94). Conclusions: Lack of outdoor activity and excessive screen time were relevant to adiposity among rural Chinese adolescents even when the obesity prevalence was low. Efforts to promote active lifestyles may help prevent rural adolescents from losing their advantage in the era of the global obesity epidemic.

Parental perception of children’s weight may influence parents’ feeding practices, and in turn, child dietary intake and weight status; however, there is limited evidence generated for preschoolers. The aim of this cross-sectional study was to investigate associations between Chinese parents’ perceptions of child weight, feeding practices and preschoolers’ dietary patterns. Participants (1616 parent-child pairs) were recruited from six kindergartens in Hunan, China. Parents’ misperception, concern, and dissatisfaction on child weight were collected through a self-administered caregiver questionnaire. Parental feeding practices and children’s dietary intake were, respectively, assessed using the Child Feeding Questionnaire and a Food Frequency Questionnaire. Linear regression models were applied to analyze associations between parental weight perceptions, feeding practices, and preschooler’s dietary patterns. Associations between parents’ weight perceptions and dietary patterns were significant only among underweight children. Regardless of child weight status, parental weight underestimation and preference for a heavier child were positively associated with pressure-to-eat. Parental weight concern was positively associated with restriction in normal weight child, but this was not found in other weight groups. In conclusion, Parents’ misperception, concern, and dissatisfaction about child weight are associated with parents’ feeding practices and may influence preschoolers’ dietary quality, but the relationships vary by children’s actual weight status.

Latino adolescents face challenges to performing energy balance–related behaviors (EBRBs) to prevent childhood obesity, including healthy dietary intake, adequate physical activity, and limited screen time. Fathers are underrepresented in family-based obesity interventions but could be influential in shaping the EBRBs of Latino children. Three types of parenting practices (setting expectations/limits, role modeling, managing availability and accessibility) have shown relatively consistent positive relationships with children’s EBRBs in studies that have mostly involved mothers. The purpose of this study was to develop measures to assess Latino fathers’ parenting practices based on existing measurement instruments, focus groups and cognitive testing. Criterion validity of the measures (40 items) was examined with Latino fathers and their early adolescents (10-14 years old, n = 96 dyads) who were predominantly from low-income, two-parent households. Criterion validity was indicated by significantly higher intakes of fruit and vegetables; lower intakes of sugar-sweetened beverages, sweets/salty snacks and fast foods; more weekly physical activity hours; and fewer daily screen time hours among adolescents who reported high versus low levels/frequencies of supportive parenting practices. In addition, nearly all scales of adolescent-reported paternal behavioral modeling and availability/accessibility practices were significantly correlated with adolescents’ corresponding EBRBs (r = 0.22 to 0.54). However, poor validity and agreement with early adolescents’ reports were found for most father-reported parenting practices. Overall, this study indicated that the measures were acceptable for assessing adolescents’ report of Latino fathers’ parenting practices around EBRBs. The findings also indicate the importance of including early adolescents’ reports in measuring paternal parenting practices.