Trends of physical activity and recreational screen time among Chinese children and adolescents: a national study from 2017 to 2019.

BACKGROUND: The prevalence of physical inactivity and sedentary behavior among children and adolescents is a growing public health concern. This study aims to examine the trends in Physical Activity (PA) and Recreational Screen Time (RST) amongst children and adolescents in China, considering variations in genders, school levels, areas (urban versus rural), and regions (north versus south). The findings provide a foundation to guide policy and strategy making for future health promotion and development. METHODS: An annual national cross-sectional survey was conducted in China from 2017 to 2019 cumulatively involving 52,503 (48% female) children and adolescents from grades 4 to 12 (aged 12.72 ± 2.12). Data on PA and RST were collected through self-administered questionnaires. Weighted least squares regression was used to analyze the trends and differences in PA and RST among the participants' profiles. RESULTS: There was an annual decreased in PA compliance rate of approximately 3.43% (95% CI: 0.79-6.08%) for primary school students, primarily among males residing in rural areas, and in northern regions. Middle school students experienced a yearly decrease of about 5.23% (95% CI: 2.55-7.92%) in PA compliance across all genders, regions, and urban areas. Similarly, the RST compliance rates for primary school students declined by approximately 3.18% (95% CI: 1.57-4.78%) annually for all genders and areas, but only in the northern regions. CONCLUSIONS: This research highlights a downward trend in PA and RST compliance amongst Chinese children and adolescents, with variations based on school level, gender, area, and region. Urgent policies and interventions are imperative to promote PA while mitigating excessive RST within these populations.

The effects of COVID-19 on the Physical Activity and Recreational Screen Time among Chinese children and adolescents.

Background: The lack of Physical Activity (PA) and prolonged Recreational Screen Time (RST) among children and adolescents has been exacerbated during the COVID-19 pandemic, causing this issue to escalate into a crucial public health concern. This study aims to investigate the trends in PA and RST among Chinese children and adolescents from 2019 to 2022, thereby analyzing the short-term and long-term effects of the pandemic on PA and RST among Chinese children and adolescents. Methods: A nationally representative sample of Chinese primary, middle, and high school students was surveyed annually between September and December from 2019 to 2022 using a consistent set of questionnaires. Trends in PA and RST across different school levels, genders, areas (urban/rural), and regions (north/south) were analyzed using Segmented Linear Regression. Results: From 2019 to 2022, the PA and RST of children and adolescents displayed an inverted U-shaped trend, initially increasing and subsequently declining. Specifically, from 2019 to 2021, the PA of children and adolescents significantly increased but dramatically declined from 2021 to 2022. This trend in PA is more pronounced among primary, male, urban, and northern children and adolescent. The RST of children and adolescents increased from 2019 to 2020 but significantly decreased from 2020 to 2022. This trend in RST is more pronounced among primary, urban, and southern children and adolescent. Conclusions: This research unveils the effects of the pandemic on PA and RST in children and adolescents, suggesting short-term beneficial and long-term adverse effects on PA and short-term adverse and long-term beneficial effects on RST. These findings provide a foundation for formulating policies related to children and adolescents' PA and RST during the pandemic.

[Relationship between dietary risk factors and sedentary recreational screen time among school-age children in grades 4-6 in Baise City from 2018 to 2019].

OBJECTIVE: To explore the relationship between dietary risk factors and sedentary recreational screen time of adolescents. METHODS: A total of 6363 pupils of Grades 4-6 from 6 primary schools in Baise were recruited with cluster-sampling method from Sep.2018 to Nov.2019. Participants were asked to report the average duration of watching television, digital devices use, intakes of sugar-sweetened beverage(SSB), snacks, fast-food, soymilk/milk product, skipping breakfast, and frequency of fruit/vegetable. We performed multivariable logistic regression to estimate OR and 95%CI for the relations between duration of sedentary recreational screen time and dietary risk factors, accounting for complex survey sampling and adjusting for potential confounders. RESULTS: (1)Both prolonged watching television and leisure-time digital devices use were associated with high intakes of SSBs, snacks, and low intakes of fruits and vegetables. And compared with <2 h/d, two kinds of screen-time(>4 h/d) was associated with significantly higher odds for intakes of fast food(watching television: OR=2.551;leisure-time digital devices use: OR=3.024), and frequent breakfast skipping(watching television: OR=1.646;leisure-time digital devices use: OR=1.674). (2)Compared with the reference groups(<2 h/d), participants spending more time per day on sedentary recreational screen time were more likely to drink sugar-sweetened beverages(OR=1.717-3.272), consume snacks(OR=1.626-3.154)and less likely to consume fruit/vegetable(OR=1.526-2.251). Compared to ≤2 h/d, estimated ORs of high intakes of fast food were 2.118 for>3 h/d of screen time, and 2.357 for >4 h/d. CONCLUSION: Increased television viewing and digital devices use in adolescence of Grades 4-6 is associated with higher odds of consumption of sweetened beverages, snacks and lower odds of fruit consumption in Baise.

Bidirectional associations of sleep and discretionary screen time in adults: Longitudinal analysis of the UK biobank.

The direction of the association between discretionary screen time (DST) and sleep in the adult population is largely unknown. We examined the bidirectional associations of DST and sleep patterns in a longitudinal sample of adults in the general population. A total of 31,361 UK Biobank study participants (52% female, 56.1 ± 7.5 years) had two repeated measurements of discretionary screen time (TV viewing and leisure-time computer use) and self-reported sleep patterns (five sleep health characteristics) between 2012 and 2018 (follow-up period of 6.9 ± 2.2 years). We categorised daily DST into three groups (low, <3 h/day; medium, 3-4 h/day; and high, >4 h/day), and calculated a sleep pattern composite score comprising morning chronotype, adequate sleep duration (7-8 h/day), never or rare insomnia, never or rare snoring, and infrequent daytime sleepiness. The overall sleep pattern was categorised into three groups (healthy: ≥ 4; intermediate: 2-3; and poor: ≤ 1 healthy sleep characteristic). Multiple logistic regression analyses were applied to assess associations between DST and sleep with adjustments for potential confounders. Participants with either an intermediate (OR: 1.40; 95% CI: 1.15, 1.71) or a poor (OR: 1.16; 95% CI: 1.10, 1.24) sleep pattern at baseline showed higher odds for high DST at follow-up, compared with those with a healthy baseline sleep pattern. Participants with medium (OR: 1.40; 95% CI: 1.14, 1.71) or high DST (OR: 1.62; 95% CI: 1.30, 2.00) at baseline showed higher odds for poor sleep at follow-up, compared with participants with a low DST. In conclusion, our findings provide consistent evidence that a high DST at baseline is associated with poor sleep over a nearly 7 year follow-up period, and vice versa.

Prospective associations between adherence to 24-hour movement guidelines and mental well-being in Chinese adolescents.

Most evidence regarding the relationships between adherence to 24-hour movement guidelines and adolescent mental health have been derived from cross-sectional studies or have ignored positive mental health indicators. The current prospective study examined the associations between adherence to 24-hour movement guidelines and changes in mental well-being among Chinese adolescents over three months. 816 Chinese adolescents (Mage = 14.76 years; SD = 0.81) completed baseline and follow-up scales of 24-hour movement behaviours, mental well-being, and covariates. Linear mixed-effects models were used for data analyses, with adjustments for covariates and mental well-being at baseline. There was a significant improvement in mental well-being across the three months, and the improvement in mental well-being was positively associated with meeting any single guidelines and both physical activity and sleep guidelines but not adherence to all three guidelines. Meeting both physical activity and sleep recommendations appears to exert more significant benefits on mental well-being than meeting one or two other recommendations. An integrative approach to mental health promotion by focusing on 24-hour movement behaviours (at least physical activity and sleep) may be more effective than focusing on a single behaviour alone.

Effectiveness and moderators of a multicomponent school-based intervention on screen time devices: the Movimente cluster-randomized controlled trial.

BACKGROUND: Interventions targeting reduce screen time in adolescents are urgently needed, mainly in low and middle-income countries because of the lack of evidence. Thus, the aims of the study were to examine the effect of a cluster-randomized controlled trial on screen time (ST) devices among Brazilian adolescents and to identify possible moderators. METHODS: Movimente was a multicomponent school-based intervention that was performed in 2017 and consisted of teacher training, education curriculum, and environmental improvements. Baseline and post-intervention assessments (over one academic year) were conducted with students aged 10-16 years at baseline (baseline n = 921, [n = 538 intervention group; n = 383 control group]). A self-report questionnaire was used to measure daily minutes of device specific screen time (TV, computer, video games and smartphone) and demographic variables. Linear mixed models were used to examine intervention effects and an exploratory moderation analysis (sex, grade and socioeconomic status) was performed. RESULTS: The intervention had no significant effects on TV time (ß = - 6.4, 95% CI: - 6.1;13.4), game time (ß = - 8.2, 95% CI: - 7.2;10.8), computer time (ß = 1.1, 95% CI: - 6.3;18.5), smartphone time (ß = - 10.2, 95% CI: - 32.5;12.1), screen time (ß = - 12.8, 95% CI: - 50.5;24.8), meeting screen time guidelines (OR: 1.29, 95% CI: 0.65,2.57) and meeting screen time guidelines with smartphone (OR: 1.66, 95% CI: 0.37,7.40). There was a significant intervention effect on reducing TV time (ß = - 37.1, 95% CI: - 73.0, - 1.3) among 8th grade students only. CONCLUSIONS: The Movimente intervention was effective only for TV time among 8th grade students. Understanding how school-based interventions can improve adolescents' device specific screen time across age groups is needed. Future strategies should cover all screen-based devices. Further, there is a need for more studies in low- and-middle income countries to assist in the development of effective strategies. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT02944318 (25/10/2016).

Combinations of physical activity, sedentary time, and sleep duration and their associations with depressive symptoms and other mental health problems in children and adolescents: a systematic review.

BACKGROUND: For optimal health benefits, the Canadian 24-Hour Movement Guidelines for Children and Youth (aged 5-17 years) recommend an achievement of high levels of physical activity (≥60 min of moderate-to-vigorous physical activity), low levels of sedentary behaviour (≤2 h of recreational screen time), and sufficient sleep (9-11 h for children or 8-10 h for adolescents) each day. The objective of this systematic review was to examine how combinations of physical activity, sedentary time, and sleep duration relate to depressive symptoms and other mental health indicators among children and adolescents. METHODS: Literature was obtained through searching Medline, EMBASE, PsycINFO, and SportDiscus up to September 30, 2019. Peer-reviewed studies published in English or French were included if they met the following criteria: population (apparently healthy children and adolescents with a mean age of 5-17 years), intervention/exposure (combinations of physical activity, sedentary time, and sleep duration), and outcomes (depressive symptoms and other mental health indicators). A risk of bias assessment was completed for all included studies using the methods described in the Cochrane Handbook. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to assess the quality of evidence for each health indicator. Narrative syntheses were employed to describe the results due to high levels of heterogeneity across studies. RESULTS: A total of 13 cross-sectional studies comprised in 10 papers met inclusion criteria. Data across studies involved 115,540 children and adolescents from 12 countries. Overall, the findings indicated favourable associations between meeting all 3 recommendations and better mental health indicators among children and adolescents when compared with meeting none of the recommendations. There was evidence of a dose-response gradient between an increasing number of recommendations met and better mental health indicators. Meeting the screen time and sleep duration recommendations appeared to be associated with more mental health benefits than meeting the physical activity recommendation. The quality of evidence reviewed was "very low" according to GRADE. CONCLUSIONS: The findings indicate favourable associations between meeting all 3 movement behaviour recommendations in the 24-h guidelines and better mental health indicators among children and adolescents. There is a clear need for high-quality studies that use robust measures of all movement behaviours and validated measures of mental health to increase our understanding in this topic area.

Prevalence and correlates of adherence to movement guidelines among urban and rural children in Mozambique: a cross-sectional study.

BACKGROUND: Insufficient physical activity, short sleep duration, and excessive recreational screen time are increasing globally. Currently, there are little to no data describing prevalences and correlates of movement behaviours among children in low-middle-income countries. The few available reports do not include both urban and rural respondents, despite the large proportion of rural populations in low-middle-income countries. We compared the prevalence of meeting 24-h movement guidelines and examined correlates of meeting the guidelines in a sample of urban and rural Mozambican schoolchildren. METHODS: This is cross-sectional study of 9-11 year-old children (n = 683) recruited from 10 urban and 7 rural schools in Mozambique. Moderate- to vigorous-intensity physical activity (MVPA) and sleep duration were measured by waist-worn Actigraph GT3X+ accelerometers. Accelerometers were worn 24 h/day for up to 8 days. Recreational screen time was self-reported. Potential correlates of meeting 24-h movement guidelines were directly measured or obtained from validated items of context-adapted questionnaires. Multilevel multivariable logit models were used to determine the correlates of movement behaviours. Meeting 24-h movement guidelines was defined as ≥60 min/day of MVPA, ≤2 h/day of recreational screen time, and between 9 and 11 h/night of sleep. RESULTS: More rural (17.7%) than urban (3.6%) children met all three 24-h movement guidelines. Mean MVPA was lower (82.9 ± 29.5 min/day) among urban than rural children (96.7 ± 31.8 min/day). Rural children had longer sleep duration (8.9 ± 0.7 h/night) and shorter recreational screen time (2.7 ± 1.9 h/day) than their urban counterparts (8.7 ± 0.9 h/night and 5.0 ± 2.3 h/day respectively). Parental education (OR: 0.37; CI: 0.16-0.87), school location (OR: 0.21; CI: 0.09-0.52), and outdoor time (OR: 0.67; CI: 0.53-0.85) were significant correlates of meeting all three 24-h movement guidelines. CONCLUSIONS: Prevalence and correlates of meeting movement guidelines differed between urban and rural schoolchildren in Mozambique. On average, both groups had higher daily MVPA minutes, shorter sleep duration, and higher recreational screen time than the 24-h movement guidelines recommend. These findings (e.g., higher than recommended mean daily MVPA minutes) differ from those from high-income countries and highlight the need to sample from both urban and rural areas.

Exploring parent-reported barriers to supporting their child's health behaviors: a cross-sectional study.

BACKGROUND: Parents can influence the health behaviors of their children by engaging in supportive behaviors (e.g., playing outside with their child, limiting recreational screen time). How, and the extent to which parents engage in supportive behaviors may be influenced by perceived barriers. The purpose of this study is to explore whether the frequency, and types, of barriers to providing parental support are dependent on the type of child health behavior being supported (i.e., physical activity, recreational screen time reduction, healthy eating, and sleep). METHODS: Study participants were 1140 Ontario parents with at least one child under the age of 18 who completed a Computer Assisted Telephone Interview (CATI) survey about parental support behaviors. Open-ended responses about perceived barriers to parental support were coded, and aggregated to meta-categories adopted from the social-ecological model (i.e., individual child, individual parent, interpersonal, environmental). Freidman rank sum tests were used to assess differences across child behaviors. Wilcoxon rank sum tests with Bonferroni adjustments were used as a post hoc test for significant Freidman results. RESULTS: There were more barriers reported for supporting physical activity than for any other child behavior (ps < .01, As ≥ .53). Parents reported more parent level and environmental level barriers to supporting child physical activity versus other behaviors (ps < .001, As ≥ .55), child level barriers were more frequently reported for supporting healthy eating and sleep (ps < .001, As ≥ .57), and interpersonal barriers were more frequently reported for supporting recreational screen time reduction (ps < .001, As ≥ .52). Overall, parents reported more child and parent level barriers versus interpersonal and environmental barriers to supporting child health. CONCLUSIONS: Parents experience a variety of barriers to supporting their children's health behaviors. Differences in types of barriers across child health behaviors emerged; however, some frequently reported barriers (e.g., child preferences) were common across behaviors. Interventions promoting parental support should consider strategies that can accommodate parents' busy schedules, and relate to activities that children find enjoyable. Creating supportive environments that help facilitate support behaviors, while minimizing parent level barriers, may be of particular benefit. Future research should explore the impact of barriers on parental support behaviors, and effective strategies for overcoming common barriers.

Physical activity, recreational screen time, and depressive symptoms among Chinese children and adolescents: a three-wave cross-lagged study during the COVID-19 pandemic.

BACKGROUND: Longitudinal evidence is lacking on the interplay between lifestyle behaviors and depressive symptoms, especially in the context of the COVID-19 pandemic. This study investigated the changes in physical activity and recreational screen time during the pandemic, along with their reciprocal associations with depressive symptoms among children and adolescents. METHODS: The public health emergency due to the pandemic started in January 2023 and lasted for two months in Shanghai, China. A three-wave longitudinal study was conducted among 1,666 children and adolescents (6-18 years) in January, March, and July 2023. Moderate-to-vigorous intensity physical activity (MVPA), recreational screen time, and depressive symptoms were measured using self-reported questionnaires. Random-intercept cross-lagged panel models were constructed to examine the bidirectional associations between physical activity and recreational screen time with depressive symptoms. RESULTS: Children and adolescents experienced a significant decrease in MVPA and a substantial increase in recreational screen time during the pandemic, which failed to return to pre-pandemic levels post-pandemic. Pre-pandemic MVPA was negatively associated with subsequent depressive symptoms (ß = -0.147). Conversely, pre-pandemic depressive symptoms were positively associated with subsequent recreational screen time (ß = 0.085), which in turn predicted heightened post-pandemic depressive symptoms (ß = 0.076). When stratified by age, significant associations were found in adolescents but not children. CONCLUSIONS: Sustained unhealthy changes in physical activity and recreational screen time were observed during the COVID-19 pandemic among children and adolescents. This study elucidates a potential reciprocal relationship between lifestyle behaviors and mental well-being. Effective interventions are emphasized to counter the negative impacts of insufficient physical activity and excessive screen use on the mental health of children and adolescents.

Physical activity and recreational screen time among Chinese children and adolescents: a national cross-sectional study.

Background: The increasing prevalence of physical inactivity and prolonged Recreational Screen Time (RST) among children and adolescents is emerging as a significant public health concern. This study investigates the current status of Physical Activity (PA) and RST among Chinese children and adolescents from 2017 to 2019. It also examines variations in PA and RST across different school levels, genders, urban-rural areas, regions, and seasons. Methods: A national cross-sectional survey, conducted in China from 2017 to 2019, included 53,101 children and adolescents from grades 4 to 12 (aged 10 to 18 years old). Data on PA and RST were collected via self-administered questionnaires. The study employed descriptive statistics, calculated weighted prevalence rates, and conducted differential analysis across diverse demographic groups. Results: Between 2017 and 2019 in China, merely 28.73% of children and adolescents adhered to World Health Organization's PA guidelines, while 76.09% met China's RST guidelines. Notably, females, higher-grade students, rural residents, and children and adolescents from southern regions exhibited significantly lower levels of PA compared to their male, lower-grade, urban, and northern counterparts. Concurrently, RST was significantly higher among males, lower-grade students, rural residents, and those from northern regions. Seasonal variations were also observed, with lower PA and higher RST in autumn and winter as compared to spring. Conclusion: The study reveals a concerning low level of PA among Chinese children and adolescents, with marked disparities in PA and RST across different groups. This underscores the need for targeted health promotion strategies to enhance PA and mitigate RST among various child and adolescent populations.

Healthier movement behavior profiles are associated with higher psychological wellbeing among emerging adults attending post-secondary education.

BACKGROUND: Emerging adulthood is a stressful time fraught with new challenges while attending higher education. Identifying protective factors to help reduce the psychological burden that many will experience during this period is therefore important. This study aimed to identify whether emerging adults attending post-secondary education can be classified into distinct profiles based on their 24-h movement behaviors, evaluate correlates of profile membership, and examine relationships between profile membership and indicators of mental health. METHODS: This cross-sectional study used data from Cycle 1 of the Canadian Campus Wellbeing Survey. Emerging adults (N = 15,080; 67.6 % female; mean age = 20.78 ± 2.00) from 20 post-secondary institutions in Canada self-reported their movement behaviors - moderate-to-vigorous physical activity (MVPA), recreational screen time (ST) and sleep - and completed measures of psychological distress and mental wellbeing. Latent profile analysis was employed. RESULTS: Five profiles were identified: low ST with very high (12.6 %), high (24.4 %) and low MVPA (51.2 %) as well as high ST with high (2.3 %) and low MVPA (9.4 %). Profiles had similar sleep patterns and were thus characterized by differences in MVPA and ST. Several socio-demographic variables were associated with profile membership. Profiles characterized by healthier combinations of MVPA, ST and sleep generally reported more favorable scores for indicators of mental health. LIMITATIONS: Cross-sectional data limits causal inference, whereas self-reports may be biased. CONCLUSIONS: Campus-based interventions should focus on getting students to engage in a healthy balance of physical activity and recreational screen use as it has the potential to reduce the mental health burden on emerging adults attending post-secondary education.

A Comparison of Meeting Physical Activity and Screen Time Recommendations between Canadian Youth Living in Rural and Urban Communities: A Nationally Representative Cross-Sectional Analysis.

Meeting the physical activity (PA) and recreational screen time recommendations for children and young people is associated with several health benefits. The purpose of this study was to compare the odds of meeting PA and recreational screen time recommendations between the Canadian youth living in urban versus rural communities. We analyzed nationally representative cross-sectional data collected as part of the 2017-2018 cycles of the Canadian Community Health Survey among young people aged 12-17 years. PA and screen time were self-reported. Sex-specific multivariable logistic regression models were used to estimate the odds of meeting individual and combined PA and recreational screen time recommendations by rural and urban status after adjusting for individual, socioeconomic, and seasonal covariates. The odds of meeting the PA recommendation were not statistically significantly different among males (OR = 1.01, 95% CI: 0.86-1.18) or females (OR 1.05, 95% CI: 0.99-1.11) living in urban versus rural communities. The odds of meeting the recreational screen time recommendations were statistically significantly lower among male (OR = 0.71, 95% CI: 0.65-0.77) and female (OR = 0.71, 95% CI: 0.59-0.86) youth living in urban compared to those in rural communities. The odds of meeting the combined PA and screen time recommendations were statistically significantly lower among urban males (OR = 0.75, 95% CI: 0.71-0.81) but not females (OR = 0.82, 95% CI: 0.58-1.15) than those from rural communities. These findings suggest that residential context (i.e., urban versus rural) may have a differential impact on meeting the combined PA and screen time recommendations among the male and female Canadian youth. Future research should investigate these differences using device-based measures.

Recreational Screen Time Use among a Small Sample of Canadians during the First Six Months of the COVID-19 Pandemic.

(1) Background: The coronavirus (COVID-19) pandemic has caused disruptions in the daily lives of individuals in Canada. Purpose: Examine how total and specific (i.e., watching television, using social media, going on the Internet, playing video games, and engaging in virtual social connection) recreational screen time behaviours changed throughout the first six months of the COVID-19 pandemic, in comparison to pre-pandemic levels; (2) Methods: Sixty four Canadians (mostly Caucasian, female, age range = 21-77 years) completed monthly surveys from April to September of 2020; (3) Results: A one-way repeated measures analysis of variance (RM-ANOVA) and subsequent post hoc analysis revealed that total recreational screen time was statistically higher in late March/April (292.5 min/day ± 143.0) and into May, compared to pre-COVID-19 (187.8 min/day ± 118.3), before declining in subsequent months; (4) Conclusions: Generally, specific recreational screen time behaviours, such as time spent watching television, followed the same trend. Future studies with larger sample sizes and from other countries examining recreational screen time behaviours longitudinally over the pandemic are still needed to allow for greater generalizability.

Recreational Screen Time and Anxiety among College Athletes: Findings from Shanghai.

To better understand the behavioral factors contributing to the mental health status among student athletes, we examined the link between recreational screen time and college student athlete's anxieties. This cross-sectional study was conducted among 278 college student athletes from Shanghai, China, aged between 17 and 25 years old (M = 19.4, SD = 1.5). Multivariate regression analyses, controlled for age, gender, rural vs. urban residency, and individual vs. team sports factors, were performed to analyze the association between their average daily recreational screen time in a week and their dispositional anxiety, pre-competition anxiety, and anxiety during competition, which were measured by the Chinese version of validated psychometric scales among athlete population. Significant results were found in both dispositional anxiety and situational anxiety in relation to recreational screen time among college athletes. Conclusions: Our findings indicate that excessive recreational screen time is a risk indicator of college student athletes' dispositional anxiety, pre-competition anxiety, and anxiety during competition.

Clustering of Six Key Risk Behaviors for Chronic Disease among Adolescent Females.

Chronic diseases are the leading cause of disability and mortality globally. In Australia, females are at heightened risk. This research explored the prevalence, patterns, and correlates of six key risk behaviors (physical inactivity, poor diet, recreational screen time, inadequate sleep, alcohol use, and smoking) among adolescent females and whether knowledge of health guidelines was associated with adherence. Adolescent females completed an anonymous online questionnaire (N = 687; Mage = 13.82). Logistic regression assessed the association between knowledge and adherence. A Latent Class Analysis (LCA) and three-step procedure identified risk behavior clusters and their correlates. Despite positive health self-ratings (77% good/very good), most participants reported insufficient moderate-to-vigorous physical activity (MVPA; 89%), vegetable intake (89%), and excessive screen time (63%). Knowledge of guidelines was associated with adherence for MVPA, vegetable intake, sleep, and alcohol abstinence. Three classes emerged: "moderate risk" (76%), "relatively active, healthy eaters" (19%), and "excessive screen users" (5%). These risk-behavior clusters were associated with perceived value of academic achievement and physical wellbeing. Adolescent females commonly perceive they are in good health, despite engaging in unhealthy behaviors. Public health interventions should utilize effective behavior change strategies, adopt a multiple health behavior change approach (MHBC), and be tailored to specific risk profiles and values among females.

School-Level Socioeconomic Status Influences Adolescents' Health-Related Lifestyle Behaviors and Intentions.

BACKGROUND: School-level socioeconomic status (SES) influences on adolescents' lifestyle behaviors is understudied. We examined how school-level SES and sex influence adolescents' health-related lifestyle behaviors and intentions. METHODS: Grade 8 students aged 13-14 years completed an online questionnaire regarding their sociodemographic characteristics, dietary behaviors, physical activity participation and recreational screen-time, and intentions regarding these behaviors. School-level SES, based on an Index of Community Socio-Educational Advantage (ICSEA), was categorized as low or high. Generalized estimating equations estimated individual-level summary statistics, adjusted for clustering. RESULTS: Students (N = 2538; response rate = 79%) from 23 high schools (low ICSEA = 16) participated. Compared with low ICSEA students, high ICSEA students were more likely to report eating breakfast daily (OR 1.9 [95% CI 1.5, 2.4]), not drinking sugar-sweetened beverages (SSBs) daily (2.9 [1.9, 4.3]), and were more likely to have intentions to eat breakfast (1.8 [1.3, 2.3]) and ≥ 5 vegetable serves (1.2 [1.0, 1.5]) daily. Boys were more likely than girls to meet recommendations for breakfast eating, vegetable intake, moderate-to-vigorous physical activity and screen-time, but boys were less likely to meet recommendations regarding SSB intake. CONCLUSIONS: Students from low ICSEA schools would benefit from additional support to improve dietary-related behaviors and intentions. More research is required to identify what targeted approaches will address sex differences in adolescents' lifestyle behaviors.

From awareness to action: Effects of a school-based intervention on TV viewing behavior stages and screen time guidelines knowledge in Brazilian adolescents / Da conscientização à ação: Efeitos de uma intervenção escolar nos estágios de mudança de comportamento para assistir TV e no conhecimento das diretrizes de tempo de tela em adolescentes brasileiros

The aims of the study were to verify the effect of an intervention on the stage of behavior change for TV viewing and to identify the possible mediating role of knowledge on screen time guidelines among Brazilian students. This study is a multicomponent school-based intervention conducted with 727 students (54.3% female, 13 years; 427 in the intervention group and 300 in the control group). The intervention was performed in 2017 with baseline and post-intervention assessments (over one academic year). Teacher training was carried out at the beginning of the intervention along with en-vironmental improvements, while educational curriculum such as the delivery of folders and posters were performed throughout the year. The stages of behavior change for TV viewing and knowledge of screen time guidelines were measured by a self-reported questionnaire and the structural equation modeling approach was performed. The intervention had no significant effects on stages of behavior change for TV (p = 0.744) nor did it result in significant changes on knowledge of screen time guide-lines (p = 0.741). While there was no mediation between knowledge of screen time guidelines and the effect of the intervention on stages of behavior change for TV (95%CI: -0.45;0.63), an associa-tion was found between knowledge of screen time guidelines and stages of behavior change for TV (p<0.001). In conclusion, intervention had no significant effect on the stages of behavior change for TV and no mediating effect was observed. However, enhancing awareness on screen time guidelines may positively impact the adolescent's intention to reduce TV time

Os objetivos do estudo foram verificar o efeito de uma intervenção nos estágios de mudança de comporta-mento para assistir TV e identificar o papel mediador do conhecimento sobre as recomendações de tempo de tela. A intervenção multicomponente, randomizada e controlada obteve a participação de 727 alunos em 2017 (54,3% meninas, 13 anos; 427 no grupo intervenção e 300 no grupo controle). A formação dos pro-fessores foi realizada no início da intervenção juntamente com as melhorias ambientais, enquanto as ações educativas foram realizadas ao longo do ano. Os estágios de mudança de comportamento para assistir TV e o conhecimento sobre as recomendações do tempo de tela foram mensurados por questionário auto reportado, pré e pós-intervenção (um ano letivo). Para análise dos dados foi realizada uma modelagem de equações estru-turais. Não houve efeito da intervenção nos estágios de mudança de comportamento para TV (p = 0,744) e também não houve mudanças significativas no conhecimento dos estudantes sobre as recomendações do tempo de tela (p = 0,741). Embora não tenha havido mediação entre conhecimento das recomendações do tempo de tela e o efeito da intervenção nos estágios de mudança de comportamento para TV (IC95%: -0,45;0,63), foi encontrada associação entre o conhecimento das recomendações e os estágios de mudança de comportamento para TV (p < 0,001). Conclui-se que a intervenção não teve efeito significativo nos estágios de mudança de comportamento para TV e efeito mediador. No entanto, aumentar a conscientização sobre as recomendações de tempo de tela pode impactar positivamente na intenção do adolescente de reduzir o tempo de TV

Screen-Based Behaviors of Adolescents in Bangladesh.

BACKGROUND: The time spent by adolescents in electronic screen-based activities has been associated with obesity and other adverse health outcomes; however, little is known about screen-based behaviors in Asian adolescents. The purpose of this study was to describe the prevalence, patterns, and correlates of recreational screen-based behaviors among adolescents in Bangladesh. METHODS: A total of 758 students (52% girls), aged 13 to 16 years, from 8 secondary schools of Dhaka city, Bangladesh, completed a survey in which the Adolescent Sedentary Activity Questionnaire was used to collect information on screen time. Total screen time was categorized as ≤2 h/day (low) or >2 h/day (high). RESULTS: Approximately 79% of the adolescents had high recreational screen time, with similar values for boys (78%) and girls (80%). Median reported recreational screen time was 4.0 h/day; boys had longer times (4.3 h/day) than girls (3.6 h/day). Multivariable analyses showed that high screen time was more common among boys than girls and was positively associated with commuting to school by car, consumption of fast food ≥3 times/week, having sleep disturbance, and high family income. CONCLUSIONS: This study identified high rates of recreational screen time among urban adolescents in Bangladesh and specific correlates of prolonged screen time; the results underscore the need to develop pragmatic strategies to reduce sedentariness among adolescents in Bangladesh.