Tracking and predictors of screen time from early adolescence to early adulthood: a 10-year follow-up study

Correlates of screen time in the early years (0-5 years): A systematic review

The majority of young children engage in high levels of screen time. To inform future interventions, knowledge on correlates of screen time is important. This review expands on previous work by focusing on the entire early childhood range, and including a broad focus regarding types of correlates and screens. A literature search (PubMed, Embase, PsycINFO, SPORTDiscus) was performed from 2000 up to October 2021. Included studies (cross-sectional and prospective) examined associations between a potential correlate and screen time (duration or frequency) in typically developing, apparently healthy children aged 0-5 years. Methodological quality was assessed by two independent researchers. Fifty-two of 6,614 studies were included. Two studies had high methodological quality. We found moderate evidence for a positive association between an electronic device in the bedroom, parental screen time, having a TV on at home, descriptive norms and screen time, and a negative association between sleep duration, household features, high value on physical activity, monitoring screen time, being in childcare, parental self-efficacy and screen time. We found no evidence for an association for child sex, body mass index, physical activity, temperament, number of siblings, being a first-born, neighborhood-related factors, socio-economic indicators, and parental marital status, physical activity, weight status, depression, wellbeing, sex, age and positive outcome expectations. The evidence for other investigated correlates was inconsistent or insufficient. Despite the evidence for moderate associations, we were unable to draw strong conclusions. More high-quality research is needed to identify correlates of screen time in early childhood.

A Narrative Review of Screen Time and Wellbeing among Adolescents before and during the COVID-19 Pandemic: Implications for the Future

The COVID-19 pandemic has disrupted the lives of many. In particular, during the height of the pandemic, many experienced lockdowns, which in turn increased screen time drastically. While the pandemic has been declared an endemic and most activities have been reinstated, there appears to still be elevated screen time among adolescents due to poor habits formed during the pandemic lockdowns. This paper explores the factors by which screen time affects well-being among adolescents and how the pandemic may have influenced some of these factors. For example, beyond having greater screen time, many adolescents have also reduced their physical activities and picked up poor sleeping habits. These findings highlight the importance of having integrated activity guidelines that go beyond limiting adolescents' daily screen time. It is important to affirm that beyond ensuring that adolescents limit their daily screen time, they are also meeting physical activity and sleep guidelines so that they achieve a holistic sense of wellbeing.

Study protocol for an effectiveness-implementation hybrid trial to evaluate a health promotion intervention in parents and their 5-year-old child: Saga Stories in health talks in Swedish child healthcare

BACKGROUND

Unhealthy lifestyle behaviours such as a poor diet, inadequate physical activity, and excessive screen time have been shown to be established in childhood and track into adulthood, demonstrating the need for health promotion interventions in the pre-school years. The overall aim of this project is to: (i) evaluate the effectiveness of `Saga Stories in health talks´ within child healthcare (CHC) on parental self-efficacy to promote healthy diet, physical activity, and screen time behaviours in their child; children's intake of key dietary indicators and screen time and (ii) evaluate and explore the implementation of `Saga Stories in health talks´ with regards to acceptability, appropriateness, feasibility, fidelity, adoption, sustainability, satisfaction, and usage.

METHODS

A hybrid type I effectiveness-implementation trial will be conducted. A cluster randomized controlled trial will be used to assess the effectiveness of `Saga Stories in health talks´ in 42 CHC centers across six regions in Sweden. `Saga Stories in health talks´ consists of material for CHC nurses to use to facilitate the health talk with both the child and parent(s) and is complemented with take-home material. Parent and child dyads are recruited (n = 450) from participating CHC centers when they attend their 5-year routine visit. The intervention group receives the health talk using Saga Stories and take-home material, whereas the control group receives the standard health talk. The primary outcome is parental self-efficacy to promote healthy diet, physical activity, and screen time behaviours in their child and secondary outcomes include children's intake of key dietary indicators and screen time. All outcomes are assessed at baseline and 2-months post-intervention. The implementation outcomes that will be assessed are: acceptability, appropriateness, feasibility, satisfaction, usage, fidelity, adoption, and sustainability (assessed quantitatively and qualitatively).

DISCUSSION

The Swedish National Board of Health and Welfare have identified the need of more material, education, and working methods for promoting healthy lifestyle behaviours in CHC. Following this trial `Saga Stories in health talks´ has great potential to be implemented in CHC across Sweden to aid nurses to promote and support healthy lifestyle behaviours in pre-school children and their families.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT05237362 . Registered 2 February 2022.

Cross-sectional associations between screen time and the selected lifestyle behaviors in adolescents

Background

In adolescents, excessive screen time leads to many adverse health outcomes and is associated with a variety of lifestyle behaviors. This study was conducted to investigate the associations between the two types of screen time and a variety of lifestyle behaviors in American adolescents.

Methods

Based on the Youth Risk Behavior Surveillance System, this cross-sectional study was conducted. With the help of data collectors, participants self-reported screening time, lifestyle behaviors, and demographic data via well-validated tools.

Results

19% and 43.4% of the participants spent more than two hours a day watching television and using the computer, respectively, while the prevalence of physical inactivity and insufficient sleep was 75.1 and 74.4% respectively. Furthermore, 11.9, 7.3, 14.3, and 21.3% of the participants reported skipping fruits, vegetables, breakfast and milk, respectively. Moreover, the prevalence of alcohol and tobacco consumption and sexual activity was 26.8, 5.3, and 23.5% respectively. More than two hours of television time was significantly associated with high risks of fewer frequency for eating fruit (OR = 1.605, 95%CI: 1.308-1.970), vegetables (OR = 1.389, 95%CI: 1.029-1.873), and smoking (OR = 1.465, 95%CI: 1.088-1.972). Computer/video time for more than two hours was significantly associated with high risks of physical inactivity (OR = 1.724, 95%CI: 1.531-1.941), insufficient sleep (OR = 1.354, 95%CI: 1.151-1.592), and not eating fruit (OR = 1.434, 95%CI: 1.179-1.745).

Conclusion

Increased screen time may be associated with specific unhealthy lifestyle behaviors in adolescents. Furthermore, the associations between different types of screen time and various lifestyle behaviors varied.

Physical Education and Physical Activity Promotion: Lifestyle Sports as Meaningful Experiences

The value of embracing a physically active lifestyle has been well documented in recent times. However, despite this knowledge, physical activity levels in many western societies remain worryingly low in both adult and youth populations. Habit formation in youth is a key indicator of engagement in physical activity as an adult; therefore, maximising opportunities to develop motivation in young people is vitally important to increase the likelihood of maintaining physical activity habits as an adult. A key factor for the development of motivation is school-based physical education. This review considers the current landscape of physical education as a vehicle for physical activity promotion, and suggests that a change of approach that moves away from physical education focusing solely on sport techniques is long overdue. A culturally relevant curriculum that includes lifestyle sports, with a focus on mastery and enjoyment through a meaningful experiences approach, is proposed as a viable update to current practice.

Effects of Movement Behaviors on Overall Health and Appetite Control: Current Evidence and Perspectives in Children and Adolescents

PURPOSE OF REVIEW

To present the definitions and recommendations for movement behaviors in children and adolescents, including physical activity (PA), sedentary behaviors (SB), and sleep, and to provide an overview regarding their impact on health and obesity outcomes from childhood to adulthood, as well as interactions with appetite control.

RECENT FINDINGS

PA represents a variable proportion of daily energy expenditure and one can be active with high SB or vice versa. Studies have described movements across the whole day on a continuum from sleep to SB to varying intensities of PA. More PA, less SB (e.g., less screen time) and longer sleep are positively associated with indicators of physical health (e.g., lower BMI, adiposity, cardiometabolic risk) and cognitive development (e.g., motor skills, academic achievement). However, less than 10% of children currently meet recommendations for all three movement behaviors. Movement behaviors, adiposity, and related cardiometabolic diseases in childhood track into adolescence and adulthood. Furthermore, low PA/high SB profiles are associated with increased energy intake. Recent studies investigating energy balance regulation showed that desirable movement behavior profiles are associated with better appetite control and improved eating habits. Early identification of behavioral phenotypes and a comprehensive approach addressing all key behaviors that directly affect energy balance will allow for individual strategies to prevent or treat obesity and its comorbidities. Investigating exercise as a potential "corrector" of impaired appetite control offers a promising weight management approach.

Association of mentally-active and mentally-passive sedentary behaviour with depressive symptoms among adolescents

BACKGROUND

The evidence on the association between sedentary behaviour and depression in adolescence is mixed. We aimed to investigate the association between mentally-active and mentally-passive sedentary behaviours at 11 years (11y) and depressive symptoms at 14y, and to examine potential mediators.

METHODS

UK Millennium Cohort Study data were used (n=7,124; 49% boys). At 11y, participants self-reported frequency of mentally-passive (listening to music, internet use) and mentally-active sedentary behaviours (reading, playing electronic games). Additional parental-reported behaviours (mentally-passive: TV viewing; mentally-active: homework) were summed with self-reported behaviours to represent continuous indicators of mentally-active and mentally-passive sedentary behaviour. Depressive symptoms were assessed (at 11y and 14y) using the short-version of Mood and Feelings Questionnaire. Body mass index (BMI), mentally-passive sedentary behaviour and cognition at 14y were examined as potential mediators. Linear regression models were adjusted for confounders and stratified by sex. Subsequent mediation analyses reporting e-values were used to assess unmeasured confounding.

RESULTS

Among girls, mentally-passive sedentary behaviour at 11y was associated with later depressive symptoms (14y) [β:0.089 (95%CI:0.055-0.122), e-value:1.32]. This association was mediated by BMI [5.6% (95%CI:4.1%-8.6%)] and mentally-passive sedentary behaviour [105.6% (95%CI:79.6%-156.7%)]. No associations were observed in boys or between mentally-active sedentary behaviour and later depressive symptoms.

LIMITATIONS

The parental report of behaviours and the assessment of mediators and outcome in the same wave are the main limitations.

CONCLUSION

Future interventions aiming to improve mental health among girls could aim to reduce mentally-passive sedentary behaviour in early teens and could target potential mediators including BMI.

Associations between mentally-passive and mentally-active sedentary behaviours during adolescence and psychological distress during adulthood

It is unclear if different types of sedentary behaviour during the adolescence are differentially associated with psychological distress during adolescence and adulthood. It is also unknown what may mediate this potential proposed association. The current study aimed to analyse the association of mentally-active and mentally-passive sedentary behaviours during adolescence (16y) with subsequent psychological distress during adulthood (42y), and to examine the role of potential mediators (42y). Data from the 1970 British Cohort Study was used (N = 1787). At age 16y participants reported time and frequency in mentally-passive (TV-viewing and watching movies) and mentally-active (reading books, doing homework and playing computer games) sedentary behaviours, psychological distress and organized sports participation. At 42y, participants reported cognition (vocabulary test), TV-viewing, psychological distress, self-rated health, body mass index and employment status. Education was collected throughout the follow-up years. Logistic regression and mediation models assessed associations. Multiple imputation using chained equations was used to assess the impact of missing data. Mentally-passive sedentary behaviour in adolescence was a risk factor for psychological distress during adulthood in complete-cases analysis [OR:1.44(95%CI:1.09-1.90)], which was confirmed by the model with multiple imputation. Mentally-active sedentary behaviour at 16y was not associated with psychological distress at 42y. Adult TV-viewing during weekends (24.7%), and self-rated health (19.0%) mediated the association between mentally-passive sedentary behaviour during adolescence and psychological distress during adulthood. However, the mediation was not clear in the models with multiple imputation. Mentally-passive sedentary behaviour during adolescence was associated with elevated psychological distress during adulthood and this association was mediated TV-viewing and self-rated health in adulthood.

Screen-based behaviors in Australian adolescents: Longitudinal trends from a 4-year follow-up study

The longitudinal trends of screen time, a highly prevalent behavior in adolescents, are relatively unknown. This study examined longitudinal trends in screen time among a large sample of Australian primary school-aged children transitioning into secondary school-aged adolescence. Data were derived from the Longitudinal Study of Australian Children (LSAC). In 2010, 2179 children (49.7% boys; 10.3 ± 1.1 years) completed a time-use diary, recording their main activities during waking hours. This was repeated with the same sample in 2012 (12.4 ± 0.5 years) and 2014 (14.4 ± 0.5 years). Data were analyzed for time spent in TV viewing, computer use, electronic gaming, and social networking and online communication. Repeated-measures MANCOVA tests were performed to analyze trends in screen time. Trends were also analyzed by sex. Total screen time significantly increased (+85.9 min/day) over four years (η_p² = 0.010, P < .001), but differed by sex, with a larger increase in boys (boys: +41.6, girls: +22.7 min/day). Electronic gaming increased in boys (+43.2 min/day) and decreased in girls (-16.8 min/day). In contrast, girls reported larger increases in TV viewing (boys: +0.4, girls: +29.1 min/day), computer use (boys: +24.8, girls: +34.3 min/day) and time communicating online and social networking (boys: +4.3, girls: +15.2 min/day). To conclude, screen time among adolescents increases between the ages of 10 and 14 years, but differs by sex and screen time domain. Future screen time reduction interventions may choose to focus on recreational computer use and electronic gaming in boys and TV viewing and time spent communicating online and social networking for girls.

Latin American interventions in children and adolescents' sedentary behavior: a systematic review

OBJECTIVE To identify and evaluate the effects of community-based interventions on the sedentary behavior (SB) of Latin American children and adolescents. METHODS A systematic review on community-based trials to reduce and/or control SB in Latin American countries (Prospero: CRD42017072157). Five databases (PubMed, Web of Science, Scopus, SciELO and Lilacs) and a reference lists were searched. RESULTS Ten intervention studies met the eligibility criteria and composed the descriptive synthesis. These studies were conducted in Brazil (n=5), Mexico (n=3), Ecuador (n=1) and Colombia (n=1). Most interventions were implemented in schools (n=8) by educational components, such as meetings, lessons, and seminars, on health-related subjects (n=6). Only two studies adopted specific strategies to reduce/control SB; others focused on increasing physical activity and/or improving diet. Only one study used an accelerometer to measure SB. Seven studies investigated recreational screen time. Eight studies showed statistically significant effects on SB reduction (80%). CONCLUSIONS Latin America community-based interventions reduced children and adolescents' SB. Further studies should: define SB as a primary outcome and implement strategies to reduce such behaviour; focus in different SBs and settings, other than recreational screen time or at-home sitting time; and use objective tools together with questionnaires to measure sedentary behaviour in.

Determinants of Physical Activity and Screen Time Trajectories in 7th to 9th Grade Adolescents-A Longitudinal Study

Physical activity (PA) in youth tends to decline with increasing age, while sedentary behaviour including screen time (ST) increases. There are adolescents, however, whose PA and ST do not follow this pattern. The aim of this study is (i) to examine trajectories in PA and ST from grade 7-9 among students in Berlin, and (ii) to investigate the relationship of these trajectories with individual factors and school type. For the present analyses, changes in students' PA and ST across three time points from 7th to 9th grade were assessed via self-report questionnaires. Positive and negative trajectories were defined for both PA (positive: increasing or consistently high, negative: decreasing or consistently low) and ST (vice versa). Multivariable logistic regression analyses were performed to identify possible predictors of PA and ST trajectories. In total, 2122 students were included (50.2% girls, mean age 12.5 (standard deviation 0.7) years). Compared to grade 7, less students of grade 9 fulfilled PA and ST recommendations (PA: 9.4% vs. 13.2%; ST: 19.4% vs. 25.0%). The positive PA trajectory included 44% of all students (63% boys), while the positive ST trajectory included 21% of all students (30% boys). Being a boy was significantly associated with a positive PA trajectory, while being a girl, having a high socioeconomic status, and attending a high school, were significantly associated with a positive ST trajectory. Different PA and ST trajectories among adolescents should be taken into account when implementing prevention programs for this target group.

Tracking of Physical Activity and Sedentary Behavior From Adolescence to Young Adulthood: A Systematic Literature Review

PURPOSE

The transition from adolescence to young adulthood is categorized by substantial changes in one's activity behaviors, which may have important implications for health. To date, no reviews have systematically investigated the evidence of tracking for both physical activity (PA) and sedentary behavior (SB) specifically during this transition period.

METHODS

Web of Science, PubMed, SPORTDiscus, PsycINFO, and CINAHL were searched for articles that examined the tracking of PA and SB in adolescents (aged 9-18 years) through young adulthood (aged 19-25 years) published between the years of 2000 and 2018. Studies were also compared on methodologic quality.

RESULTS

Sixteen studies met the inclusion criteria. The tracking correlations for both the frequency and duration of PA were low-to-moderate. Gender differences were observed in the tracking of PA frequency and duration. Studies that examined the tracking of SB were less frequent, making it difficult to determine how SB tracks from adolescence to young adulthood.

CONCLUSIONS

Generally, PA was shown to track moderately from adolescence through young adulthood. The lack of studies reporting on the tracking of SB indicates that this area should be a target for future research. Future tracking studies should consider appropriate gold-standard objective methodologies and statistical analysis techniques that report fixed outcomes.

Longitudinal Sedentary Time Among Females Aged 17 to 23 Years

INTRODUCTION

Time spent in sedentary behaviors is a newer risk factor for poor cardiometabolic health. This study examined longitudinal correlates of sedentary time among a cohort of females from about age 17 to age 23 years.

METHODS

The cohort included females originally participating in the Trial of Activity for Adolescent Girls Maryland site who had assessments in 2009 and 2015 (n=431). Percentage daily time in sedentary behaviors was determined from accelerometers. Sociodemographics, psychosocial factors, and health behaviors were assessed by questionnaire. Lasso variable selection identified potential variables included in linear mixed effects models. As a secondary analysis, a k-means algorithm for longitudinal data identified homogeneous clusters of individual sedentary time trajectories.

RESULTS

Percentage daily sedentary time did not change over time (67% to 68%). Not of black race (p=0.04), higher father's education (p<0.001), more weekday computer hours (p<0.001), more weekend TV hours (p=0.01), more physical activity barriers (p=0.003), fewer days per week driving (p=0.01), and more vehicles in the household (p=0.02) were associated with greater sedentary time. Cluster analysis resulted in two patterns: more (70%) versus less (60%) time being sedentary. The more sedentary individuals were more likely to be college graduates (p<0.001), have a higher income (p=0.03), and work fewer hours (p=0.009). They were also less likely to be married or in a common-law relationship (p=0.05) or in a parenting role (p=0.02).

CONCLUSIONS

Time spent in sedentary behaviors remained stable. Factors associated with sedentary time were significant across the socioecologic framework and included several factors indicating higher SES.

An activity-friendly environment from the adolescent perspective: a concept mapping study

Background

In today’s society, few adolescents meet physical activity guidelines and effects of physical activity promoting programmes are disappointing. In studies exploring determinants of physical activity, the perspective of adolescents themselves is largely lacking. Also, there is a lack of knowledge on potential environmental determinants of adolescent physical activity. Therefore, this study aimed to explore adolescents’ perspectives on characteristics of an activity-friendly environment.

Methods

Concept mapping meetings were conducted with four secondary school classes, including 115 adolescents (13–17 years). Each student generated ideas regarding the characteristics of an activity-friendly environment. For each school class, ideas were combined and identical ideas were removed. Next, students individually sorted all ideas, based on self-perceived similarity, and rated their importance on a five-point Likert-scale. A concept map was created for each school class using multidimensional scaling and hierarchical cluster analysis. Finally, the researchers named the potential environmental determinants within the clusters.

Results

The concept maps depicted 23 unique potential determinants of activity friendliness, of which 15 were similar across all school classes. Potential determinants were categorized in the physical-, social-, economic-, and motivational domain. The most frequent and important adolescent-perceived determinants of activity friendliness across all school classes belonged to the physical domain, e.g. a suitable area including a proper surface for a variety of sports, and good lighting in the playground.

Conclusions

Our findings show that adolescents perceive potential determinants in the physical and economic domain as most important for activity friendliness, indicating that future interventions might benefit from targeting potential determinants within these domains.

Electronic supplementary material

The online version of this article (10.1186/s12966-018-0733-x) contains supplementary material, which is available to authorized users.

Integrating sedentary behavior in the theoretical model linking childhood to adulthood activity and health? An updated framework

About 30 years ago, Blair and collaborators proposed a theoretical model illustrating the relationships between childhood and adulthood physical activity and health. The evolution of our societies has led to a "sedentarisation" of the subsequent generations, and the literature underlines an independent effect of physical activity and sedentary behaviors on health. We propose here an updated version of the model first designed by Blair and colleagues, suggesting the integration of the impact of sedentary behaviors on children and adult health.

Screen time behaviours and caffeine intake in US children: findings from the cross-sectional National Health and Nutrition Examination Survey (NHANES)

BACKGROUND

Screen time (ST) behaviours, for example, television (TV) watching and computer use, among youth are associated with unhealthy eating, and these patterns track over time. A positive association between ST and TV watching with consumption of caffeinated foods and beverages has been described in national samples of children in a few European countries. The association of ST behaviours with caffeine intake has not been previously reported. We examined whether ST behaviours were associated with caffeine intake on a given day (% consumers and amount consumed) in a nationally representative sample of US children.

METHODS

Data on 3421 children (ages 6-11 years) from the cross-sectional National Health and Nutrition Examination Survey 2007-2012 were used. Time spent on TV watching and computer use was determined using questionnaires. Dietary intake was assessed using a 24-hour recall by trained interviewers. Caffeine intake (mg) was estimated by using updated food and nutrient databases. Caffeine consumption was examined in relation to time spent (≥2 vs<2 hours/day) on ST behaviours.

RESULTS

Children who watched TV ≥2 hours/day had significantly higher (~45% more) caffeine intake. Total ST or computer use was not associated with caffeine consumption in school-aged children.

CONCLUSION

TV watching was positively associated with caffeine intake in school-aged children, suggesting the need for continued monitoring of ST and caffeine intake behaviours in children and adolescents as well as examining the correlates of these behaviours to inform nutrition and health policies.

Prevalence of high screen time and associated factors among students: a cross-sectional study in Zhejiang, China

OBJECTIVE

To investigate the prevalence and correlates of high screen time (ST) among students in Zhejiang, China.

DESIGN

Cross-sectional study.

SETTING

School-based adolescent health survey in Zhejiang Province, China.

PARTICIPANTS

23 543 students in grades 7-12 from 442 different schools.

OUTCOME

High ST.

RESULTS

The mean age of the students was 15.6 years and 49.7% of them were girls. The prevalence of high ST (screen viewing ≥2 hours per day) was 42.4% (95% CI 40.2% to 44.5%), higher in boys than in girls (45.4%(95% CI 42.8% to 48.0%) vs 39.1% (95% CI 36.6% to 41.7%)). No statistically significant difference was found between urban and rural areas (43.0% (95% CI 37.2% to 48.7%) vs 42.1% (95% CI 39.6% to 44.6%)). The prevalence of high ST among middle school, academic high school and vocational high school students was 35.3%, 30.0% and 73.5%, respectively. Multivariable logistic analysis showed that older age, attendance at vocational high school, non-intact family, poor academic performance, bad self-reported health status, loneliness and drinking carbonated beverages ≥3 times every day were positively associated with high ST. Attendance at academic high school, higher parental education and being physically active were negatively associated with high ST.

CONCLUSIONS

High ST was prevalent among students and associated with a cluster of sociodemographic and behavioural risk factors in Zhejiang, China.

Effects of prenatal exposure to cigarettes on anthropometrics, energy intake, energy expenditure, and screen time in children

BACKGROUND

Maternal prenatal smoking is associated with downstream childhood obesity. Although animal research suggests reduced resting energy expenditure (REE), decreased physical activity (PA), and increased energy intake as mechanisms, these relationships are unclear in humans. The objectives were to examine the association of prenatal maternal smoking with non-volitional energy expenditure (REE and the thermic effect of feeding [TEF]), child adiposity, energy intake, free-living PA (daily light PA (LPA), daily moderate-to-vigorous PA (MVPA), daily sedentary behavior (SB)), and screen time (television and computer/video game) in children.

METHODS

As part of a longitudinal study, 46 children (n = 27 controls and n = 19 smoking exposed) with mean age 7.6 ± 2 years were recruited. Body weight and composition (Bioelectrical Impedance), height (Stadiometer), waist circumference (cm; tape), BMI (kg/m²), REE (kcal/day; indirect calorimetry), PA (minutes; Accelerometry), screen time (hours; self-report) and ad libitum energy intake (lunch buffet; 7-day food log) were measured. Effects sizes were evaluated using Cohen's d.

RESULTS

Relative to controls, after controlling for age and family income, children who were exposed to cigarette smoke in utero exhibited greater waist circumference (p = 0.04, Cohen's d = 1.03), percent body fat (%BF; p = 0.02, Cohen's d = 0.97), and a trend for BMI (p = 0.05, Cohen's d = 0.86). Exposed children did not differ in REE (trend for lower: p = 0.1, Cohen's d = 0.42) or TEF but were shown to have significantly higher ad libitum energy intake (p = 0.02, Cohen's D = 0.70) from the palatable lunch buffet, but not from the out of laboratory 7-day energy intake (p = 0.8). Examining screen time behaviors, exposed children spent more time watching television during the week (p = 0.03, Cohen's D = 0.82), and overall television watching (p = 0.02, Cohen's D = 0.80); there were no group differences in any other screen time behaviors.

CONCLUSIONS

Children exposed to cigarette smoke in utero exhibit greater adiposity, and this exposure may have as contributing factors higher screen time, ad libitum energy intake, and a trend for reduced REE. The data suggest that lifestyle factors such as diet and screen time represent targets for obesity prevention in a high-risk population of young children exposed to prenatal cigarette smoke. Findings also highlight the need for smoking cessation programs to reduce downstream obesity in offspring.

Regional Socioeconomic Inequalities in Physical Activity and Sedentary Behavior Among Brazilian Adolescents

Background: This study aims to describe the regional prevalence and patterns of physical activity (PA) and sedentary behavior among Brazilian adolescents. Methods: Data from the Brazilian Scholar Health Survey, a nationally representative survey of ninth-grade adolescents [mean age: 14.29 y (14.27–14.29)] conducted in 2015 (n = 101,445), were used. Outcomes were television viewing, sitting time (ST), total PA, and active traveling collected via self-administered questionnaire. Information on frequency of physical education classes and type of school was collected from the school’s director. Frequencies with 95% confidence intervals were used to determine the prevalence and patterns of outcomes. Results: Higher prevalence of PA (≥300 min/wk) and ST (>4 h/d) was found in Midwest (PA = 38.0%; ST = 44.5%), South (PA = 37.6%; ST = 50.1%), and Southeast (PA = 36.1%; ST = 49.3%) compared with Northeast (PA = 29.7%; ST = 36.9%) and North (PA = 34.4%; ST = 34.8%) regions of Brazil. ST was higher among adolescents from private schools (51.5%) than public schools (42.9%), whereas active traveling was greater among students of public schools than private schools (62.0% vs 34.4%). Most inequalities in outcomes between capital and interior cities were in the poorest regions. Conclusions: The results indicate that national plans targeting regional inequalities are needed to improve PA and to reduce sedentary behavior among Brazilian adolescents.

The Effect of the Presence of an Internet-Connected Mobile Tablet Computer on Physical Activity Behavior in Children

BACKGROUND

Mobile Internet-connected electronic devices provide access to activities that have traditionally been associated with sedentary behavior. Because they are portable, these devices can be utilized in any environment. Therefore, providing children with access to these devices in environments that typically promote physical activity may result in a reduction in physical activity behavior.

PURPOSE

To assess children's physical and sedentary (ie, sitting) activity with and without the presence of a mobile Internet-connected tablet computer.

METHODS

A total of 20 children [6.7 (1.9) y old] participated in 2 simulated recess conditions in a gymnasium on separate days. During each condition, children had free-choice access physical activity options and a table of sedentary activities for 40 minutes. During 1 session, the iPad was present, and in the other session, it was not. Physical activity was monitored via an accelerometer, and sedentary time was monitored via a stopwatch.

RESULTS

Children significantly (P ≤ .03) reduced average physical activity intensity and increased their sedentary behavior with the iPad present [4.4 (4.0) metabolic equivalents/min and 20.9 (12.4) min sitting] versus the condition without the iPad present [5.3 (4.0) metabolic equivalents/min and 13.6 (13.2) min sitting].

CONCLUSION

Introducing an mobile Internet-connected tablet computer into a gymnasium reduced children's physical activity intensity by 17% and increased sedentary behavior by 54%.

Trends in Screen Time Behaviours in Czech Schoolchildren between 2002 and 2014: HBSC Study

OBJECTIVE

Screen-based behaviours such as watching television or computer use are among the most prevalent sedentary behaviours adolescents spend time on. There is a lack of recent estimates on prevalence and changes in the amount of time spent on screen-based behaviour across Central and Eastern Europe. The main aim is to assess the trends in the prevalence of current recommendations for the screen time (≤2 hours per day) of school-aged children in the Czech Republic between 2002 and 2014.

METHODS

We used an internationally established methodology based on the Health Behaviour in School-aged Children (HSBC) study. Data was derived from Czech national representative samples of 11-, 13- and 15-year-olds collected in the years 2002 (N=4,065), 2006 (N=4,170), 2010 (N=3,962) and 2014 (N=4,338).

RESULTS

The results indicated that the boys and girl surveyed in 2014 are up to two times more likely to meet the current recommendations for watching television in comparison with groups of schoolchildren of the same age surveyed in 2002. In contrast, computer use by adolescents increased markedly between 2006 and 2014. Taking total screen time into account, spending two hours per day or less on it decreased significantly among boys (OR=0.74, 95% CI=0.62-0.89) and girls (OR=0.80, 95% CI=0.70-0.92) between 2006 and 2014.

CONCLUSIONS

As screen time is an important indicator of time spent in a sedentary way, our findings call for more interventions to reduce the time that school-aged children spend in front of screens.

Perceptions of Using Sit-to-Stand Desks in a Middle School Classroom

The purpose of this study was to explore the feasibility of sit-to-stand desks in a middle school classroom. Participants used sit-to-stand desks during health class. Momentary time sampling was used for physical activity and behavioral observations. Results indicate students sat 37%, stood 59%, and walked 4% of the time. Misbehaviors occurred 4% of the observed period. The following themes emerged: focus, freedom, distractions, and design. Sit-to-stand desks appear to encourage standing during instruction while simultaneously limiting misbehaviors. Students indicated some distractions but were generally positive toward desk implementation and suggested they supported learning behaviors. The teacher echoed most of the student themes.

Understanding differences between summer vs. school obesogenic behaviors of children: the structured days hypothesis

BACKGROUND

Although the scientific community has acknowledged modest improvements can be made to weight status and obesogenic behaviors (i.e., physical activity, sedentary/screen time, diet, and sleep) during the school year, studies suggests improvements are erased as elementary-age children are released to summer vacation. Emerging evidence shows children return to school after summer vacation displaying accelerated weight gain compared to the weight gained occurring during the school year. Understanding how summer days differ from when children are in school is, therefore, essential.

DISCUSSION

There is limited evidence on the etiology of accelerated weight gain during summer, with few studies comparing obesogenic behaviors on the same children during school and summer. For many children, summer days may be analogous to weekend days throughout the school year. Weekend days are often limited in consistent and formal structure, and thus differ from school days where segmented, pre-planned, restrictive, and compulsory components exist that shape obesogenic behaviors. The authors hypothesize that obesogenic behaviors are beneficially regulated when children are exposed to a structured day (i.e., school weekday) compared to what commonly occurs during summer. This is referred to as the 'Structured Days Hypothesis' (SDH). To illustrate how the SDH operates, this study examines empirical data that compares weekend day (less-structured) versus weekday (structured) obesogenic behaviors in U.S. elementary school-aged children. From 190 studies, 155 (~80%) demonstrate elementary-aged children's obesogenic behaviors are more unfavorable during weekend days compared to weekdays.

CONCLUSION

In light of the SDH, consistent evidence demonstrates the structured environment of weekdays may help to protect children by regulating obesogenic behaviors, most likely through compulsory physical activity opportunities, restricting caloric intake, reducing screen time occasions, and regulating sleep schedules. Summer is emerging as the critical period where childhood obesity prevention efforts need to be focused. The SDH can help researchers understand the drivers of obesogenic behaviors during summer and lead to innovative intervention development.

Why Do Children Engage in Sedentary Behavior? Child- and Parent-Perceived Determinants

Todays children spend a large amount of their time sedentary. There is limited evidence on the determinants of sedentary behavior in children, and qualitative studies are especially lacking. Therefore, this study aimed to explore determinants of children’s sedentary behavior from the child- and parent perspective. Qualitative data were collected during concept mapping sessions with four groups of 11–13 years old children (n = 38) and two online sessions with parents (n = 21). Children and parents generated sedentary behavior motives, sorted related motives, and rated their importance in influencing children’s sedentary time. Next, multidimensional scaling and hierarchical cluster analysis was performed to create clusters of motives resulting in a concept map. Finally, the researchers named the clusters in the concept map. Concept maps of children yielded eight to ten perceived determinants, and concept maps of parents six to seven. Children and parents identified six similar potential determinants, and both rated as important: Sitting because… “it is the norm (I have to)”, and “I can work/play better that way”. In addition, children rated “there is nobody to play with” as an important potential determinant for engaging in sedentary behavior. The most important child- and parent perceived determinants were related to the social/cultural and physical environment, indicating that these are promising targets for future interventions.

Factors Associated with Screen Time in Iranian Children and Adolescents: The CASPIAN-IV Study

BACKGROUND

Prolonged screen time is frequent in children and adolescents. Implementing interventions to reduce physical inactivity needs to assess related determinants. This study aims to assess factors associated with screen time in a national sample of children and adolescents.

METHODS

This nationwide study was conducted among 14,880 students aged 6-18 years. Data collection was performed using questionnaires and physical examination. The World Health Organization-Global School Health Survey questionnaire was used. Logistic regression analysis was used to examine the relationship between demographic variables, socioeconomic status (SES), family structure, physical activity, unhealthy eating habits, body mass index, and mental distress with screen time.

RESULTS

The participation rate was 90.6% (n = 13,486), 50.8% were male, and 75.6% lived in urban areas. Mean (standard deviation) age of participants was 12.47 (3.36) years. The SES, eating junk foods, urban residence, and age had significant association with screen time, watching television (TV), and computer use (P < 0.05). With increasing number of children, the odds ratio of watching TV reduced (P < 0.001). Statistically, significant association existed between obesity and increased time spent watching TV (P < 0.001). Girls spent less likely to use computer and to have prolonged screen time (P < 0.001). Participants in the sense of worthlessness were less likely to watch TV (P = 0.005). Screen time, watching TV, and using computer were higher in students with aggressive behaviors (P < 0.001); screen time was higher in those with insomnia.

CONCLUSIONS

In this study, higher SES, unhealthy food habits, and living in urban areas, as well as aggressive behaviors and insomnia increased the risk of physical inactivity.

School grade and sex differences in domain-specific sedentary behaviors among Japanese elementary school children: a cross-sectional study

Background

It is vital to reduce the proportion of sedentary behavior in children. Understanding the duration and behavioral context is needed. The present study examined school-grade and sex differences in domain-specific sedentary times and concurrence with screen-time guidelines among Japanese elementary school children.

Methods

A total of 625 children (330 boys) were surveyed in 2010 and 2014. Using a questionnaire, data regarding participants’ grade (first through third grades: lower grades; fourth through six grades: higher grades), sex, weight, and height were collected in addition to the time spent per day engaging in each specific sedentary behavior separately: (1) reading or listening to music, (2) TV or video viewing, (3) TV game use, (4) internet use excluding class, (5) homework, and (6) car travel. Two-way analysis of covariance and logistic regression analyses, adjusted for BMI and moderate to vigorous physical activity, were used to examine school-grade and sex differences in sedentary behaviors and the independent risk of exceeding recommended total daily screen time (< 2 h).

Results

On 625 children, mean minutes (SD) of sedentary behavior per week in (1) – (6) were 90.3 (123.4), 535.0 (356.6), 167.3 (222.1), 23.9 (70.9), 264.9 (185.3), and 33.4 (61.2) in weekdays and 42.1 (70.0), 323.9 (232.0), 123.0 (96.4), 15.8 (49.9), 74.4 (96.4), and 71.3 (84.9) in weekends, respectively. There were differences in the minutes of sedentary behavior between participants of 2010 and 2014; e.g., TV game use and homework in weekdays and weekdays and car travel in weekends. Boys spent more time in TV game use, and girls spent more time reading, listening to music, doing homework, and car travel. Higher-grade students spent more time reading or listening to music, using a computer, and doing homework. Higher-grade students were 2.09 times (95% CI: 1.32 − 3.30) in whole week, 2.08 times (95% CI: 1.45 − 3.00) in weekday, and 1.88 times (95% CI: 1.29 − 2.74) in weekend more likely to spend ≥2 h per day in domains (2) − (4) (screen-time) than lower-grade students.

Conclusions

Time spent engaging in each domain-specific sedentary behavior differed according to sex and school grade. Higher-grade students were less likely to meet screen-time guidelines. These findings highlight the need for domain-focused strategies to decrease sedentary behavior in Japanese school-age children.

Socio-Ecological Variables Associated with Context-Specific Sitting Time in Belgian Older Adults: A One-Year Follow-Up Study

INTRODUCTION

Knowledge about variables associated with context-specific sitting time in older adults is limited. Therefore, this study explored cross-sectional and longitudinal associations of socio-demographic, social-cognitive, physical-environmental and health-related variables with sitting during TV viewing, computer use and motorized transport in older adults.

METHODS

A sample of Belgian older adults completed structured interviews on context-specific sitting time and associated variables using a longitudinal study design. Objective measurements of grip strength and physical performance were also completed. Complete baseline data were available of 258 participants (73.98±6.16 years) of which 229 participants remained in the study at one year follow-up (retention rate: 91.60%). Cross-sectional correlates (baseline data) and longitudinal predictors (change-scores in relation with change in sitting time) were explored through multiple linear regression analyses.

RESULTS

Per context-specific sitting time, most of the cross-sectional correlates differed from the longitudinal predictors. Increases over time in enjoyment of watching TV (+one unit), encouragement of partner to watch less TV (+one unit) and TV time of partner (+30.0 min/day) were associated with respectively 9.1 min/day (p<0.001), 16.0 min/day (p<0.001) and 12.0 min/day (p<0.001) more sitting during TV viewing at follow-up. Increases over time in enjoyment of using a computer (+one unit), the number of smartphones and tablets (+1) and computer use of the partner (+30.0 min/day) were associated with respectively 5.5 min/day (p < .01), 10.4 min/day (p < .05) and 3.0 min/day (p < .05) more sitting during computer use at follow-up. An increase over time in self-efficacy regarding taking a bicycle or walking was associated with 2.9 min/day (p < .05) less sitting during motorized transport at follow-up.

CONCLUSIONS

The results stressed the importance of looking at separate contexts of sitting. Further, the results highlighted the importance of longitudinal research in order to reveal which changes in particular variables predicted changes in context-specific sitting time. Variables at the social-cognitive level were most frequently related to context-specific sitting.

Socio-Demographic, Social-Cognitive, Health-Related and Physical Environmental Variables Associated with Context-Specific Sitting Time in Belgian Adolescents: A One-Year Follow-Up Study

INTRODUCTION

More knowledge is warranted about multilevel ecological variables associated with context-specific sitting time among adolescents. The present study explored cross-sectional and longitudinal associations of ecological domains of sedentary behaviour, including socio-demographic, social-cognitive, health-related and physical-environmental variables with sitting during TV viewing, computer use, electronic gaming and motorized transport among adolescents.

METHODS

For this longitudinal study, a sample of Belgian adolescents completed questionnaires at school on context-specific sitting time and associated ecological variables. At baseline, complete data were gathered from 513 adolescents (15.0±1.7 years). At one-year follow-up, complete data of 340 participants were available (retention rate: 66.3%). Multilevel linear regression analyses were conducted to explore cross-sectional correlates (baseline variables) and longitudinal predictors (change scores variables) of context-specific sitting time.

RESULTS

Social-cognitive correlates/predictors were most frequently associated with context-specific sitting time. Longitudinal analyses revealed that increases over time in considering it pleasant to watch TV (p < .001), in perceiving TV watching as a way to relax (p < .05), in TV time of parents/care givers (p < .01) and in TV time of siblings (p < .001) were associated with more sitting during TV viewing at follow-up. Increases over time in considering it pleasant to use a computer in leisure time (p < .01) and in the computer time of siblings (p < .001) were associated with more sitting during computer use at follow-up. None of the changes in potential predictors were significantly related to changes in sitting during motorized transport or during electronic gaming.

CONCLUSIONS

Future intervention studies aiming to decrease TV viewing and computer use should acknowledge the importance of the behaviour of siblings and the pleasure adolescents experience during these screen-related behaviours. In addition, more time parents or care givers spent sitting may lead to more sitting during TV viewing of the adolescents, so that a family-based approach may be preferable for interventions. Experimental study designs are warranted to confirm the present findings.

Joint association of screen time and physical activity on self-rated health and life satisfaction in children and adolescents: the CASPIAN-IV study

BACKGROUND

Self-rated health and life satisfaction are two subjective measures for assessing overall health status. This study aims to investigate the association of self-rated health and life satisfaction with physical activity and screen time.

METHODS

As part of the fourth survey of a national surveillance program in Iran (CASPIAN-IV study), 14 880 students aged 6 to 18 years were selected via multi-stage cluster sampling from 30 provinces. Data were obtained from the WHO Global School-Based Student Health Survey questionnaire.

RESULTS

A total of 13 486 students with mean age of 12.47 (SD 3.36) completed the study. In crude model both prolonged screen time and physical activity were associated with favorable life satisfaction and self-rated health. However, in multivariate analysis only high physical activity was associated with good self-rated health (OR 1.37) and life satisfaction (OR 1.39), while prolonged screen time was not associated with good self-rated health (OR 1.02) and life satisfaction (OR 0.94). For combined screen time-physical activity variable, low screen time-high physical activity combination had the highest OR for both good self-rated health (OR 1.37) and life satisfaction (OR 1.43) in multivariate analysis.

CONCLUSIONS

Our findings suggest that increasing physical activity is more crucial than emphasizing reducing screen time in improving the well-being of children and adolescents.

The mediating role of energy intake on the relationship between screen time behaviour and body mass index in adolescents with obesity: The HEARTY study

Adolescents spend up to 6-8 h/day in sedentary screen behaviour and screen time is an independent risk factor for obesity. However, the mechanisms by which screen time confers obesity risk remain unclear. Via community level recruitment this study examined whether the relationship between screen time behaviours and body mass index (BMI: kg/m²) was mediated by total energy intake or macronutrient consumption. In a cross-sectional study of post-pubertal adolescents (N = 283: 86M, 197F) with overweight or obesity at baseline of an intervention for weight control, we examined self-reported total energy intake (mean Calories from 3 day food diary), macronutrient intake (grams/day of carbohydrate, fat, protein) and total screen time (aggregate of hours/day watching TV, playing seated video games, and recreational computer use). BMI was objectively measured and converted to standardized scores (z-BMI). Simple and multiple mediation analyses were conducted using the bootstrapping approach described by Preacher and Hayes. Covariates included age, sex, ethnicity, parental education, Tanner stage, and self-reported physical activity. The relationship between screen time and z-BMI was significantly mediated by energy intake. Higher levels of carbohydrate intake, but not fat or protein intake, significantly mediated the relationship between screen time and z-BMI (95% bias-corrected and accelerated confidence interval [0.0004, 0.0074]). Higher carbohydrate intake mediated the relationship between TV viewing and z-BMI, and video gaming and z-BMI. In conclusion, the relationship between screen time and BMI appears to be mediated by increased energy intake, primarily in the form of higher carbohydrate intake. It is possible that reducing time spent watching TV and playing video games may reduce food intake and help promote dietary adherence needed for weight management in obese adolescents.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT00195858.

International Trends in Adolescent Screen-Time Behaviors From 2002 to 2010

PURPOSE

Engaging in prolonged screen-time behaviors (STBs) is detrimental for health. The objective of the present analyses was to examine temporal trends in TV viewing and computer use among adolescents across 30 countries.

METHODS

Data were derived from the cross-national Health Behaviour in School-aged Children study. Data on TV viewing and computer use for gaming and nongaming purposes were collected in 2002 (n = 139,725 [51.4% girls]), 2006 (n = 149,251 [51.3% girls]), and 2010 (n = 154,845 [51.2% girls]). The temporal trends in TV viewing and computer use were each tested for all countries combined and for each individual country by sex-specific univariate analysis of variance.

RESULTS

Between 2002 and 2010, TV viewing decreased slightly in most of the 30 countries among both boys and girls. This decrease was more than offset by a sharp increase in computer use, which was consistent across all countries. Overall, boys reported more hours of STBs. They also reported a slightly larger decrease in TV viewing and slightly larger increase in computer use. STBs were generally more frequent on weekend days.

CONCLUSIONS

The overall cross-national increases in STBs should be a call to action for public health practitioners, policy-makers, and researchers that interventions specifically focused on reducing STBs in youth are sorely needed. Because all countries experienced a trend in the same direction, it might be fruitful to learn more about the determinants of STBs among those countries in which hours of STBs are generally low as compared with other countries.

Intrapersonal, social-cognitive and physical environmental variables related to context-specific sitting time in adults: a one-year follow-up study

Background

Investigating associations between socio-ecological variables and context-specific sitting time in adults can support the development of future interventions. The purpose of the present study was to examine the cross-sectional and longitudinal relationships of intrapersonal, social-cognitive and physical environmental variables with context-specific sitting time (i.e. TV-viewing, computer use, motorized transport, and occupational sitting) in adults.

Methods

In this longitudinal study, data were retrieved from a random sample of Flemish (Belgian) adults. At baseline, 301 adults (age, 43.3 ± 10.6 years) completed a questionnaire on context-specific sitting time and its potential predictors. After a 1-year follow-up period, complete data of 188 adults was available (age, 46.0 ± 10.4 years). Multiple linear regression analyses were performed for both the cross-sectional data at baseline (correlates) and the longitudinal data (predictors).

Results

The cross-sectional and longitudinal analyses revealed different relationships between sitting during TV viewing, computer use, motorized transport and occupation. Generally, change in cross-sectional correlates did not cause change in context-specific sitting time in the longitudinal analyses. Social-cognitive correlates/predictors were most frequently identified, followed by intrapersonal correlates/predictors. Attitude, self-efficacy, (social) norm and modelling were found to be the most consistently related social-cognitive correlates/predictors to context-specific sitting time. Limited evidence was available for relationships between physical environmental variables and context-specific sitting time.

Conclusions

The cross-sectional correlates differed from the longitudinal predictors of context-specific sitting time, highlighting the need for longitudinal research. The present study also underlined the need for family interventions to minimize context-specific sitting time, as both intrapersonal and social-cognitive variables were associated with context-specific sitting time.

Higher screen time is associated with overweight, poor dietary habits and physical inactivity in Brazilian adolescents, mainly among girls

OBJECTIVES

To analyse the associations between high screen time and overweight, poor dietary habits and physical activity in adolescents according to sex.

METHODS

The study comprised 515 boys and 716 girls aged 14-17 years from Londrina, Brazil. Nutritional status (normal weight or overweight/obese) was assessed by calculating the body mass index. Eating habits and time spent in physical activity were reported using a questionnaire. The measurement of screen time considered the time spent watching television, using a computer and playing video games during a normal week. Associations between high screen time and dependent variables (nutritional status, eating habits and physical activity levels) were assessed by binary logistic regression, adjusted for sociodemographic and lifestyle variables.

RESULTS

Most adolescents (93.8% of boys and 87.2% of girls) spent more than 2 hours per day in screen-time activities. After adjustments, an increasing trend in the prevalence of overweight and physical inactivity with increasing time spent on screen activities was observed for both sexes. Screen times of >4 hours/day compared with <2 hours/day were associated with physical inactivity, low consumption of vegetables and high consumption of sweets only in girls and the consumption of soft drinks in both sexes.

CONCLUSIONS

The frequency of overweight and physical inactivity increased with increasing screen time in a trending manner and independently of the main confounders. The relationship between high screen time and poor eating habits was particularly relevant for adolescent girls.