Is spending time in screen-based sedentary behaviors associated with less physical activity: a cross national investigation

Stability and bidirectional relationship between physical activity and sedentary behaviours in Brazilian adolescents: Longitudinal findings from a school cohort study

Purpose

We investigated the stability, correlations and bidirectional relationship of light physical activities (PA), moderate and vigorous PA (MVPA), television viewing (TV) and video game/computer use (VG) in Brazilian adolescents.

Methods

Adolescent Nutritional Assessment Longitudinal Study-ELANA is a middle school cohort study conducted in Rio de Janeiro-Brazil in 2010–2012. Self-reported data on PA (International Physical Activity Questionnaire- IPAQ) and screen activities were obtained from 810 adolescents (mean ages of 10.9 years old (SD 0.78) for girls; 11 years old (SD 0.85) for boys) to perform autoregressive cross-lagged structural equation models in two time points for PA and three time points for screen activities.

Results

There was no significant stability of light PA and MVPA for boys and girls. Moderate stability of screen activities were found for both genders, with a significant coefficient of TV for boys (T1-T2:0.29; T2-T3:0.27 p<0.001); and VG for boys (T1-T2:0.33; T2-T3:0.35 p<0.001) and girls (T1-T2: 0.26; T2-T3:0.37 p<0.01). Significant lagged effects were obtained only among girls: light PA had effect on VG (-0.10 p<0.01), as well as in the opposite direction of TV on light PA (-0.03 p<0.01) and TV on MVPA (-0.11 p<0.01).

Conclusion

The light PA, MVPA and screen activities (among girls) did not demonstrate stability over time. A warning scenario was suggested by the stability of high amounts of screen activities among boys over time. Screen activities had bidirectional association with light PA and MVPA among girls over time.

Comparisons in Screen-Time Behaviours among Adolescents with and without Long-Term Illnesses or Disabilities: Results from 2013/14 HBSC Study

Reducing sedentary behaviours can help prevent non-communicable diseases, particularly among young adolescents with long term illnesses or disabilities (LTID). Much of young people’s voluntary sedentary time is related to screen-time behaviours (STBs) such as TV viewing, playing computer games, and using the computer for other activities. Although public health data on adolescents’ STB is growing, information about adolescents with LTID is currently lacking in a European context. The purpose of this study is to compare time on STBs between adolescents with and without LTID in European Countries through the HBSC 2013/14 study. Young adolescents (n = 61,329; boys 47.8%) from 15 European countries reported the time spent on TV viewing, playing computer games, and using the computer for other purposes on weekdays and the weekend. STBs were dichotomised based on international recommendations of less than 2 h per day, and Chi-square tests of independence were performed to investigate differences. STB time was combined to produce a sum score as dependent variable in multiple analysis of covariance with age and family affluence as covariates. There were statistically significant differences in computer gaming among boys and other computer use among girls for both weekdays and weekends, whereby adolescents with LTID reported higher use. In addition, both boys and girls with LTID spent more time on STBs than their same sex peers without LTID (Boys, F = 28.17, p < 0.001; Girls, F = 9.60, p = 0.002). The results of this study indicate a need for preventive strategies to address high levels of STB among young adolescents with LTID and reduce the risk of poor health outcomes associated with higher levels of sedentary behaviour.

Intention and automaticity toward physical and sedentary screen-based leisure activities in adolescents: A profile perspective

PURPOSE

Physical activity (PA) and sedentary behavior (SB) are increasingly considered independent health behaviors. Additionally, current research suggests that both controlled and automatic determinants account for their adoption. The purpose of this article was to identify intention-automaticity profiles toward PA and screen-based SB and to examine how those profiles are associated with different behavioral patterns.

METHOD

Two cross-sectional studies based on self-report questionnaires were conducted with French high school students (Study 1: n = 198; Study 2: n = 185).

RESULTS

In all, 4 distinct motivational profiles appeared. The first 3 clusters emerged in both studies: "PA" (high levels of automaticity and intention for PA, low levels of automaticity and intention for screen-based SB); "screen" (high levels of automaticity and intention for screen-based SB, low levels of automaticity and intention for PA), and "mixed" (high levels of all variables), whereas the fourth cluster was observed only in Study 2: "high control" (below-mean levels of automaticity, high levels of intention toward both PA and screen-based SB). Adolescents with a screen profile displayed the least healthy behavioral pattern, whereas those in the PA profile demonstrated the most favorable behaviors.

CONCLUSION

Future research is needed to extend these results to other populations using complementary assessment methods of automatic psychological processes and PA and SB behaviors.

Tracking of Physical Activity, Sport Participation, and Sedentary Behaviors over Four Years of High School

Background: The aim of the present study was to investigate the extent of tracking of physical activity (PA), sports participation (SP), and sedentary behaviors (SB) over four years of high school education among the Croatian Physical Activity in Adolescence Longitudinal Study (CRO-PALS) cohort. Methods: In this investigation, participants were 844 high school students (15.6 years at baseline; 49% girls). The SHAPES questionnaire was used to assess PA, SP, and SB at ages 15, 16, 17, and 18 and tracking was assessed using generalized estimating equations. Results: Tracking coefficients for PA were similar in both sexes, ranged from 0.49 to 0.61, and indicated moderate tracking, while the tracking of SB tended to be somewhat higher over the four years of follow-up (β = 0.60–0.72). Youth that participated in sports at baseline had a 16 to 28 times higher odds of continued participation at follow-up, depending on the type of sport and gender. Finally, both low physical activity and high screen time showed strong tracking in both genders. Conclusion: PA and SB tracked moderately between ages 15 and 18. Moreover, the strong tracking of low PA and high screen time indicates that the detection of these risk factors at the beginning of high school should be advocated.

Towards a demographic risk profile for sedentary behaviours in middle-aged British adults: a cross-sectional population study

OBJECTIVES

In response to a call from the American Heart Association to more clearly identify the demographic factors associated with sedentary behaviours, this study aimed to identify the hierarchy of demographic characteristics associated with the sedentary behaviours of television viewing, recreational computer use and driving.

DESIGN

Cross-sectional analysis of baseline data collected as part of the UK Biobank. The UK Biobank is a population cohort recruited from 22 centres across the UK. Participants aged between 37 and 73 years were recruited between 2006 and 2010.

METHODS

Decision tree models were generated for the sedentary behaviour outcomes of hours/day spent television viewing, recreational computer use and all driving; a sum of time spent in these sedentary behaviours ('overall') was computed. Age, sex, race, college attendance, employment, shift-work, urban versus rural residence as well as physical activity were considered as predictors.

RESULTS

The analytic sample comprised 415 666 adults who were mostly female (54.2%), white (95.2%), non-college attendee (64.5%), employed (61.7%), lived in an urban centre (85.5%), with a mean age of 56.6 (SD=8.1) years. Television viewing was most common sedentary behaviour (2.7 hour/day vs 1.1 for recreational computer use and 1.0 for all driving). Males (tier 1), who did not attend college (tier 2) were the highest risk group for overall sedentary time. Adults with no college attendance (tier 1) and were retired (tier 2) were the most high-risk demographic group for television viewing. College attendees (tier 1) were highest risk for recreational computer use. Adults who were employed (tier 1), male (tier 2) and did not attend college (tier 3) were most at risk for driving CONCLUSIONS: Daily time spent in different sedentary behaviours varies by sex, employment status and college attendance status. The development of targeted interventions to reduce sedentary behaviour in different demographic subgroups is needed.

Cross-sectional and prospective associations between sleep, screen time, active school travel, sports/exercise participation and physical activity in children and adolescents

BACKGROUND

The aim of this study was to investigate how sleep, screen time, active school travel and sport and/or exercise participation associates with moderate-to-vigorous physical activity (MVPA) in nationally representative samples of Norwegian 9- and 15-y-olds, and whether these four behaviors at age nine predict change in MVPA from age nine to 15 years.

METHOD

We pooled cross-sectional accelerometer and questionnaire data from 9- (n = 2366) and 15-y-olds (n = 1554) that participated in the first (2005/06) and second (2011/12) wave of the Physical Activity among Norwegian Children Study to investigate cross-sectional associations. To investigate prospective associations, we used data from a sub-sample that participated in both waves (at age nine and 15 years, n = 517).

RESULTS

Cross-sectional analyses indicated a modest, inverse association between screen time and MVPA among 9- (- 2.2 min/d (95% CI: -3.1, - 1.3)) and 15-y-olds (- 1.7 min/d (95% CI: -2.7, - 0.8)). Compared to their peers with 0-5 min/d of active travel to school, 9- and 15-y-olds with ≥16 min/d accumulated 7.2 (95% CI: 4.0, 10.4) and 9.0 (95% CI: 3.8, 14.1) more min/d of MVPA, respectively. Nine-y-old boys and 15-y-olds reporting ≥8 h/week of sports and/or exercise participation accumulated 14.7 (95% CI: 8.2, 21.3) and 17.9 (95% CI: 14.0, 21.8) more min/d of MVPA, respectively, than those reporting ≤2 h/week. We found no cross-sectional association between sleep duration and MVPA in either age group. None of the four behaviors predicted change in MVPA from age nine to 15 years (p ≥ 0.102).

CONCLUSION

Active travel to school and sport/exercise participation may be important targets for future interventions aimed at increasing MVPA in children and adolescents. However, future studies are needed to determine causality.

Physical Activity, a Critical Exposure Factor of Environmental Pollution in Children and Adolescents Health Risk Assessment

It is an extremely urgent problem that physical fitness promotion must face not only the increasing air pollution but also the decline of physical activity level of children and adolescents worldwide at present, which is the major reason that forms an inactive lifestyle and does harm to adolescents’ health. Thus, it is necessary to focus on the exposure factor in environmental health risk assessment (EHRA) which conducts supervision of environmental pollution and survey of adolescents’ activity patterns according to the harmful characteristics of air pollutant and relationship between dose and response. Some countries, such as USA, Canada and Australia, regard both respiratory rate and physical activity pattern as main exposure factors for adolescents in both air pollution health risk assessment and exercise risk assessment to forecast a safe exposing condition of pollutant for adolescents while they are doing exercise outdoors. In addition, it suggests that the testing indexes and testing methods of these two exposure factors, such as investigating the time of daily physical activity, strength, and characteristic of frequency, help to set up the quantitative relationship between environmental pollution index and the time, strength, frequency of daily activities, and formulate children’s and adolescents’ activity instructions under different levels of environmental pollutions. As smog becomes increasingly serious at present, it is meaningful to take physical activity as a critical composition of exposure factor and establish physical activity guideline, so as to reduce the risk of air pollution, and promote physical health of children and adolescents effectively.

Association between lifestyle factors and suboptimal health status among Chinese college freshmen: a cross-sectional study

Background

Suboptimal health status (SHS) is the third state between good health and disease. SHS is the clinical or pre-disease status of psychosomatic disease and a major global public health challenge. Although its underlying causes remain unclear, lifestyle is one of the most important factors affecting health status.

Methods

A cross-sectional survey was conducted at Renmin University of China in September of 2015. Data were collected from college freshmen using a questionnaire covering characteristics, lifestyle, nutrition status, and health status. A total of 6025 questionnaires were distributed during the study period, and 5344 completed responses were received.

Results

The prevalence rates for the “healthy,” “SHS,” and “disease” groups of college freshmen were 46.7% (2433), 51.2% (2667), and 2.1% (111), respectively. It is notable that health status was significantly positively correlated with lifestyle (Spearman’s r = 0.4435, p < 0.001). The multivariate Logistic regression results showed that students who were relatively younger and students from rural areas had a higher percentage of SHS. Good sleep quality (aOR = 0.650, 95%CI = 0.612–0.690), abundant physical exercise (aOR = 0.889, 95%CI = 0.845–0.933), and adequate nutrition intake (aOR = 0.868, 95%CI = 0.864–0.908) are negatively associated with SHS. Overuse of electronic devices (aOR = 1.066, 95%CI = 1.013–1.121), smoking (aOR = 1.824, 95%CI = 1.195–2.755), and weight loss (aOR = 1.255, 95%CI = 1.043–1.509) are positively associated with SHS.

Conclusions

Poor lifestyle behaviors are associated with SHS. In particular, the overuse of electronic devices is one of underlying causes of SHS. By altering lifestyle behaviors for the better, the health statuses of these college freshmen can be effectively improved.

Electronic supplementary material

The online version of this article (10.1186/s12889-017-5002-4) contains supplementary material, which is available to authorized users.

Head, trunk and arm posture amplitude and variation, muscle activity, sedentariness and physical activity of 3 to 5 year-old children during tablet computer use compared to television watching and toy play

Young children (ages 3 to 5) are using mobile touchscreen technology, including tablet computers, yet little is known on the potential musculoskeletal and physical activity implications of its use. This within-subject laboratory study (n = 10) examined head, trunk and arm postures, upper trapezius muscle activity, and total body and upper limb physical activity during playing with tablets compared to during TV watching and playing with non-screen toys. Overall, this study found that during tablet play children had greater mean head, trunk and upper arm angles compared to both TV watching and toy play. Conversely, compared to toy play, children playing with tablets had lesser trunk, upper arm and elbow postural variation, lesser trapezius activity, more time sitting and lesser physical activity. Thus, to minimize potential musculoskeletal and sedentary risks, non-screen toy play should be encouraged and education and guidelines provided for parents and caretakers to support wise use of tablets.

Joint association of screen time and physical activity with anthropometric measures in Iranian children and adolescents: the weight disorders survey of the CASPIAN-IV study

BACKGROUND

This study aims to assess the joint association of screen time (ST) and physical activity (PA) with anthropometric indices among Iranian children and adolescents.

METHODS

In this national study, 23,183 school students, aged 6-18 years, were studied. By using a multi-stage cluster sampling method, they were selected from rural and urban areas of 30 provinces of Iran. ST and PA were assessed by self-administered validated questionnaires. Height, weight, hip and waist circumferences (WC) were measured according to standard protocols, and body mass index (BMI) was calculated. ST of <2 h per day was categorized as "low" and ≥2 h per day as "high". PA levels were obtained by a 7-day recall of sports or activities that made participants sweat or make their legs feel tired, or games that made them breathe heavily. Using this questionnaire, the score of 1-1.9 was categorized as "low" and scores between 2 and 5 as "high" PA. Logistic regression analyses were used to evaluate the joint association of PA and ST categories with odds of anthropometric measures.

RESULTS

In both genders, those students categorized as "Low PA & High ST" had the highest levels of BMI z-scores (boys: 0.15±1.12, girls: 0.17±1.08), WC (boys: 69.93±13.89 cm, girls: 67.30±11.26 cm), and hip circumference (boys: 82.41±13.90 cm, girls: 84.05±13.7 cm), as well as the highest prevalence of overweight (boys: 15.32%, girls: 14.04%) (p<0.001 in all comparisons). In linear multivariate model, students with "High PA & High ST" had significant increased levels of z-scores for BMI, WC and hip circumference (p<0.05).

CONCLUSIONS

The current findings underscore the importance of reducing ST along with increasing PA for prevention and control of excess weight in children and adolescents.

Standing Classrooms: Research and Lessons Learned from Around the World

Children spend between 50 and 70 % of their time sitting while at school. Independent of physical activity levels, prolonged sitting is associated with poor health outcomes in adulthood. While there is mixed evidence of health associations among children and adolescents, public health guidelines in the USA, UK, Australia and Canada now recommend young people should break up long periods of sitting as frequently as possible. A potentially effective approach for reducing and breaking up sitting throughout the day is changing the classroom environment. This paper presents an overview of a relatively new area of research designed to reduce youth sitting time while at school by changing the classroom environment (n = 13 studies). Environmental changes included placement of height-adjustable or stand-biased standing desks/workstations with stools, chairs, exercise balls, bean bags or mats in the classroom. These 13 published studies suggest that irrespective of the approach, youth sitting time was reduced by between ~44 and 60 min/day and standing time was increased by between 18 and 55 min/day during classroom time at school. Other benefits include increased energy expenditure and the potential for improved management of students' behaviour in the classroom. However, few large trials have been conducted, and there remains little evidence regarding the impact on children's learning and academic achievement. Nevertheless, with an increasing demand placed on schools and teachers regarding students' learning outcomes, strategies that integrate moving throughout the school day and that potentially enhance the learning experience and future health outcomes for young people warrant further exploration.

Effectiveness of interventions on physical activity in overweight or obese children: a systematic review and meta-analysis including studies with objectively measured outcomes

There is no consensus on interventions to be recommended in order to promote physical activity among overweight or obese children. The objective of this review was to assess the effects on objectively measured physical activity, of interventions promoting physical activity among overweight or obese children or adolescents, compared to no intervention or to interventions without a physical activity component. Publications up to December 2015 were located through electronic searches for randomized controlled trials resulting in inclusion of 33 studies. Standardized mean differences from baseline to post-intervention and to long-term follow-up were determined for intervention and control groups and meta-analysed using random effects models. The meta-analysis showed that interventions had no effect on total physical activity of overweight and obese children, neither directly post-intervention (-0.02 [-0.15, 0.11]) nor at long-term follow-up (0.07 [-0.27, 0.40]). Separate analyses by typology of intervention (with or without physical fitness, behavioural or environmental components) showed similar results (no effect). In conclusion, there is no evidence that currently available interventions are able to increase physical activity among overweight or obese children. This questions the contribution of physical activity to the treatment of overweight and obesity in children in the studied interventions and calls for other treatment strategies.

Attention-Deficit/Hyperactivity Disorder and Lifestyle-Related Behaviors in Children

Attention-deficit/hyperactivity disorder (ADHD) has been associated with obesity in children. Lifestyle-related behaviors (external eating, screen time and physical inactivity) are well known to be associated with increased risk of obesity, but their associations with ADHD are unclear. The objectives of this study were to clarify the associations between ADHD symptoms in children and their associated lifestyle. A cross sectional study was carried out with a total of 785 primary students aged 9 to 13 years old and their parents were recruited by stratified random sampling from primary schools of China. The Cochran-Mantel-Haenszel (CMH) test was used to examine the relationships between ADHD symptoms and health related behaviors. We found that children with ADHD symptoms were likely to spend more time using a computer during school days; they were also more likely to eat while using a computer. These children were also more likely to eat while seated in a car, using a smart phone, using a computer at bedtime, and snacking before going to sleep than children without ADHD symptoms. An increased risk of obesity in children with ADHD symptoms was associated with the overuse of electronic devices, eating while using electronic devices, and delaying bedtimes to snack and use electronic devices.

The effectiveness of sedentary behaviour interventions for reducing body mass index in children and adolescents: systematic review and meta-analysis

Intervention studies have been undertaken to reduce sedentary behaviour (SB) and thereby potentially ameliorate unhealthy weight gain in children and adolescents. We synthesised evidence and quantified the effects of SB interventions (single or multiple components) on body mass index (BMI) or BMI z-score in this population. Publications up to March 2015 were located through electronic searches. Inclusion criteria were interventions targeting SB in children that had a control group and objective measures of weight and height. Mean change in BMI or BMI z-score from baseline to post-intervention were quantified for intervention and control groups and meta-analyzed using a random effects model. The pooled mean reduction in BMI and BMI z-score was significant but very small (standardized mean difference = -0.060, 95% confidence interval: -0.098 to -0.022). However, the pooled estimate was substantially greater for an overweight or obese population (standardized mean difference = -0.255, 95% confidence interval: -0.400 to -0.109). Multicomponent interventions (SB and other behaviours) delivered to children from 5 to 12 years old in a non-educational setting appear to favour BMI reduction. In summary, SB interventions are associated with very small improvement in BMI in mixed-weight populations. However, SB interventions should be part of multicomponent interventions for treating obese children. © 2016 World Obesity.

Adolescent BMI trajectories with clusters of physical activity and sedentary behaviour: an exploratory analysis

Objective

The purpose of this study is to identify distinct body mass index (BMI) trajectories associated with weight classification, and to examine demographic characteristics and clusters of obesogenic behaviours in adolescents with these trajectories.

Methods

Data were extracted from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (n = 1,006, Grades 5–8). The independent variables were physical activity (accelerometer and child report), sports participation, television/video watching time and recreational computer use. The dependent variable was raw BMI. Growth mixture modelling, mixture modelling and independent t‐test analyses were used.

Results

Two distinct BMI trajectories were identified – one with the mean BMI within the Overweight–Obese classification (≥85^th percentile) and the other within the healthy weight classification (5^th– 84^th percentile). Two clusters of physical and sedentary behaviours were identified in adolescents with the Overweight–Obese BMI trajectory. These clusters differed in the type of sedentary behaviour (computer vs. television/video). Three clusters were identified in adolescents with the Healthy Weight BMI trajectory. These clusters differed in levels of physical activity and types of sedentary behaviour.

Conclusion

This study contributes to the understanding of multi‐dimensional obesogenic behavioural patterns and highlights the importance of understanding types of sedentary behaviour in adolescents.

Age and Gender Differences in Prevalence of Screen Based Behaviour, Physical Activity and Health Complaints among Slovak School-aged Children

AIM

The aim of this study was to assess age and gender differences in prevalence of screen based behaviour, physical activity and health complaints among Slovak school-aged children.

METHODS

Data from the cross-sectional Health Behaviour of School-aged Children study collected in 2010 among Slovak children (age 11-15 years, N=8,042) was used. Logistic regression models adjusted to age and gender were used to analyse the associations between watching TV, working with a computer or playing computer games and physical activity and headache, backache, sleep difficulties, feeling low, irritability, and feeling nervous.

RESULTS

Around one-quarter of adolescents is spending more than three hours a day with screen-based activities. While the age was significantly associated with watching TV and computer use, gender was significantly associated only with excessive computer use. As for physical activity only 25% of adolescents reported being physically active every day as recommended, and this number decreases with increasing age. Boys used to be more often active in comparison with girls. A sizeable number of adolescents suffer with selected health complaints every week. Moreover, the prevalence of health complaints increases with age and is significantly higher among girls.

CONCLUSIONS

The prevalence of screen-based activities as well as insufficient physical activity and health complaints among adolescents is relatively high and it increases with age. Gender differences are also significant, except for watching TV.

Sedentary behavior in Brazilian children and adolescents: a systematic review

OBJECTIVE

To describe the methodological characteristics of the studies selected and assess variables associated with sedentary behavior in Brazilian children and adolescents.

METHODS

For this systematic review, we searched four electronic databases: PubMed, Web of Knowledge, LILACS, SciELO. Also, electronic searches were applied in Google Scholar. A supplementary search was conducted in the references lists of the included articles and in non-indexed journals. We included observational studies with children and adolescents aged from three to 19 years developed in Brazil, presenting analyses of associations based on regression methods and published until September 30, 2014.

RESULTS

Of the 255 potential references retrieved by the searches, 49 met the inclusion criteria and composed the descriptive synthesis. In this set, we identified a great number of cross-sectional studies (n = 43; 88.0%) and high methodological variability on the types of sedentary behavior assessed, measurement tools and cut-off points used. The variables most often associated with sedentary behavior were "high levels of body weight" (in 15 out of 27 studies; 55.0%) and "lower level of physical activity" (in eight out of 16 studies; 50.0%).

CONCLUSIONS

The findings of this review raise the following demands to the Brazilian agenda of sedentary behavior research geared to children and adolescents: development of longitudinal studies, validation of measuring tools, establishment of risk cut-offs, measurement of sedentary behavior beyond screen time and use of objective measures in addition to questionnaires. In the articles available, the associations between sedentary behavior with "high levels of body weight" and "low levels of physical activity" were observed in different regions of Brazil.

Screen-based behaviour in school-aged children with long-term illness

Background

Evidence is lacking on the screen-based behaviour of adolescents with a chronic condition. The aim of our study was to analyse differences in screen-based behaviour of adolescents by long-term illness, asthma and learning disabilities.

Methods

We used data from the cross-sectional Health Behaviour of School-aged Children study collected in 2014 among Slovak adolescents (age 13 to 15 years old, N = 2682, 49.7 % boys). We analysed the associations between screen-based behaviour and long-term illness, asthma and learning disabilities using logistic regression models adjusted for gender.

Results

We found no associations between screen-based behaviour and long-term illness, except that children with asthma had a 1.60-times higher odds of excessively playing computer games than healthy children (95 % confidence interval of odds ratio (CI): 1.11–2.30). Children with learning disabilities had 1.71-times higher odds of risky use of the Internet (95 % CI: 1.19–2.45).

Conclusion

Adolescents with a long-term illness or with a chronic condition or a learning disability do not differ from their peers in screen-based activities. Exceptions are children with asthma and children with learning disabilities, who reported more risky screen-based behaviour.

Sedentary Behaviors by Type of Day and Physical Activity in Spanish Adolescents: A Socio-Ecological Approach

The aim of this study was to analyze the relationship between TV and computer use, study time, and physical activity, with regard to gender, school, and weekday/weekend. Adolescents (N = 1,609; M age = 14.5 yr., SD = 1.3) reported on physical activity, sedentary behavior, their parents' employment, and environmental factors. The relationship between PA and screen media behaviors was negative on weekdays, while no relationship was found at weekends. Only 30.7% of adolescents met the screen media guidelines on weekdays and 14.6% at weekends. Girls spent more time on study, only showing a positive relationship with physical activity on weekdays. Each type of sedentary behavior has different correlates for weekdays and weekends.

Risk for exercise dependence, eating disorder pathology, alcohol use disorder and addictive behaviors among clients of fitness centers

BACKGROUND AND AIMS

Exercise dependence (EXD) is considered a behavioral addiction that is often associated with eating disorders. To date, only few studies examined the potential overlap between EXD and other addictive behaviors. Therefore, the present study aimed at investigating the relationship of EXD with pathological buying, pathological video gaming (offline and online), hypersexual behavior, and alcohol use disorder in a sample of clients of fitness centers.

METHODS

The following questionnaires were answered by 128 individuals (age M = 26.5, SD = 6.7 years; 71.7% men, 74.2% university students): Exercise Dependence Scale, Eating Disorder Examination-Questionnaire, Compulsive Buying Scale, Pathological Computer-Gaming Scale, Hypersexual Behavior Inventory, and Alcohol Use Disorders Identification Test (AUDIT).

RESULTS

7.8% of the sample were at-risk for EXD, 10.9% reported eating disorder pathology, 2.3% pathological buying, 3.1% hypersexual behavior, and none of the participants suffered from pathological video gaming. The criteria for severe alcohol disorder pathology (AUDIT ≥ 16) were fulfilled by 10.2%. With regard to continuous symptom scores, EXD symptoms were positively correlated with both eating disorder pathology and pathological buying but not with pathological video gaming, hypersexuality or alcohol use disorder. It is noteworthy that more symptoms of pathological buying corresponded with more symptoms of hypersexual behavior. The correlation pattern did not differ by gender.

DISCUSSION

The co-occurrence of EXD, pathological buying and hypersexual behavior on a subclinical level or in the early stage of the disorders should be taken into account when assessing and treating patients. More research is warranted in order to investigate possible interactions between these conditions.

Association between electronic equipment in the bedroom and sedentary lifestyle, physical activity, and body mass index of children

OBJECTIVE

To describe the association between electronic devices in the bedroom with sedentary time and physical activity, both assessed by accelerometry, in addition to body mass index in children from São Caetano do Sul.

METHODS

The sample consisted of 441 children. The presence of electronic equipment (television, personal computer, and videogames) in the bedroom was assessed by a questionnaire. For seven consecutive days, children used an accelerometer to objectively monitor the sedentary time and moderate-to-vigorous physical activity. Body mass index was categorized as suggested by the World Health Organization.

RESULTS

Overall, 73.9%, 54.2% and 42.8% of children had TV, computer, and videogames in the bedroom, respectively, and spent an average of 500.7 and 59.1 min/day of sedentary time and moderate-to-vigorous physical activity. Of the children, 45.3% were overweight/obese. Girls with a computer in the bedroom (45 min/day) performed less moderate-to-vigorous physical activity than those without it (51.4 min/day). Similar results were observed for body mass index in boys. Moderate-to-vigorous physical activity was higher and body mass index was lower in children that had no electronic equipment in the bedroom. Presence of a computer (β=-4.798) and the combination TV+computer (β=-3.233) were negatively associated with moderate-to-vigorous physical activity. Videogames and the combinations with two or three electronic devices were positively associated with body mass index. Sedentary time was not associated with electronic equipment.

CONCLUSION

Electronic equipment in the children's bedroom can negatively affect moderate-to-vigorous physical activity and body mass index regardless of gender, school, and annual family income, which can contribute to physical inactivity and childhood obesity.

Condições de vida, inatividade física e conduta sedentária de jovens nas áreas urbana e rural

RESUMO Introdução: Poucas evidências destacam aspectos das condições de vida em adolescentes residentes nas áreas urbana e rural. Objetivo: Verificar indicadores das condições de vida associados às prevalências do nível de atividade física abaixo das recomendações (NAFAR) e da exposição ao comportamento sedentário (ECS) em escolares de áreas urbanas e rurais de Sergipe, Brasil. Métodos: Realizou-se um estudo transversal de base escolar. Compuseram a amostra 3.992 escolares, com idade variando de 14 a 19 anos. Resultados: A prevalência de adolescentes com NAFAR foi de 77,5% (urbana 76%; rural 80%) e ECS de 46,7 % (urbana 50,2%; rural 41,2%). Em áreas urbanas, verificou-se a associação da ECS com o território, período de estudo, escolaridade materna, situação ocupacional do adolescente e renda familiar. O NAFAR associou-se com o fato de residir com o pai e com o trabalho do pai. Em áreas rurais, a ECS associou-se ao período de estudo, situação ocupacional do adolescente e a renda familiar. O NAFAR associou-se à situação ocupacional do adolescente. Conclusão: Os resultados mostraram que o NAFAR e a ECS estiveram relacionados a diferentes indicadores de condições de vida, sugerindo intervenções variadas considerando o local de residência.

Physical activity among adolescents: The role of various kinds of parental support

The objectives of this study were (a) to examine the association between various kinds of parental social support and adolescents' physical activity (PA) and (b) to examine whether various kinds of social support from mothers and fathers were differently associated with boys' and girls' PA. Data came from the Aarhus School Survey that included 2100 schoolchildren at 11, 13, and 15 years of age. Parental social support for PA was measured by items about encouragement to do PA, doing joint PA, parents watching PA, and talking about PA. PA was measured as at least 4 h of vigorous PA per week during leisure time. We used logistic regression analyses to estimate the associations for girls and boys separately, adjusted by age group, parents' occupational social class, family structure, and migration status. There were significant and graded associations between adolescents' PA and all four dimensions of parental support for PA. The association patterns were similar for mothers' and fathers' social support and similar for girls and boys. Social processes in the family are important for adolescents' participation in PA. It is important to continue to explore these social processes in order to understand why some adolescents are physically active and others are not.

The relation between internet use and overweight among adolescents: a longitudinal study in Switzerland

OBJECTIVE

This longitudinal study aimed to investigate the characteristics and predictive risk factors of overweight among adolescents. The hypothesis was that baseline overweight predicted most overweight over time compared to other factors, especially excessive internet use.

SUBJECTS

A sample of 621 youths were followed from age 14 (T0 Spring 2012) to age 16 (T1 Spring 2014) in Switzerland. Participants were divided into two groups according to their weight at the final assessment: overweight and non-overweight. At T0, participants reported demographic, health, substance use and internet use data. A logistic regression was performed to assess the explanatory variables of overweight at T1. Data are presented as adjusted odds ratios (aORs) with 95% confidence interval.

RESULTS

The 2-year evolution showed a net BMI increase of 4.8%. Overweight adolescents were significantly more likely to be male, to live in an urban area, to be on a diet and to report using the internet more than 2 h per day on weekends at T0. However, with the addition of baseline overweight, only the excessive use of internet on weekends remained as an explanatory variable. An adolescent who was already overweight at T0 had a more than 20-fold risk (aOR 21.04) of being overweight 2 years later. Moreover, among adolescents becoming overweight between T0 and T1, internet use did not show any significant effect.

CONCLUSION

The risk of being overweight is mostly influenced by weight status at baseline compared to excessive internet use. Thus, our results do not confirm the negative effect of internet on healthier activities. Internet use could at most reinforce an already existing risk of being overweight.

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.

Developmental Trajectories of Physical Activity, Sports, and Television Viewing During Childhood to Young Adulthood: Iowa Bone Development Study

IMPORTANCE

The diverse developmental patterns of obesogenic behaviors during childhood and adolescence can be better understood by using new analytic approaches to assess the heterogeneity in variation during growth and development and to map the clustering of behavior patterns.

OBJECTIVES

To identify distinct trajectories of daily time spent in moderate- to vigorous-intensity physical activity (MVPA) from ages 5 to 19 years and to examine the associations of MVPA trajectories with sports participation and television viewing trajectories.

DESIGN, SETTING, AND PARTICIPANTS

Cohort members in the prospective population-based Iowa Bone Development Study participated in MVPA assessments via accelerometry from September 16, 1998, to December 9, 2013, at ages 5, 8, 11, 13, 15, 17, and 19 years and completed a questionnaire every 6 months on sports participation and daily time spent in television viewing.

MAIN OUTCOMES AND MEASURES

Trajectories of MVPA (minutes per day), participation in organized sports (yes or no), and television viewing time (hours per day).

RESULTS

Based on the data from 537 participants (50.1% females; 94.6% white), we identified 4 MVPA trajectories: consistently inactive (14.9%), consistently active (18.1%), decreasing moderate physical activity (52.9%), and substantially decreasing high physical activity (14.1%). All participants in the consistently inactive trajectory also followed a trajectory of no participation in sports. The consistently active trajectory was associated with decreasing an already low television viewing trajectory (P < .001).

CONCLUSIONS AND RELEVANCE

This study provided a nuanced look at the known decrease in MVPA during childhood and adolescence. Sports participation could be a critical way to avoid the consistently inactive pattern. Most important, we identified a subset of participants who maintained a seemingly healthy level of MVPA from childhood to young adulthood. The developmental pathways of physical activity and television viewing behaviors could be related. Additional studies should examine the determinants and health consequences of these specific MVPA trajectories.

Adolescents' Sedentary Behaviors in Two European Cities

PURPOSE

The aim of this study was to determine and compare the correlates of objective sedentary behavior (SB) and nonschool self-reported SB in adolescents from 2 midsized cities, 1 in France (Tarbes) and 1 in Spain (Huesca). Stability of objective SB and nonschool self-reported SB were also assessed at different time points during 1 academic year.

METHOD

Starting with a total of 829 participants and after applying inclusion criteria, objective SB was assessed for 646 adolescents (Mage = 14.30 ± 0.71 years) with GT3X accelerometers for 7 days at 2 time points. Nonschool self-reported SB was measured for 781 adolescents (Mage = 14.46 ± 0.76 years) at 3 time points by means of a questionnaire. Data were analyzed using multiple regression analysis.

RESULTS

Gender and ambient temperature emerged as the main statistically significant correlates in all objective SB models, showing higher objective SB levels in girls and lower objective SB levels when ambient temperature was higher. According to nonschool self-reported SB, a gender effect was found in almost all behaviors. Whereas boys spent more time playing with video games as well as games on their mobile phones, girls spent more time studying and using their computers and mobile phones to communicate with each other. The findings showed a statistically significant city effect on study time (Huesca > Tarbes) and video games and telephone communication time (Tarbes > Huesca).

CONCLUSION

Nonschool self-reported SB patterns were different in Huesca and Tarbes. Intervention programs should be adapted to target the reduction of adolescents' SB according to different contexts.

Are associations between electronic media use and BMI different across levels of physical activity?

Background

The use of electronic media has been found to be a risk factor for higher BMI and for being overweight. Physical activity has been found to be associated with lower BMI and lower risk for being overweight. Little is known about whether the associations between physical activity and electronic media use are additive or interactive in predicting BMI and risk for overweight among adolescents.

Methods

The data used in this study stem from the 2009/2010 survey of “Health Behaviour in School-aged Children (HBSC) study: A WHO Cross-National Survey. The sample consisted of 107184 13 and 15 year students from 30 different countries. Multilevel regression models were used to produce the presented estimates.

Results

Overall, 18% of boys and 11% of girls were classified as overweight. EM use was found to be associated with increased BMI z-scores and odds for overweight among both boys and girls who did not comply with physical activity guidelines. Among physically active adolescents, EM was found to be significantly associated with BMI or odds for overweight among girls, but not among boys.

Conclusion

While the usage of EM appear to be inconsequential for BMI and the risk of overweight among physically active boys, we find evidence indicating that EM use is associated with BMI and risk for overweight among girls, including those who report complying with MVPA guidelines.

Low physical activity and high screen time can increase the risks of mental health problems and poor sleep quality among Chinese college students

OBJECTIVE

To test the independent and interactive associations of physical activity (PA) and screen time (ST) with self-reported mental health and sleep quality among Chinese college students.

METHOD

Data were collected in October, 2013. The gender, age, residential background, body mass index (BMI), perceived family economy and perceived study burden were obtained from a total of 4747 college students (41.6% males and 58.4% females). The outcomes were self-reported PA status, ST, anxiety, depression, psychopathological symptoms and sleep quality. Analyses were conducted with logistic regression models.

RESULTS

Overall, 16.3%, 15.9% and 17.3% of the students had psychological problems, such as anxiety, depression and psychopathological symptoms, respectively. The prevalence of poor sleep quality was 9.8%. High ST was significantly positively associated with anxiety (OR=1.38, 95%CI: 1.15-1.65), depression (OR=1.76, 95%CI: 1.47-2.09), psychopathological symptoms (OR=1.69, 95%CI: 1.43-2.01) and poor sleep quality (OR=1.32, 95%CI: 1.06-1.65). High PA was insignificantly negatively associated with anxiety, depression, psychopathological symptoms and poor sleep. Low PA and high ST were independently and interactively associated with increased risks of mental health problems and poor sleep quality (p<0.05 for all).

CONCLUSION

Interventions are needed to reduce ST and increase PA in the lifestyles of young people. Future research should develop and measure the impacts of interventions and their potential consequences on sleep, health, and well being.

Sleep and use of electronic devices in adolescence: results from a large population-based study

OBJECTIVES

Adolescents spend increasingly more time on electronic devices, and sleep deficiency rising in adolescents constitutes a major public health concern. The aim of the present study was to investigate daytime screen use and use of electronic devices before bedtime in relation to sleep.

DESIGN

A large cross-sectional population-based survey study from 2012, the youth@hordaland study, in Hordaland County in Norway.

SETTING

Cross-sectional general community-based study.

PARTICIPANTS

9846 adolescents from three age cohorts aged 16-19. The main independent variables were type and frequency of electronic devices at bedtime and hours of screen-time during leisure time.

OUTCOMES

Sleep variables calculated based on self-report including bedtime, rise time, time in bed, sleep duration, sleep onset latency and wake after sleep onset.

RESULTS

Adolescents spent a large amount of time during the day and at bedtime using electronic devices. Daytime and bedtime use of electronic devices were both related to sleep measures, with an increased risk of short sleep duration, long sleep onset latency and increased sleep deficiency. A dose-response relationship emerged between sleep duration and use of electronic devices, exemplified by the association between PC use and risk of less than 5 h of sleep (OR=2.70, 95% CI 2.14 to 3.39), and comparable lower odds for 7-8 h of sleep (OR=1.64, 95% CI 1.38 to 1.96).

CONCLUSIONS

Use of electronic devices is frequent in adolescence, during the day as well as at bedtime. The results demonstrate a negative relation between use of technology and sleep, suggesting that recommendations on healthy media use could include restrictions on electronic devices.

Virtually impossible: limiting Australian children and adolescents daily screen based media use

BACKGROUND

Paediatric recommendations to limit children's and adolescents' screen based media use (SBMU) to less than two hours per day appear to have gone unheeded. Given the associated adverse physical and mental health outcomes of SBMU it is understandable that concern is growing worldwide. However, because the majority of studies measuring SBMU have focused on TV viewing, computer use, video game playing, or a combination of these the true extent of total SBMU (including non-sedentary hand held devices) and time spent on specific screen activities remains relatively unknown. This study assesses the amount of time Australian children and adolescents spend on all types of screens and specific screen activities.

METHODS

We administered an online instrument specifically developed to gather data on all types of SBMU and SBMU activities to 2,620 (1373 males and 1247 females) 8 to 16 year olds from 25 Australian government and non-government primary and secondary schools.

RESULTS

We found that 45% of 8 year olds to 80% of 16 year olds exceeded the recommended < 2 hours per day for SBMU. A series of hierarchical linear models demonstrated different relationships between the degree to which total SBMU and SBMU on specific activities (TV viewing, Gaming, Social Networking, and Web Use) exceeded the < 2 hours recommendation in relation to sex and age.

CONCLUSIONS

Current paediatric recommendations pertaining to SBMU may no longer be tenable because screen based media are central in the everyday lives of children and adolescents. In any reappraisal of SBMU exposure times, researchers, educators and health professionals need to take cognizance of the extent to which SBMU differs across specific screen activity, sex, and age.

Associations between sedentary behaviour and physical activity in children and adolescents: a meta-analysis

Physical activity and sedentary behaviour are associated with metabolic and mental health during childhood and adolescence. Understanding the inter-relationships between these behaviours will help to inform intervention design. This systematic review and meta-analysis synthesized evidence from observational studies describing the association between sedentary behaviour and physical activity in young people (<18 years). English-language publications up to August 2013 were located through electronic and manual searches. Included studies presented statistical associations between at least one measure of sedentary behaviour and one measure of physical activity. One hundred sixty-three papers were included in the meta-analysis, from which data on 254 independent samples was extracted. In the summary meta-analytic model (k = 230), a small, but significant, negative association between sedentary behaviour and physical activity was observed (r = -0.108, 95% confidence interval [CI] = -0.128, -0.087). In moderator analyses, studies that recruited smaller samples (n < 100, r = -0.193, 95% CI = -0.276, -0.109) employed objective methods of measurement (objectively measured physical activity; r = -0.233, 95% CI = -0.330, -0.137) or were assessed to be of higher methodological quality (r = -0.176, 95% CI = -0.215, -0.138) reported stronger associations, although effect sizes remained small. The association between sedentary behaviour and physical activity in young people is negative, but small, suggesting that these behaviours do not directly displace one another.

The effects of individual, family and environmental factors on physical activity levels in children: a cross-sectional study

BACKGROUND

Physical activity plays an important role in optimising physical and mental health during childhood, adolescence, and throughout adult life. This study aims to identify individual, family and environmental factors that determine physical activity levels in a population sample of children in Ireland.

METHODS

Cross-sectional analysis of the first wave (2008) of the nationally representative Growing Up in Ireland study. A two-stage clustered sampling method was used where national schools served as the primary sampling unit (response rate: 82%) and age eligible children from participating schools were the secondary units (response rate: 57%). Parent reported child physical activity levels and potential covariates (parent and child reported) include favourite hobby, total screen time, sports participation and child body mass index (measured by trained researcher). Univariate and multivariate multinomial logistic regression (forward block entry) examined the association between individual, family and environmental level factors and physical activity levels.

RESULTS

The children (N = 8,568) were classified as achieving low (25%), moderate (20%) or high (55%) physical activity levels. In the fully adjusted model, male gender (OR 1.64 [95% CI: 1.34-2.01]), having an active favourite hobby (OR 1.65 [95% CI: 1.31-2.08]) and membership of sports or fitness team (OR 1.90 [95% CI: 1.48-2.45]) were significantly associated with being in the high physical activity group. Exceeding two hours total screen time (OR 0.66 [95% CI: 0.52-0.85]), being overweight (OR 0.41 [95%CI: 0.27-0.61]; or obese (OR 0.68 [95%CI: 0.54-0.86]) were significantly associated with decreased odds of being in the high physical activity group.

CONCLUSIONS

Individual level factors appear to predict PA levels when considered in the multiple domains. Future research should aim to use more robust objective measures to explore the usefulness of the interconnect that exists across these domains. In particular how the family and environmental settings could be useful facilitators for consistent individual level factors such as sports participation.

Evidence-based guidelines for wise use of electronic games by children

Electronic games (e-games) are widely used by children, often for substantial durations, yet to date there are no evidence-based guidelines regarding their use. The aim of this paper is to present guidelines for the wise use of e-games by children based on a narrative review of the research. This paper proposes a model of factors that influence child-e-games interaction. It summarises the evidence on positive and negative effects of use of e-games on physical activity and sedentary behaviour, cardio-metabolic health, musculoskeletal health, motor coordination, vision, cognitive development and psychosocial health. Available guidelines and the role of guidelines are discussed. Finally, this information is compiled into a clear set of evidence-based guidelines, about wise use of e-games by children, targeting children, parents, professionals and the e-game industry. These guidelines provide an accessible synthesis of available knowledge and pragmatic guidelines based on e-game specific evidence and related research.

Which type of sedentary behaviour intervention is more effective at reducing body mass index in children? A meta-analytic review

Sedentary behaviour is emerging as an independent risk factor for paediatric obesity. Some evidence suggests that limiting sedentary behaviour alone could be effective in reducing body mass index (BMI) in children. However, whether adding physical activity and diet-focused components to sedentary behaviour reduction interventions could lead to an additive effect is unclear. This meta-analysis aims to assess the overall effect size of sedentary behaviour interventions on BMI reduction and to compare whether interventions that have multiple components (sedentary behaviour, physical activity and diet) have a higher mean effect size than interventions with single (sedentary behaviour) component. Included studies (n = 25) were randomized controlled trials of children (<18 years) with intervention components aimed to reduce sedentary behaviour and measured BMI at pre- and post-intervention. Effect size was calculated as the mean difference in BMI change between children in an intervention group and a control group. Results indicated that sedentary behaviour interventions had a significant effect on BMI reduction. The pooled effect sizes of multi-component interventions (g = -0.060∼-0.089) did not differ from the single-component interventions (g = -0.154), and neither of them had a significant effect size on its own. Future paediatric obesity interventions may consider focusing on developing strategies to decrease multiple screen-related sedentary behaviours.

Recommendations for promoting physical activity for children and adolescents in Germany. A consensus statement

Increasing physical activity and reduction of sedentary behaviour play important roles in health promotion and prevention of lifestyle-related diseases in children and adolescents. However, the question of how much physical activity is useful for which target group is still a matter of debate. International guidelines (World Health Organization; European Association for the Study of Obesity), which are mainly based on expert opinions, recommend 60 min of physical activity every day. Age- and sex-specific features and regional differences are not taken into account. Therefore, expert consensus recommendations for promoting physical activity of children and adolescents in Germany were developed with special respect to national data, but also with respect to aspects of specific target groups, e.g., children with a lower socio-economic status (SES) or with migration background. They propose 90 min/day of physical activity, or at least 12,000 steps daily. Additionally, lifestyle factors, especially restriction of media consumption, were integrated. The recommendations provide orientation for parents and caregivers, for institutions such as schools and kindergartens as well as for communities and stakeholders.

Excess screen time in US children: association with family rules and alternative activities

We describe the association of screen time in excess of American Academy of Pediatrics recommendations (≤2 h/d) with family television-use policies and regular nonscreen activities among US school-aged children. Data from the 2007 National Survey of Children's Health were used. The sum of minutes spent on television, videos, video games, and recreational computer use was calculated for children 6 to 17 years old. Bivariate and multivariate logistic regression models were used to calculate relative odds of exceeding American Academy of Pediatrics guidelines and of heavy screen use (>4 h/d) for varying family media-use policies and frequency of alternative activities (physical activity and family meals). In all, 49% of school-aged children had screen time >2 h/d and 16% had screen time >4 h/d. Lower frequency of family meals, presence of TV in the bedroom, absence of rules about TV viewing, and less physical activity were associated with both >2 and >4 hours per day of screen time.

Interventions designed to reduce sedentary behaviours in young people: a review of reviews

BACKGROUND

Leisure time is increasingly spent in sedentary pursuits such as screen-viewing (eg, television/DVD viewing and computer use), motorised travel, school/work and sitting-based socialising (eg, social media and chatting). Sedentary screen time, particularly TV, appears to play an important role in the aetiology of obesity due to its co-occurrence with other unhealthy behaviours such as snacking on energy-dense foods, low levels of physical activity and inadequate sleep. More information is needed on how to reduce sedentary behaviours. Most interventions have focused on young people and a number of systematic reviews exist on this topic.

OBJECTIVE

To synthesise systematic reviews and meta-analyses of interventions aimed at decreasing sedentary behaviours among children and adolescents.

METHODS

Papers were located from computerised and manual searches. Included articles were English language systematic reviews or meta-analyses of interventions aiming at reducing sedentary behaviour in children (<11 years) and adolescents (12-18 years).

RESULTS

Ten papers met the inclusion criteria and were analysed. All reviews concluded some level of effectiveness in reducing time spent in sedentary behaviour. When an effect size was reported, there was a small but significant reduction in sedentary time (highest effect size=-0.29; CI -0.35 to -0.22). Moderator analyses showed a trend favouring interventions with children younger than 6 years. Effective strategies include the involvement of family, behavioural interventions and electronic TV monitoring devices.

CONCLUSIONS

Results from systematic reviews and meta-analyses show that interventions to reduce children's sedentary behaviour have a small but significant effect. Future research should expand these findings examining interventions targeting different types of sedentary behaviours and the effectiveness of specific behaviour change techniques across different contexts and settings.

Birth weight and time spent in outdoor physical activity during adolescence

PURPOSE

We investigated the association between birth parameters (weight, length, and head circumference) and time spent in physical activity (outdoor and indoor) and screen time (TV viewing, computer, and videogame usage) among adolescents.

METHODS

A longitudinal cohort study surveyed 1794 children in 2004-2005 (median age = 12.7 yr), and 752 were resurveyed 5 yr later in 2009-2010 (age = 17-18 yr). Adolescents completed detailed activity questionnaires. Parents extracted birth parameter data from their child's health record booklet.

RESULTS

After adjusting for age, sex, ethnicity, gestational age, parental education, home ownership, exposure to passive smoking, and body mass index, 12-yr-old children in the highest compared with the lowest quartile of birth weight spent on average approximately 56 and 62 min more in total (Ptrend = 0.02) and outdoor physical activity (Ptrend = 0.02) per week, respectively. Similarly, 12-yr-old children in the high (>4000 g) versus very low (<2000 g) birth weight group spent approximately 1.3 h·wk more in outdoor activity (Ptrend = 0.02). Among those age 17-18 yr, increasing birth weight (lowest to highest quartile) was associated with greater time spent in outdoor physical activity (∼1 h·wk-1, Ptrend = 0.04). Significant associations were not observed between all birth parameters and recreational screen time. Also, no associations were observed between head circumference or birth length with physical activity and screen time.

CONCLUSIONS

Birth weight could be a potential determinant of physical activity, but not of screen time during adolescence. Hence, this could be part of the underlying mechanism between prenatal influences and future disease risk and could have possible clinical implications.

Conceptual understanding of screen media parenting: report of a working group

Screen media (television, computers, and videogames) use has been linked to multiple child outcomes, including obesity. Parents can be an important influence on children's screen use. There has been an increase in the number of instruments available to assess parenting in feeding and physical activity contexts, however few measures are available to assess parenting practices regarding children's screen media use. A working group of screen media and parenting researchers convened at the preconference workshop to the 2012 International Society for Behavioral Nutrition and Physical Activity (ISBNPA) annual meeting, "Parenting Measurement: Current Status and Consensus Reports," to identify and prioritize issues in assessing screen media parenting practices. The group identified that screen media use can pose different risks for children, depending on their age and developmental stage, across physiologic, psychosocial, and development outcomes. With that in mind, a conceptual framework of how parents may influence their child's screen-viewing behaviors was proposed to include the screen media content, context of viewing, and amount viewed. A research agenda was proposed to prioritize a validation of the framework and enhance the ability of researchers to best assess parenting influences across the three domains of content, context and amount of children's screen media use.

Understanding the physical and social contexts of children's nonschool sedentary behavior: an ecological momentary assessment study

BACKGROUND

Research on children's sedentary behavior has relied on recall-based self-report or accelerometer methods, which do not assess the context of such behavior.

PURPOSE

This study used ecological momentary assessment (EMA) to determine where and with whom children's sedentary behavior occurs during their nonschool time.

METHODS

Children (N = 120) ages 9-13 years (51% male, 33% Hispanic) wore mobile phones that prompted surveys (20 total) for 4 days. Surveys measured current activity (eg, exercise, watching TV), physical location (eg, home, outdoors), and social company (eg, family, friends).

RESULTS

Children engaged in a greater percentage of leisure-oriented (eg, watching TV) than productive (eg, reading, doing homework) sedentary behavior (70% vs 30%, respectively). Most of children's sedentary activity occurred at home (85%). Children's sedentary activity took place most often with family members (58%). Differences in physical context of sedentary behavior were found for older vs. younger children (P < .05). Type of sedentary behavior differed by gender, racial/ethnic group, and social context (P < .05).

CONCLUSION

Children may prefer or have greater opportunities to be sedentary in some contexts than others. Research demonstrates the potential for using EMA to capture real-time information about children's sedentary behavior during their nonschool time.

Changes in screen time activity in Norwegian children from 2001 to 2008: two cross sectional studies

Background

There has been an increase in screen-based communication, leading to concerns about the negative health effects of screen-based activities in children and adolescents. The present study aimed to (1) analyze changes in screen time activity in Norwegian children from 2001 to 2008, and (2) to analyze associations between the changes in screen time activity over time and sex, grade level and parental educational level.

Methods

Within the project Fruits and Vegetables Make the Marks (FVMM), 1488 6^th and 7^th grade pupils from 27 Norwegian elementary schools completed a questionnaire including a question about time spent on television viewing and personal computer use in 2001 and 1339 pupils from the same schools completed the same questionnaire in 2008. Data were analyzed by multilevel linear mixed models.

Results

The proportions of 6^th and 7^th grade pupils at the 27 schools that reported screen time activity outside school of 2 hours/day or more decreased from 55% to 45% (p<0.001) from 2001 to 2008 when adjusting for sex, grade level and parental education. The decrease was most evident in 6^th graders (51% to 37%) and in children with highly educated parents (54% to 39%).

Conclusion

The present study shows that there has been a marked reduction in screen time activity outside school in this group of Norwegian 10–12 year olds from 2001 to 2008.