Is television viewing a suitable marker of sedentary behavior in young people?

Full-Day Physical Activity and Sedentary Behaviour Levels of Typically Developing Children and Adolescents in the Middle East: A Systematic Review

Physical activity (PA) and sedentary behaviour (SB) are important components of physical behaviour associated with long-term health outcomes. Environmental and cultural factors may influence physical behaviour. To explore full day PA and SB in children and adolescents (2-18 years old) in the Middle East, a systematic literature review was performed including 183 journal articles. A wide range of PA and SB outcomes were reported, in some cases making synthesis of results difficult. As a consequence, results were generally reported narratively (MVPA time, total PA, SB time). Meta-regression of daily step count revealed females took 4600 fewer steps than males, with 3000 fewer steps on weekdays than weekends, and overweight individuals taking 2800 fewer steps/day. Steps decreased with age. Meta-regression for TV viewing time demonstrated an increase by 0.04 h per year of age. Even though environmental and cultural conditions may be different, PA and SB of children and adolescents in the Middle East were largely comparable to those of Europeans and North Americans. The wide range of data collection instruments used (both self-report questionnaire and body-worn devices) and heterogeneity of data made synthesis of reported data across studies very difficult, suggesting a need for greater standardisation of data collection methods.

Organized Youth Sports Trajectories and Adult Health Outcomes: The Young Finns Study

INTRODUCTION

This study identified the trajectories of organized youth sports over 9 years in youths aged 9-18 years and examined whether the trajectories predicted physical activity, sedentary behavior, and obesity in midlife.

METHODS

Self-reported organized youth sports trajectories were identified for participants between 1980 and 1989 (N=3,474). Accelerometer-derived physical activity was quantified for participants (n=1,349) in 2018-2020. Sociodemographic, physical activity, and TV viewing data were collected through questionnaires either at baselines or follow-up. Adult BMI was calculated to clarify obesity. Associations of organized youth sports trajectories with adult physical activity, sedentary behavior, and obesity were evaluated using mixture models, which were stratified by sex and conducted in 2022.

RESULTS

Three organized youth sports trajectories were identified for boys and girls (sustained high-sports participation, 12.0%/7.5%; sustained moderate-sports participation, 14.0%/13.3%; and low-sports/nonparticipation, 74.0%/79.2%). Boys sustaining both moderate- and high-sports participation had higher levels of adult self-reported physical activity (β=0.59, p=0.007; β=0.69, p<0.001) than low-sports/nonparticipating boys. Girls sustaining both moderate- and high-sports participation accumulated more total physical activity (β=113.4, p=0.009; β=144.3, p=0.002), moderate-to-vigorous physical activity (β=7.86, p=0.016; β=14.01, p<0.001), step counts (β=1,020, p=0.003; β=1,045, p=0.005), and self-reported physical activity (β=0.79, p<0001; β=0.63, p=0.003) in midlife than their low-sports/nonparticipating counterparts. Girls sustaining moderate-sports participation accumulated more light-intensity physical activity (β=19.79, p=0.012) and less sedentary time (β= -27.65, p=0.002), and those sustaining high-sports participation had lower obesity prevalence (OR=0.41, p=0.009) 40 years later than low-sports/nonparticipating girls.

CONCLUSIONS

Sustained participation in organized youth sports is independently predictive of physical activity patterns, sedentary time, and obesity in midlife, especially in girls, thus contributing to the development of a healthy and active lifestyle across the life course.

Parental Perception of the Social and Physical Environment Contributes to Gender Inequalities in Children's Screen Time

BACKGROUND

This cross-sectional study aimed to explore how parental perceptions of the social and physical environment of the neighborhood was associated with 3- to 10-year-old children's use of traditional and modern screen devices.

METHODS

Participants were recruited under the scope of the project ObesInCrisis, conducted in 2016-2017 in the cities of Porto, Coimbra, and Lisbon (Portugal). Data from 6347 children aged 3-10 years were analyzed (3169 boys [49.9%]). A parental questionnaire was used to collect data on children's screen time (dependent variable) and parents' perceived social and physical environment (from the Environmental Module of the International Physical Activity Prevalence Study questionnaire; independent variable), parental education, and urbanization (used as covariates).

RESULTS

Neighborhood features were more correlated with girls' screen time, than with boys', particularly among younger children. Also, more social than physical characteristics of the neighborhood were positively associated with children's use of television and mobile devices (ie, tablet and smartphone).

CONCLUSIONS

Community-based approaches should improve the social environment and implement supervised after-school programs to encourage and support children to be outdoors and spend less time in sedentary pursuits.

Measurement of physical activity and sedentary behavior in national health surveys, South America

Objectives.

To characterize how physical activity and sedentary behavior have been measured in national health surveys in South American countries.

Methods.

An extensive search was made for national health surveys from all 12 South American countries through health websites, national statistical offices, and contact with researchers and policy-makers. The following eligibility criteria were used to select surveys: conducted in a South American country; used a nationally representative sample ≥ 18 years; coordinated by the public, private or mixed private–public sector; and assessed physical activity and/or sedentary behavior. Data were extracted on general information about the surveys, specific details about the physical activity and sedentary behavior assessment, and additional questions related to activity behavior.

Results.

In total, 36 surveys were included, two of which were multicountry surveys; all surveys assessed physical activity and 27 assessed sedentary behavior. Most surveys (23/36; 64%) were based on previously validated international questionnaires, but 13 (57%) of these deviated from the reference tools, introducing changes and adaptations. Sedentary behavior was assessed mostly through questions on screen time and/or daily sitting time in the same physical activity questionnaires. No survey used device-based measures to generate data on these behaviors.

Conclusions.

Differences between instruments used and modifications limit the comparability of data across countries. This highlights the importance of standardizing assessment within South America for physical activity and sedentary behavior sections in national surveys, with the broader aim of contributing to establishing a standardized strategy for the surveillance of physical activity and sedentary behavior in South America.

Parental Working Hours and Children's Sedentary Time: A Cross-sectional Analysis of the J-SHINE

BACKGROUND

Sedentary behaviors are prevalent among children and can have a detrimental effect on their health. Little is known about the influence of parental time on children's sedentary behavior. This study examined the association between parental working hours and children's sedentary time.

METHODS

Cross-sectional data were drawn from the Japanese Study on Stratification, Health, Income, and Neighborhood (J-SHINE) in 2010 and 2011. Participants were 886 children aged 7-18 years and their parents. The primary outcome was self-reported sedentary time after school that comprised screen time and non-screen time. The main explanatory variable was parental working hours. We used multiple regression analysis adjusting for sociodemographic factors.

RESULTS

Children's mean sedentary time was 222 (standard deviation [SD], 123) min/day; 144 (SD, 108) min/day screen time and 78 (SD, 65) min/day non-screen time. Children whose mothers worked ≥20 hours/week had 28 (95% CI, 9 to 48) min/day longer sedentary time than children of homemakers (240 min/day vs 214 min/day). The longer maternal working hours, the longer sedentary time (P for trend <0.01). In contrast, children whose fathers worked ≥48 hours/week had 82 (95% CI, -156 to -7) min/day shorter sedentary time than children of non-working fathers (179 min/day vs 264 min/day). When limited to children whose fathers worked, there was no statistically significant association between children's sedentary time and paternal working hours.

CONCLUSIONS

Children with mothers who work long hours or fathers not working tend to sit more. Supplementing the shortages in resources for childcare may be necessary among those families.

The 24-h Movement Compositions in Weekday, Weekend Day or Four-Day Periods Differentially Associate with Fundamental Movement Skills

The aim of this study was to investigate the relationship between weekday, weekend day and four-day physical activity (PA) behaviours and fundamental movement skills (FMS) in British preschool children from a low socio-economic status background using compositional data analysis (CoDA). One hundred and eighty-five preschool children aged 3-4 years provided objectively assessed PA and sedentary behaviour (SB) data (GENEActiv accelerometer) and FMS (TGMD-2). The association of 24-h movement behaviours with FMS was explored using CoDA and isotemporal substitution (R Core Team, 3.6.1). When data were considered compositionally (SB, light PA (LPA), moderate and vigorous PA (MVPA)) and adjusted for age, BMI and sex, the weekday-derived composition predicted total motor competence (r² = 0.07), locomotor (r² = 0.08) and object control skills (r² = 0.09); the weekend day-derived composition predicted total motor competence (r² = 0.03) and object control skills (r² = 0.03), the 4-day-derived composition predicted total motor competence (r² = 0.07), locomotor (r² = 0.07) and object control skills (r² = 0.06) (all p < 0.05). Reallocation of 5 min of LPA at the expense of any behaviour was associated with significant improvements in total motor competence, locomotor and object control skills; for weekend-derived behaviours, MVPA was preferential. Considering movement behaviours over different time periods is required to better understand the effect of the 24-h movement composition on FMS in preschool children.

Comparing three screen-based sedentary behaviours' effect upon adolescents' participation in physical activity: The ESSENS study

Background

Literature focusing on the association between sedentary behaviours and physical activity has provided equivocal results and has been dominated by TV viewing as the indicator of sedentary behaviour. There is a need for more studies exploring the association between contemporary screen activities and physical activity among youth.

Methods

A cross-sectional study including 742 adolescents was conducted in 2016. Data were collected at school through an online questionnaire. Regression analyses were used to explore the association between different screen-based sedentary behaviours and participation in physical activity.

Results

The results showed that those with lower (vs higher) time spent on TV/movie streaming and electronic game playing both on weekdays and weekend days had significantly higher odds of participating in physical activity. There were no significant associations between socializing/surfing online both on weekdays and weekend days and physical activity in adjusted models.

Conclusions

TV/movie streaming and electronic game playing during both weekdays and weekend days were significantly inversely related with participating in physical activity. Initiatives aimed at reducing screen-based sedentary activities might result in favourable effects on physical activity levels among adolescents.

Parental Attitudes to Childhood Overweight: The Multiple Paths through Healthy Eating, Screen Use, and Sleeping Time

The main goal of this paper is to examine how parental attitudes toward sleeping, screen use, and feeding their child influence the child's body mass index (BMI) through the child's behaviors related to time dedicated to sleep and television, and their healthy eating. Using survey data from 908 parents, results show that parental attitudes have a significant influence on children's behavior and, more importantly, on their BMI. The three forms of a child's behavior (sleeping, watching TV, and healthy eating patterns) are affected by what parents do and their attitudes toward these three behaviors at home. Results show how changes in parental attitudes are an interesting target to prevent the child's overweight.

Physical behaviors and fundamental movement skills in British and Iranian children: An isotemporal substitution analysis

Although the relationship between fundamental movement skills (FMS) and physical behaviors has been established, differences between countries are scarcely explored. The impact of the whole physical behavior composition, in relation to FMS, has yet to be investigated in 9-11 y children. The aims were to investigate the associations of substitution of physical behaviors with FMS score and to compare traditional linear regression and compositional data analysis and compare between England and Iran. Measures included accelerometer-derived activity (sleep (SL), sedentary behavior (SB), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) and FMS, using the TGMD-2, in 119 children (64 boys) from Iran (mean (±SD) age: 9.8 ± 0.3 y; BMI of 18.2 ± 3.3 kg/m² ) and 139 (61 boys) children from England (mean (±SD) age: 9.5 ± 0.6 y; BMI of 17.7 ± 3.1 kg/m² ). Isometric log-ratio multiple linear regression models were used to discern the association between FMS and the mean activity composition, and for new compositions, where fixed durations of time were reallocated from one behavior to another, while the remaining behaviors were unchanged. In physical behaviors as a composition, FMS was significantly associated in both ethnicities. English children responded significantly positively to adding 5 or more minutes LPA at the expense of SB (FMS unit change from 0.05 [0.01, 0.09] at 5 minutes to 0.72 [0.01, 1.34] at 60 minutes). Adding 10 minutes or more of SL, at the expense of SB, was associated with a significant, positive change in FMS in all children. Investigation is needed to understand the composition of SB and its potential influence on FMS development.

mHealth technology for ecological momentary assessment in physical activity research: a systematic review

OBJECTIVE

To systematically review the publications on ecological momentary assessment (EMA) relating to physical activity (PA) behavior in order to classify the methodologies, and to identify the main mHealth technology-based tools and procedures that have been applied during the first 10 years since the emergence of smartphones. As a result of this review, we want to ask if there is enough evidence to propose the use of the term "mEMA" (mobile-based EMA).

DESIGN

A systematic review according to PRISMA Statement (PROSPERO registration: CRD42018088136).

METHOD

Four databases (PsycINFO, CINALH, Medline and Web of Science Core Collection) were searched electronically from 2008 to February 2018.

RESULTS

A total of 76 studies from 297 potential articles on the use of EMA and PA were included in this review. It was found that 71% of studies specifically used "EMA" for assessing PA behaviors but the rest used other terminology that also adjusted to the inclusion criteria. Just over half (51.3%) of studies (39) used mHealth technology, mainly smartphones, for collecting EMA data. The majority (79.5%) of these studies (31 out of 39) were published during the last 4 years. On the other hand, 58.8% of studies that only used paper-and-pencil were published during the first 3 years of the 10-year period analyzed. An accelerometer was the main built-in sensor used for collecting PA behavior by means of mHealth (69%). Most of the studies were carried out on young-adult samples, with only three studies in older adults. Women were included in 60% of studies, and healthy people in 82%. The studies lasted between 1 and 7 days in 57.9%, and between three and seven assessments per day were carried out in 37%. The most popular topics evaluated together with PA were psychological state and social and environmental context.

CONCLUSIONS

We have classified the EMA methodologies used for assessing PA behaviors. A total of 71% of studies used the term "EMA" and 51.3% used mHealth technology. Accelerometers have been the main built-in sensor used for collecting PA. The change of trend in the use of tools for EMA in PA coincides with the technological advances of the last decade due to the emergence of smartphones and mHealth technology. There is enough evidence to use the term mEMA when mHealth technology is being used for monitoring real-time lifestyle behaviors in natural situations. We define mEMA as the use of mobile computing and communication technologies for the EMA of health and lifestyle behaviors. It is clear that the use of mHealth is increasing, but there is still a lot to be gained from taking advantage of all the capabilities of this technology in order to apply EMA to PA behavior. Thus, mEMA methodology can help in the monitoring of healthy lifestyles under both subjective and objective perspectives. The tendency for future research should be the automatic recognition of the PA of the user without interrupting their behavior. The ecological information could be completed with voice messages, image captures or brief text selections on the touch screen made in real time, all managed through smartphone apps. This methodology could be extended when EMA combined with mHealth are used to evaluate other lifestyle behaviors.

Reliability and validity of a sedentary behavior questionnaire for South American pediatric population: SAYCARE study

Background

Multicenter studies from Europe and the United States have developed specifically standardized questionnaires for assessing and comparing sedentary behavior, but they cannot be directly applied for South American countries. The aim of this study was to assess the reliability and validity of the South American Youth Cardiovascular and Environmental (SAYCARE) sedentary behavior questionnaire.

Methods

Children and adolescents from seven South American cities were involved in the test-retest reliability (children: n = 55; adolescents: n = 106) and concurrent validity (children: n = 93; adolescents: n = 94) studies. The SAYCARE sedentary behavior questionnaire was administered twice with two-week interval and the behaviors were parent-reported for children and self-reported for adolescents. Questions included time spent watching television, using a computer, playing console games, passive playing (only in children) and studying (only in adolescents) over the past week. Accelerometer was used for at least 3 days, including at least one weekend day. We compared values of sedentary time, using accelerometers, by quartiles of reported sedentary behavior time and their sum.

Results

The reliability of sedentary behavior time was moderate for children (rho ≥0.45 and k ≥ 0.40) and adolescents (rho ≥0.30). Comparisons between the questionnaire and accelerometer showed a low overall agreement, with the questionnaire systematically underreporting sedentary time in children (at least, − 332.6 ± 138.5 min/day) and adolescents (at least, − 399.7 ± 105.0 min/day).

Conclusion

The SAYCARE sedentary behavior questionnaire has acceptable reliability in children and adolescents. However, the findings of current study indicate that SAYCARE questionnaire is not surrogate of total sedentary time.

Determinants of change in accelerometer-assessed sedentary behaviour in children 0 to 6 years of age: A systematic review

Sedentary behaviour tracks from early to middle childhood, suggesting the need to intervene early. The aim of this systematic review was to identify determinants of change in accelerometer-assessed sedentary behaviour in young children, with a view to informing interventions. Ten electronic databases were searched. Longitudinal and intervention studies were included if they (a) targeted sedentary behaviour in young children (less than of equal to 6 years), (b) assessed change in accelerometer-assessed sedentary behaviour, and (c) reported on at least one determinant of change in sedentary behaviour. Intervention components were coded according to clusters of behaviour change technique (BCT) (ie, grouping similar BCTs components). Data synthesis was guided by the socioecological model. Sixteen studies (four longitudinal; 12 intervention) met the inclusion criteria. Two (out of five identified determinants) were associated with an increase in sedentary behaviour in longitudinal studies: the after childcare/school period and transition from childcare to school. Three (out of 21 identified determinants) were associated with a decrease in sedentary behaviour in intervention studies: "goals and planning" (ie, "behavioural contract"), "repetition and substitution" (ie, "graded tasks"), and "reward and treat" (ie, "incentives"). The environmental and interpersonal determinants identified in this review may help to inform behavioural strategies, timing, and settings for future interventions.

Striking a Balance: Physical Activity, Screen-Viewing and Homework during the Transition to Secondary School

Physical activity levels decline, and screen-viewing behaviours increase during childhood and adolescence. The transition to secondary school appears to coincide with a sharp decline in physical activity. Parents have the potential to influence their child’s behaviours, yet little is known about their expectations for their child’s physical activity and screen-viewing during this transition. This paper explores parents’ expectations for their children’s physical activity and screen-viewing as they transition from primary to secondary school, and their proposed strategies for managing these behaviours during this time. Forty-two parents of children aged 10–11 years participated in a semi-structured telephone interviews in July 2017 or March 2018. The interview data were analysed via inductive and deductive content analysis to explore parents’ perceptions of physical activity and screen-viewing during the transition, the reasons for their perceptions, and the strategies they intended to implement to help their child balance their behaviours. Most parents expected both physical activity and screen-viewing to increase during this transition. There were several individuals, social and school-level factors influencing these expectations. Overall, parents felt that helping their child balance their activity levels, screen-viewing and homework would be challenging.

Systematic review of sedentary behaviour in people with Down syndrome across the lifespan: A clarion call

BACKGROUND

Individuals with Down syndrome (DS) experience health disparities possibly associated with high levels of sedentary behaviour (SB). We systematically reviewed SB measurement, levels, patterns, correlates, consequences and interventions in people with DS across the lifespan.

METHOD

We searched these databases: Embase; PubMed; Web of Science; Scopus; CINAHL; PsycINFO; SPORTDiscus; and Cochrane Library. We included quantitative studies published in English since 1 January 1990.

RESULTS

We identified 17 eligible articles. Across studies, accelerometer-determined sedentary time was 552 min/day (median: 542; range 392-680 min/day). Sedentary time appeared higher than previously reported values in the general population, especially for youth with DS. Multivariate SB correlates were primarily familial and environmental. Sedentary behaviour consequences have not been exclusively studied. Motor skills training reduced SB in youth with DS.

CONCLUSIONS

Sedentary behaviour research in this population is in early stages. Individuals with DS have high levels of SB that may be responsive to interventions.

High sedentary time in children is not only due to screen media use: a cross-sectional study

Background

Sedentary behaviour has become a growing public health concern. Currently, it is a common belief that screen time (SCT) is a key factor in high overall sedentary time (ST) and is often used as a primary outcome. However, the evidence is lacking. Therefore, this study investigated the association of objectively assessed total ST with SCT among children. Further, SCT was investigated separately for sedentary level, weight status, gender, and migration background.

Methods

For 198 primary school children (7.1 ± 0.7 years, boys: 43.9%) ST was assessed objectively using a multi-sensor device (Actiheart®; CamNtech, Cambridge, UK). The sample was split into three groups (tertiles) to investigate SCT of children with low, medium and high ST. SCT and socio-demographic parameters, such as migration background, were assessed using a parental questionnaire; anthropometric data was collected at schools.

Results

Absolut SCT did not differ significantly among the three sedentary groups: Daily average of SCT was 83.8 ± 55.0 min (27.4% of ST) for children with high ST, 82.8 ± 50.5 min (39.8% of ST) for children with medium ST, and 77.2 ± 59.4 min (71.3% of ST) for those with low ST. However, relatively the SCT percentage of total ST was significantly higher among children with low ST (p < 0.01). Significantly higher SCT was found in children with migration background (p < 0.01), while underweight children had significantly less SCT (p < 0.05). An association of total SCT and overall ST was found for the whole sample (B = 17.11, [2.75; 31.48], p = 0.02), but did not remain when analysis were separated for the groups, except for normal weight children (B = 15.97, [0.13; 31.81], p = 0.05).

Conclusions

The amount of SCT is the same among high, low and medium sedentary children, and high ST is largely independent of SCT. Therefore, SCT cannot be the key contributor to high ST and should not solely be used for predicting or changing children’s sedentary behaviour. Moreover, children’s weight status to classify activity levels and the role of possible compensation mechanisms should be considered in future research and when trying to intervene on ST.

Trial registration

German Clinical Trials Register (DRKS), DRKS-ID: DRKS00000494 DATE: 25/08/2010.

Methodology Used in Ecological Momentary Assessment Studies About Sedentary Behavior in Children, Adolescents, and Adults: Systematic Review Using the Checklist for Reporting Ecological Momentary Assessment Studies

Background

The use of ecological momentary assessment (EMA) to measure sedentary behavior (SB) in children, adolescents, and adults can increase the understanding of the role of the context of SB in health outcomes.

Objective

The aim of this study was to systematically review literature to describe EMA methodology used in studies on SB in youth and adults, verify how many studies adhere to the Methods aspect of the Checklist for Reporting EMA Studies (CREMAS), and detail measures used to assess SB and this associated context.

Methods

A systematic literature review was conducted in the PubMed, Scopus, Web of Science, PsycINFO, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and SPORTDiscus databases, covering the entire period of existence of the databases until January 2018.

Results

This review presented information about the characteristics and methodology used in 21 articles that utilized EMA to measure SB in youth and adults. There were more studies conducted among youth compared with adults, and studies of youth included more waves and more participants (n=696) than studies with adults (n=97). Most studies (85.7%) adhered to the Methods aspect of the CREMAS. The main criteria used to measure SB in EMA were self-report (81%) with only 19% measuring SB using objective methods (eg, accelerometer). The main equipment to collect objective SB was the ActiGraph, and the cutoff point to define SB was <100 counts/min. Studies most commonly used a 15-min window to compare EMA and accelerometer data.

Conclusions

The majority of studies in this review met minimum CREMAS criteria for studies conducted with EMA. Most studies measured SB with EMA self-report (n=17; 81.0%), and a few studies also used objective methods (n=4; 19%). The standardization of the 15-min window criteria to compare EMA and accelerometer data would lead to a comparison between these and new studies. New studies using EMA with mobile phones should be conducted as they can be considered an attractive method for capturing information about the specific context of SB activities of young people and adults in real time or very close to it.

The prospective association between objectively measured sedentary time, moderate-to-vigorous physical activity and cardiometabolic risk factors in youth: a systematic review and meta-analysis

Sedentary time and moderate-to-vigorous physical activity (MVPA) may be uniquely related to cardiometabolic health. Excessive sedentary time is suggested as an independent cardiometabolic risk factor, while MVPA is favourably associated with cardiometabolic health. This systematic review and meta-analysis summarizes the evidence on a prospective relationship between objectively measured sedentary time, MVPA and cardiometabolic health indicators in youth. PubMed, Embase, CINAHL, PhyscINFO and SPORTDiscus were systematically searched from January 2000 until April 2018. Studies were included if sedentary time and physical activity were measured objectively and examined associations with body mass index, waist circumference, triglycerides, high-density lipoprotein, insulin, blood pressure or the clustering of these cardiometabolic risk factors. We identified 30 studies, of which 21 were of high quality. No evidence was found for an association between sedentary time and cardiometabolic outcomes. The association between MVPA and individual cardiometabolic risk factors was inconsistent. The meta-analysis for prospective studies found a small but significant effect size between MVPA at baseline and clustered cardiometabolic risk at follow-up (ES -0.014 [95% CI, -0.024 to -0.004]). We conclude that there is no prospective association between sedentary time and cardiometabolic health, while MVPA is beneficially associated with cardiometabolic health in youth.

Factors associated with objectively measured total sedentary time and screen time in children aged 9-11 years

OBJECTIVE

To identify factors associated with total sedentary time and screen time in children aged 9-11 years.

METHODS

For seven consecutive days, 328 children (51.5% boys) used accelerometers to monitor total sedentary time. Screen time was calculated by the self-reporting method. Individual, family, family environment, and school environment questionnaires were filled out. Body composition was measured using a Tanita scale.

RESULTS

The mean sedentary time was 500min/day (boys: 489, girls: 511, p=0.005), and mean screen time was 234min/day (boys: 246, girls: 222, p=0.053). In both genders, factors associated with sedentary time were healthy dietary pattern and moderate-to-vigorous physical activity. In boys, only moderate-to-vigorous physical activity was significant; in girls, the healthy dietary pattern, moderate-to-vigorous physical activity, and transportation to school were significant. As for the screen time, the associated factors were body mass index and healthy dietary pattern (both genders). In boys, the associated factors were body mass index, healthy dietary pattern, and television in the bedroom. In girls, the associated factors were healthy dietary pattern, transportation to school, and physical activity policies or practice at school.

CONCLUSION

Several associated factors were identified in the association between total sedentary time and screen time in children; however, only the healthy dietary pattern was common between sedentary time and screen time.

The Association between Children's and Parents' Co-TV Viewing and Their Total Screen Time in Six European Countries: Cross-Sectional Data from the Feel4diabetes-Study

In many European children, high levels of screen time can be found, which is associated with several adverse health outcomes. Therefore, there is a need for identifying effective intervention strategies that reduce screen time in children. A factor that may contribute to excessive screen time in children may be “co-TV viewing” (i.e., the time that parents and children spend on watching TV together), as parents often recognize the importance of limiting children’s (individual) screen time, but often encourage TV viewing as a family because of its perceived benefits (e.g., educational purposes). The primary aim of this study was to investigate the (sex-specific) association between co-TV viewing and both children’s and parents’ screen time, and these associations were investigated across and within six European countries. In total, 10,969 parents (Mean_age = 40.7 ± 5.3 years, Mean_BMI = 24.4 ± 4.6) of primary school children (Mean_age = 8.2 ± 1.0 years, 49.0% boys, Mean_BMI = 17.3 ± 2.8) completed a questionnaire assessing co-TV viewing and screen time. Multilevel regression analyses were conducted. Across countries, positive associations were found between co-TV viewing and both children’s (β = 11.85, SE = 3.69, p < 0.001) and parents’ screen time (β = 14.47, SE = 4.43, p = 0.001). Similar associations were found in most (but not all) countries. The results suggest that targeting co-TV viewing might be a promising intervention strategy because of its potential to limit screen time of both children and parents.

Disentangling the relationship between sedentariness and obesity: Activity intensity, but not sitting posture, is associated with adiposity in women

BACKGROUND

The relationship between free-living sedentary behaviour (SB) and obesity is unclear. Studies may arrive at disparate conclusions because of inconsistencies and limitations when defining and measuring free-living SB. The aim of this cross-sectional study was to examine whether the relationship between SB and adiposity differed depending on the way SB was operationally defined and objectively measured.

METHODS

Sixty-three female participants aged 37.1 years (SD = 13.6) with a body mass index (BMI) of 29.6 kg/m² (SD = 4.7) had their body composition measured (BodPod, Concord, CA) then were continuously monitored for 5-7 days with the SenseWear Armband (SWA; sleep and activity intensity) and the activPAL (AP; posture). Data from both activity monitors were analysed separately and integrated resulting in a third measure of SB (activity intensity and posture; SED^INT). SB outputs were compared according to week or weekend day averages then correlated against body composition parameters after adjusting for moderate-to-vigorous physical activity (MVPA).

RESULTS

SED^SWA resulted in the most sedentary time 11.74 h/day (SD = 1.60), followed by SED^AP 10.16 h/day (SD = 1.75) and SED^INT 9.10 h/day (SD = 1.67). There was a significant positive association between SED^SWA and body mass [r(61) = 0.29, p = .02], BMI [r (61) = 0.33, p = .009] and fat mass [r(61) = 0.32, p = .01]. SED^AP and SED^INT were not associated with any of the indices of adiposity. Correlations between SB and adiposity were non-significant when controlling for MVPA.

CONCLUSIONS

The relationship between SB and adiposity differed depending on how SB was operationally defined and measured, and was dependent on MVPA. The definition of SB based on a sitting posture (SED^AP) was not strongly related to body fat, whereas the accumulation of any behaviour (sitting or standing) with an intensity of <1.5 METs (SED^SWA) (offset by the presence of MVPA) was positively associated with indices of adiposity. These data suggest that the postural element of SB (sitting) is not sufficient for the accumulation of adiposity, rather activities requiring low EE (<1.5 METs) and the absence of MVPA, regardless of posture, are associated with higher fat mass.

Screen-based sedentary behaviour and adiposity among school children: Results from International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) - Kenya

BACKGROUND

High levels of sedentary behaviours have been independently associated with several negative health indicators, including obesity. Screen time (ST) is often used as a contributing measure of sedentary time. It is recommended that children spend no more than 2 hours on recreational sedentary screen-based activities daily. We describe screen-based sedentary time of urban school children and examine the associations between body mass index (BMI) and percent Body Fat (%BF) with ST levels.

METHODS

Data were collected from 563 children aged 9 to 11 years attending 29 non-boarding primary schools in Nairobi, Kenya, as part of the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE). Data were analysed to test for associations between ST and sex, type of school attended (public verses private), Socioeconomic status, adiposity, and access to electronic devices. We also assessed participants' ST on school and weekend days.

RESULTS

Of the participants recruited, 15.5% had high ST levels, 67.9% spent no more than 2 hours in recreational screen activities on school days while 74.2% did not meet the guidelines on weekend days. Participants sex was associated with daily ST (t = 3.5, p<0.001), ST on the weekend (t = 3.9, p <0.001) and total ST per week (t = 3.5, p<0.001) with males having higher ST than females. ST was associated with type of school for daily ST (t = 3.6, p <0.001), ST on the weekend (t = 4.5, p<0.001) and total ST per week (t = 3.6, p<0.001) where private schools pupils had higher ST. ST was not associated with BMI. ST was not associated with %BF except on weekend days (p = 0.038) where those classified as overfat/obese (fat) had higher ST.

CONCLUSIONS

A large proportion of children spend more time than recommended on screen activities particularly on weekend days. Strategies to improve healthy living should focus on the reduction of sedentary ST for school-aged children.

Relationship between Physical Activity, Screen Time and Weight Status among Young Adolescents

It is well established that lack of physical activity and high bouts of sedentary behaviour are now associated with all-cause and cardiovascular mortality. The purpose of this study was to investigate the relationship between physical activity participation, overall screen time and weight status amongst early Irish adolescent youth. Participants were a sample of 169 students: 113 boys (mean age = 12.89 ± 0.34 years) and 56 girls (mean age = 12.87 ± 0.61 years). The data gathered in the present study included physical activity (accelerometry), screen time (self-report) and anthropometric measurements. Overweight and obese participants accumulated significantly more minutes of overall screen time daily compared to their normal-weight counterparts. A correlation between physical activity and daily television viewing was evident among girls. No significant interaction was apparent when examining daily physical activity and overall screen time in the prediction of early adolescents’ body mass index. Results suggest the importance of reducing screen time in the contribution towards a healthier weight status among adolescents. Furthermore, physical activity appears largely unrelated to overall screen time in predicting adolescent weight status, suggesting that these variables may be independent markers of health in youth. The existing relationship for girls between moderate-to-vigorous physical activity and time spent television viewing may be a potential area to consider for future intervention design with adolescent youth.

Reliability and validity of the Youth Leisure-time Sedentary Behavior Questionnaire (YLSBQ)

OBJECTIVES

To develop a questionnaire able to assess time spent by youth in a wide range of leisure-time sedentary behaviors (SB) and evaluate its test-retest reliability and criterion validity.

DESIGN

Cross-sectional observational.

METHODS

The reliability sample included 194 youth, aged 10-18 years, who completed the questionnaire twice, separated by one-week interval. The validity study comprised 1207 participants aged 8-18 years. Participants wore an accelerometer for 7 consecutive days. The questionnaire was designed to assess the amount of time spent in twelve different SB during weekdays and weekends, separately. In order to avoid usual phenomenon of time over reporting, values were adjusted to real available leisure-time (LT) for each participant. Reliability was assessed by using Intraclass Correlation Coefficients (ICC) and weighted (quadratic) kappa (k), and validity was assessed by using Pearson correlation and Bland-Altman plots.

RESULTS

The reliability of questionnaire showed a moderate-to-substantial agreement for the most (91%) of items (k=0.43-0.74; ICC=0.41-0.79) with three items (4%) reaching an almost perfect agreement (ICC=0.82-0.83). Only 'sitting and talking' evidenced fair-to-moderate reliability (k=0.27-0.39; ICC=0.34-0.46). The relationship between average sedentary time assessed by the questionnaire and accelerometry was moderate (r=0.36; p<0.001). Systematic biases were not found between questionnaire and accelerometer sedentary time for average day (r=0.05; p=0.11) but Bland-Altman plots suggest moderate discrepancies between both methods of SB measurement (mean=19.86; limits of agreement=-280.04 to 319.76).

CONCLUSIONS

The questionnaire showed moderate to good test-retest reliability and a moderate level of validity for assessing SB in youth, similar or slightly better to previously published in this population.

Parental Expectations and Child Screen and Academic Sedentary Behaviors in China

INTRODUCTION

This study examined sociodemographic patterns of parental expectations for academic performance, terminal degree, and future occupation for middle school students in China, and how these expectations influence students' screen-based and academic-related sedentary behaviors through parenting control practices.

METHODS

Based on data collected in 2013-2014 from 19,487 Chinese middle school students, bivariate logistic regressions tested associations between sociodemographic variables and parental expectations; structural equation models tested associations between parental expectations and students' self-reported daily time on TV/Internet/homework, with parental controls as potential mediators. Analyses were performed in October 2015.

RESULTS

Chinese students spent 0.96 (SD=1.44) hours/day on TV, 0.56 (SD=1.20) on Internet use, and 2.79 (SD=2.07) on homework. Girls spent more hours/day on homework (2.98 [SD=2.07] vs 2.62 [SD=2.04]) than boys but less on TV (0.90 [SD=1.37] vs 1.02 [SD=1.50]) and Internet (0.42 [SD=0.98] vs 0.69 [SD=1.36]). More than 30% of students were expected by parents to reach the top five of their class, almost 90% were expected to earn a college degree or higher, and >80% were expected to have a professional occupation. Students in rural areas, with siblings, and with lower parental SES tended to bear lower parental expectations. Children experiencing higher parental expectations spent more time on homework but less time on TV/Internet, partially explained by stricter parental homework and screen control.

CONCLUSIONS

High parental expectations suppress screen use but promote academic-related sedentary behaviors for Chinese children. Interventions should attend to academic-related sedentary behaviors and call for broader policies addressing sociocultural factors fueling high parental expectations.

Relationship between attention-deficit/hyperactivity disorder and sedentary behavior in adolescence: a cross-sectional study

Existing studies reveal that high levels of sedentary behavior are associated with more inattention and hyperactivity problems. Since most previous studies used screen time as an indicator of sedentary behavior and assessed symptoms of attention-deficit/hyperactivity disorder (ADHD) by short screening measures which do not allow to distinguish between subtypes of ADHD, the current study aimed to investigate association between different types of sedentary behavior and symptoms and subtypes of ADHD. The current cross-sectional study analyzed data of 913 students (46.1% girls) aged 13-17 years (M = 15.0, SD = 0.6). Using a self-administered questionnaire, screen-based and non-screen-based sedentary behavior and ADHD symptoms were assessed. Linear and logistic regression analyses were conducted. All analyses were adjusted for age, gender, moderate to vigorous physical activity and body mass index. Screen time was related to the total ADHD score (p < 0.001) as well as to the subscales inattention (p ≤ 0.016) and hyperactivity/impulsivity (p ≤ 0.008). Sedentary time without screens was virtually not associated with ADHD. As far as ADHD symptoms are considered as a correlate of sedentary behavior, the type of activity which is pursued sedentarily seems to matter: screen time, but not other non-screen-based sedentary activities should be considered as being a risk factor for ADHD.

Physical Activity and Pediatric Obesity: A Quantile Regression Analysis

PURPOSE

We aimed to determine whether moderate to vigorous physical activity (MVPA) and sedentary behavior (SB) were independently associated with body mass index (BMI) and waist circumference (WC) in children and adolescents.

METHODS

Data from the International Children's Accelerometry Database were used to address our objectives (N = 11,115; 6-18 yr; 51% female). We calculated age- and gender-specific BMI and WC z-scores and used accelerometry to estimate MVPA and total SB. Self-reported television viewing was used as a measure of leisure time SB. Quantile regression was used to analyze the data.

RESULTS

MVPA and total SB were associated with lower and higher BMI and WC z-scores, respectively. These associations were strongest at the higher percentiles of the z-score distributions. After including MVPA and total SB in the same model, the MVPA associations remained, but the SB associations were no longer present. For example, each additional hour per day of MVPA was not associated with BMI z-score at the 10th percentile (b = -0.02, P = 0.170) but was associated with lower BMI z-score at the 50th (b = -0.19, P < 0.001) and 90th percentiles (b = -0.41, P < 0.001). More television viewing was associated with higher BMI and WC, and the associations were strongest at the higher percentiles of the z-score distributions, with adjustment for MVPA and total SB.

CONCLUSIONS

Our observation of stronger associations at the higher percentiles indicates that increasing MVPA and decreasing television viewing at the population-level could shift the upper tails of the BMI and WC frequency distributions to lower values, thereby lowering the number of children and adolescents classified as obese.

Risk factors that affect metabolic health status in obese children

BACKGROUND

While some obese children are metabolically healthy (MHO), some have additional health problems, such as hypertension, dyslipidemia, insulin resistance, and hepatosteatosis, which increase mortality and morbidity related to cardiovascular diseases (CVD) during adulthood. These children are metabolically unhealthy obese (MUO) children. In this study we assessed the factors that affect metabolic health in obesity and the clinical and laboratory findings that distinguish between MHO and MUO children.

METHODS

In total, 1085 patients aged 6-18 years, with age- and sex-matched BMI exceeding the 95th percentile were included in the study (mean 11.1±2.9 years, 57.6% female, 59.7% pubertal). Patients without dyslipidemia, insulin resistance, hepatosteatosis, or hypertension were considered as MHO. Dyslipidemia was defined as total cholesterol level over 200 mg/dL, triglyceride over 150 mg/dL, LDL over 130 mg/dL, or HDL under 40 mg/dL. Insulin resistance was calculated using the homeostasis model of assesment for insulin resistance (HOMA-IR) index. Hepatosteatosis was evaluated with abdominal ultrasound. Duration of obesity, physical activity and nutritional habits, screen time, and parental obesity were questioned. Thyroid and liver function tests were performed.

RESULTS

Six hundred and forty-two cases (59.2%) were MUO. Older age, male sex, increased BMI-SDS, and sedentary lifestyle were associated with MUO. Excessive junk food consumption was associated with MUO particularly among the prepubertal obese patients.

CONCLUSIONS

Our results revealed that the most important factors that affect metabolic health in obesity are age and BMI. Positive effects of an active lifestyle and healthy eating habits are prominent in the prepubertal period and these habits should be formed earlier in life.

Prevalence of physical inactivity and its association on oral conditions in adolescents

BACKGROUND

The Brazilian population presents an ever-increasing number of sedentary people with poor oral health issues, including children and adolescents. Both physical inactivity and poor oral health have shown associations with various systemic diseases.

OBJECTIVE

The aim of this study was to verify the association between physical inactivity and oral health conditions.

SUBJECTS

Three hundred and fifty-three adolescents (mean age 13 and 17 years).

METHODS

An epidemiological cross-sectional study. Assessment of the presence of caries was made by using the decayed, missing, filled (DMF) index. Gingival bleeding and quality of oral hygiene were also examined to evaluate the oral conditions. The International Physical Activity Questionnaire (PAQ-C) was used to assess physical activity. The confidence parameter was set at p=0.05.

RESULTS

The results of this study showed that 74.3% were sedentary adolescents, the great majority of whom were girls (86.4%, p=0.001). There was a positive association between sedentary lifestyle and tooth decay (p=0.001), dental plaque (p=0.009), and time spent watching television (p=0.001).

CONCLUSION

This study concluded that there was a positive association between physical inactivity and poor oral health.

Investigating the influence of eating habits, body weight and television programme preferences on television viewing time and domestic computer usage

Background:

The present study explored the influence of eating habits, body weight and television programme preference on television viewing time and domestic computer usage, after adjusting for sociodemographic characteristics and home media environment indicators. In addition, potential substitution or complementarity in screen time was investigated.

Methods:

Individual level data were collected via questionnaires that were administered to a random sample of 2,946 Germans. The econometric analysis employed a seemingly unrelated bivariate ordered probit model to conjointly estimate television viewing time and time engaged in domestic computer usage.

Results:

Television viewing and domestic computer usage represent two independent behaviours in both genders and across all age groups. Dietary habits have a significant impact on television watching with less healthy food choices associated with increasing television viewing time. Body weight is found to be positively correlated with television screen time in both men and women, and overweight individuals have a higher propensity for heavy television viewing. Similar results were obtained for age groups where an increasing body mass index (BMI) in adults over 24 years old is more likely to be positively associated with a higher duration of television watching. With respect to dietary habits of domestic computer users, participants aged over 24 years of both genders seem to adopt more healthy dietary patterns. A downward trend in the BMI of domestic computer users was observed in women and adults aged 25–60 years. On the contrary, young domestic computer users 18–24 years old have a higher body weight than non-users. Television programme preferences also affect television screen time with clear differences to be observed between genders and across different age groups.

Conclusions:

In order to reduce total screen time, health interventions should target different types of screen viewing audiences separately.

Media device ownership and media use: Associations with sedentary time, physical activity and fitness in English youth

The aim of this study was to determine whether ownership and use of electronic media were associated with sedentary time and cardiorespiratory fitness (fitness) in youth. We also aimed to determine if associations were independent of physical activity (PA).

Fitness was measured using the 20 m shuttle-run. PA, sedentary time, ownership of media devices and media use were self-reported.

Participants (n = 678, age 10–15 years) reported daily sedentary time of 620 (± 210) min. Forty-one percent of participants had low PA and 50.4% had low fitness.

Higher weekend sedentary time was associated with low fitness in girls (p = 0.005) and boys (p < 0.001) and remained significant when adjusted for PA in the latter (p = 0.006). Using social media was associated with higher sedentary time in both sexes and low fitness in girls. High sedentary time was more likely (OR = 5.3, 95%CI: 2.0–14.4) in boys who owned game consoles. Low fitness was more likely in boys who owned digital/satellite TV receivers (OR = 1.8, 95%CI: 1.8–3.2).

Schoolchildren spent > 10 h or ~ 85% of each waking day sedentary. Use of social media was associated with higher sedentary time in both sexes and with low fitness in girls. Reducing social media use in youth offers one potential target for intervention. Behaviours associated with sedentary time differed from predictors of low fitness. The complex and often sex-specific interactions identified between sedentary time, PA and fitness suggest the need for carefully targeted interventions to reduce sedentary time and improve fitness in English youth.

•

English schoolchildren spend most of their waking time engaged in sedentary behaviours.

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Physical activity and sedentary time are independently associated with low fitness in boys.

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Owning a game console is associated with higher sedentary time in boys.

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Use of social media is associated with higher sedentary time in boys and girls.

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Owning a digital/satellite TV receiver doubles the risk of low cardiorespiratory fitness in boys.

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.

Individual and family environmental correlates of television and computer time in 10- to 12-year-old European children: the ENERGY-project

Background

The aim was to investigate which individual and family environmental factors are related to television and computer time separately in 10- to-12-year-old children within and across five European countries (Belgium, Germany, Greece, Hungary, Norway).

Methods

Data were used from the ENERGY-project. Children and one of their parents completed a questionnaire, including questions on screen time behaviours and related individual and family environmental factors. Family environmental factors included social, political, economic and physical environmental factors. Complete data were obtained from 2022 child–parent dyads (53.8 % girls, mean child age 11.2 ± 0.8 years; mean parental age 40.5 ± 5.1 years). To examine the association between individual and family environmental factors (i.e. independent variables) and television/computer time (i.e. dependent variables) in each country, multilevel regression analyses were performed using MLwiN 2.22, adjusting for children’s sex and age.

Results and discussion

In all countries, children reported more television and/or computer time, if children and their parents thought that the maximum recommended level for watching television and/or using the computer was higher and if children had a higher preference for television watching and/or computer use and a lower self-efficacy to control television watching and/or computer use. Most physical and economic environmental variables were not significantly associated with television or computer time. Slightly more individual factors were related to children’s computer time and more parental social environmental factors to children’s television time. We also found different correlates across countries: parental co-participation in television watching was significantly positively associated with children’s television time in all countries, except for Greece. A higher level of parental television and computer time was only associated with a higher level of children’s television and computer time in Hungary. Having rules regarding children’s television time was related to less television time in all countries, except for Belgium and Norway.

Conclusions

Most evidence was found for an association between screen time and individual and parental social environmental factors, which means that future interventions aiming to reduce screen time should focus on children’s individual beliefs and habits as well parental social factors. As we identified some different correlates for television and computer time and across countries, cross-European interventions could make small adaptations per specific screen time activity and lay different emphases per country.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2276-2) contains supplementary material, which is available to authorized users.

Relationship between lifestyle behaviors and obesity in children ages 9-11: Results from a 12-country study

OBJECTIVE

The aim was to assess associations between lifestyle behaviors and obesity in a multinational study of children from 12 countries representing a wide range of human development.

METHODS

The sample included 6,025 children 9-11 years of age. Behavioral risk factors included nocturnal sleep duration, moderate to vigorous physical activity (MVPA), television viewing (TV time), and healthy and unhealthy diet pattern scores. Multilevel analyses were used to obtain odds ratios for obesity expressed per standard deviation of each behavioral risk factor.

RESULTS

The odds ratios (95% confidence intervals) for obesity from multilevel, multivariable models were 0.79 (0.71-0.90) for nocturnal sleep duration, 0.52 (0.45-0.60) for MVPA, 1.15 (1.05-1.27) for TV time, 1.08 (0.96-1.20) for healthy diet score, and 0.93 (0.83-1.04) for unhealthy diet score in boys and 0.71 (0.63-0.80) for nocturnal sleep duration, 0.43 (0.35-0.53) for MVPA, 1.07 (0.96-1.19) for TV time, 1.05 (0.93-1.19) for healthy diet score, and 0.96 (0.82-1.11) for unhealthy diet score in girls.

CONCLUSIONS

Behavioral risk factors are important correlates of obesity in children, particularly low MVPA, short sleep duration, and high TV viewing.

Sedentary behavior and indicators of mental health in school-aged children and adolescents: A systematic review

OBJECTIVE

The presented systematic review aims at giving a comprehensive overview of studies assessing the relationship between sedentary behavior and indicators of mental health in school-aged children and adolescents.

METHODS

Six online databases (MEDLINE, EMBASE, PsycINFO, PsycARTICLES, CINAHL and SPORTDiscus) as well as personal libraries and reference lists of existing literature were searched for eligible studies.

RESULTS

Ninety-one studies met all inclusion criteria. There was strong evidence that high levels of screen time were associated with more hyperactivity/inattention problems and internalizing problems as well as with less psychological well-being and perceived quality of life. Concerning depressive symptoms, self-esteem, eating disorder symptoms, and anxiety symptoms, no clear conclusion could be drawn. But, taking quality assessment into account, self-esteem was negatively associated with sedentary behavior, i.e. high levels of time engaging in screen-based sedentary behavior were linked to lower scores in self-esteem.

CONCLUSIONS

Overall, the association between sedentary behavior and mental health indicators was rather indeterminate. Future studies of high quality and with an objective measure of sedentary behavior will be necessary to further examine this association as well as to investigate longitudinal relationships and the direction of causality. Furthermore, more studies are needed to identify moderating and mediating variables.

Correlates of Total Sedentary Time and Screen Time in 9-11 Year-Old Children around the World: The International Study of Childhood Obesity, Lifestyle and the Environment

Purpose

Previously, studies examining correlates of sedentary behavior have been limited by small sample size, restricted geographic area, and little socio-cultural variability. Further, few studies have examined correlates of total sedentary time (SED) and screen time (ST) in the same population. This study aimed to investigate correlates of SED and ST in children around the world.

Methods

The sample included 5,844 children (45.6% boys, mean age = 10.4 years) from study sites in Australia, Brazil, Canada, China, Colombia, Finland, India, Kenya, Portugal, South Africa, the United Kingdom, and the United States. Child- and parent-reported behavioral, household, and neighborhood characteristics and directly measured anthropometric and accelerometer data were obtained. Twenty-one potential correlates of SED and ST were examined using multilevel models, adjusting for sex, age, and highest parental education, with school and study site as random effects. Variables that were moderately associated with SED and/or ST in univariate analyses (p<0.10) were included in the final models. Variables that remained significant in the final models (p<0.05) were considered correlates of SED and/or ST.

Results

Children averaged 8.6 hours of daily SED, and 54.2% of children failed to meet ST guidelines. In all study sites, boys reported higher ST, were less likely to meet ST guidelines, and had higher BMI z-scores than girls. In 9 of 12 sites, girls engaged in significantly more SED than boys. Common correlates of higher SED and ST included poor weight status, not meeting physical activity guidelines, and having a TV or a computer in the bedroom.

Conclusions

In this global sample many common correlates of SED and ST were identified, some of which are easily modifiable (e.g., removing TV from the bedroom), and others that may require more intense behavioral interventions (e.g., increasing physical activity). Future work should incorporate these findings into the development of culturally meaningful public health messages.

Prospective associations between sedentary time, sleep duration and adiposity in adolescents

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We examined sedentary time and sleep length relative to changes in youth adiposity.

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Sedentary time was not associated with change in adiposity in either gender.

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Sleep duration was significantly inversely associated with adiposity gain in boys.

•

The association for sleep in boys was attenuated by physical activity and depression.

Objective

The objective of this study was to investigate whether objectively measured sedentary time and sleep duration are associated with changes in adiposity from mid- to late adolescence.

Methods

Students (n = 504, 42% boys) were recruited from schools in Cambridgeshire, UK. At baseline (mean age 15.0 ± 0.3 years), sedentary time was objectively measured by ≥3 days of combined heart rate and movement sensing. Concurrently, sleep duration was measured by combined sensing in conjunction with self-reported bed times. Fat mass index (FMI; kg/m²) was estimated at baseline and follow-up (17.5 ± 0.3 years) by anthropometry and bioelectrical impedance. FMI change (ΔFMI) was calculated by subtracting the baseline from follow-up values. Linear regression models adjusted for basic demographics, moderate-to-vigorous physical activity (MVPA), and depressive symptoms were used to investigate associations of sedentary time and sleep duration (mutually adjusted for one another) with ΔFMI.

Results

FMI increased by 0.5 and 0.6 kg/m² in boys and girls, respectively, but there was no association between sedentary time and ΔFMI in either gender (p ≥ 0.087), and no association between sleep duration and ΔFMI in girls (p ≥ 0.61). In boys, each additional hour of baseline sleep significantly reduced the ΔFMI by 0.13 kg/m² (p = 0.049), but there was little evidence for this association after adjusting for MVPA and depressive symptoms (p = 0.15).

Conclusions

Sedentary time may not determine changes in adiposity from mid- to late adolescence, nor may sleep duration in girls. However, sleep length may be inversely associated with adiposity gain in boys, depending on whether the relationship is confounded or mediated by MVPA and depression.

Correlates of objectively measured sedentary time and self-reported screen time in Canadian children

BACKGROUND

Demographic, family, and home characteristics play an important role in determining childhood sedentary behaviour. The objective of this paper was to identify correlates of total sedentary time (SED) and correlates of self-reported screen time (ST) in Canadian children.

METHODS

Child- and parent-reported household, socio-demographic, behavioural, and diet related data were collected; directly measured anthropometric and accelerometer data were also collected for each child. Participants with complete demographic, anthropometric, and either SED (n=524, 41% boys) or ST (n=567, 42% boys) data from the Canadian site of the International Study of Childhood Obesity Lifestyle and the Environment (ISCOLE) were included in analysis. Sixteen potential correlates of SED and ST were examined using multilevel general linear models, adjusting for sex, ethnicity, number of siblings, and socio-economic status. All explanatory variables moderately associated (p<0.10) with SED and/or ST in univariate analyses were included in the final, fully-adjusted models. Variables that remained significant in the final models (p<0.05) were considered correlates of SED and/or ST.

RESULTS

Children averaged 8.5 hours of daily SED; no differences in total SED, or total ST were seen between girls and boys, but boys reported significantly more video game/computer usage than girls. Boys also had higher waist circumference and BMI z-scores than girls. In the final models, waist circumference and number of TVs in the home were the only common correlates of both SED and ST. SED was also negatively associated with sleep duration. ST was also positively associated with mother's weight status, father's education, and unhealthy eating pattern score and negatively associated with healthy eating pattern score, and weekend breakfast consumption. Few common correlates existed between boys and girls.

CONCLUSION

Several factors were identified as correlates of SED and/or of ST in Canadian children; however, few correlates were common for both SED and ST, and for both boys and girls. This suggests that a single strategy to reduce SED and ST is unlikely to be effective. Future work should examine a variety of other, non-screen based sedentary behaviours and their potential correlates in the hopes of creating tailored public health messages to reduce SED and ST in both boys, and girls.

Longitudinal levels and bouts of objectively measured sedentary time among young Australian children in the HAPPY study

OBJECTIVES

To examine differences in sedentary time and bouts during and outside of childcare/school periods, and changes in sedentary time and bouts over 1-year among children who remained in childcare (childcare subsample) and among those who transitioned to school (school transition subsample).

DESIGN

Longitudinal study.

METHODS

Results are based on 177 children aged 3-5 years at baseline from the Healthy Active Preschool and Primary Years study in Melbourne, Australia. Sedentary time and sedentary bouts (1-4, 5-9, ≥10min) for total days and during/outside of childcare/school on weekdays were accelerometer-derived at baseline (2008) and 1-year follow-up (2009), when 57% of participants had transitioned to school. Repeated-measures ANCOVAs adjusting for wear time were conducted.

RESULTS

Compared to the outside of childcare/school period, children in the school transition subsample spent more time (0.5min/day or 0.9% wear time) in ≥10min sedentary bouts at baseline, participated in 26 more min/day of sedentary time at follow-up, and all participants spent less time (2-16min/day or 2-3% of wear time) in 5-9min sedentary bouts at baseline and follow-up during the childcare/school period (P<0.05). Increases in sedentary time (34-54min/day or 2-3% wear time) and time spent in 1-4min sedentary bouts (18-29min/day or 1-2% of wear time) were observed from baseline to follow-up in both the total sample and school transition sub-sample, for total days and during the childcare/school period (P<0.05).

CONCLUSIONS

School transition was marked by increased sedentary time. School practices, policies, and environments to reduce sedentary time should be explored.

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.

Metabolic risk and television time in adolescent females

OBJECTIVES

A sedentary lifestyle is increasingly implicated in a negative metabolic health profile among youth. The present study examined relationships between clustered metabolic risk factors and TV viewing in female adolescents.

METHODS

The sample comprised 262 girls 14-17 years. Height, weight, fasting glucose, insulin, HDL cholesterol, triglycerides, and blood pressure were measured. Body mass index (BMI) was calculated. TV viewing time and moderate-to-vigorous physical activity (MVPA) were estimated from a 3-day diary. Outcome variables were normalized and expressed as Z scores which were summed into a metabolic risk score. Multiple linear regression analysis was used.

RESULTS

TV viewing was independently associated with increased prevalence of clustered metabolic risk in girls after adjustment for several confounders (i.e., chronological age, BMI, MVPA, and parental education). The final model also indicated that lower levels of MVPA, higher BMI, and lower mother education were associated with higher metabolic risk.

CONCLUSIONS

Increased TV viewing had an adverse effect on metabolic health of adolescent girls. The findings highlight the potential importance of preventive actions to ameliorate metabolic risk in youth which target both sedentary and physically active behaviors.

Physical activity and sedentary behaviour in European children: the IDEFICS study

OBJECTIVE

To estimate the prevalence of physical activity and sedentary behaviours in European children, and to evaluate the relationship between media availability in personal space and physical activity in relation to total screen time.

DESIGN

Data from the baseline IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) cross-sectional survey. Information on hours of television/digital video disk/video viewing and computer/games-console use (weekday and weekend days), media device availability in personal space, sports club membership, hours of active organized play and commuting (to and from school) were assessed via a self-reported parental questionnaire. Total screen time was defined as the sum of daily media use and subsequently dichotomized into meeting or not meeting the guidelines of the American Academy of Pediatrics.

SETTING

Eight survey centres (Italy, Estonia, Cyprus, Belgium, Sweden, Germany, Hungary and Spain).

SUBJECTS

Children (n 15 330; 51% males) aged 2-10 years.

RESULTS

Percentage of children engaged in total screen time for >2 h/d was higher on weekend days (52% v. 20% on weekdays) and in the older group (71% in males; 57% in females), varying by country. Children with a television set in their bedroom were more likely not to meet the screen time recommendations (OR = 1·54; 95% CI 1·60, 1·74).

CONCLUSIONS

Approximately a third of the children failed to meet current screen time recommendations. Availability of a television set in personal space increased the risk of excess total screen time. This information could be used to identify potential targets for public health promotion actions of young population groups.

Sedentary behaviour as an emerging risk factor for cardiometabolic diseases in children and youth

Sedentary behaviour (e.g. TV viewing, seated video game playing, prolonged sitting) has recently emerged as a distinct risk factor for cardiometabolic diseases in children and youth. This narrative review provides an overview of recent evidence in this area and highlights research gaps. Current evidence suggests that North American children and youth spend between 40% and 60% of their waking hours engaging in sedentary pursuits. Although data are lacking concerning temporal trends of objectively measured sedentary time, self-reported sedentary behaviours have increased over the past half century, with a rapid increase since the late 1990s. Excessive sedentary behaviour has been found to have independent and deleterious associations with markers of adiposity and cardiometabolic disease risk. These associations are especially consistent for screen-based sedentary behaviours (TV viewing, computer games, etc), with more conflicting findings observed for overall sedentary time. The above associations are possibly mediated by the influence of screen-based sedentary behaviours on energy intake. Although excessive sitting has been reported to have adverse acute and chronic metabolic impacts in adults, research on children is lacking. Research is particularly needed to investigate the impact of characteristics of sedentary behaviour (i.e. type/context, sedentary bout length, breaks in sedentary time, etc), as well as interventions that examine the health and behavioural impacts of sitting per se.