Descriptive epidemiology of screen and non-screen sedentary time in adolescents: a cross sectional study

The Association Between Socioeconomic Status and Use of Time in Australian Children and Adolescents

PURPOSE

There are well-known socioeconomic status (SES) gradients in children and adolescents' health which may be associated with time use. Our aim was to evaluate the association between Australian children's 24-hour time use and SES using four separate surveys from 2005 to 2021.

METHODS

Time use was assessed in 4526 8-19-year-olds from the 2005 Health of Young Victorians, 2007 National Children's Nutrition and Physical Activity, 2015 Child Health CheckPoint, and 2019-21 Life on Holidays study. Each survey used the same reliable, valid, 24-hour recall instrument. SES was quantified using tertiles of household income, education, and postcode-level measures. Compositional data analysis was used to compare 24-hour time use between SES categories, adjusting for age, sex, and puberty.

RESULTS

Time-use compositions differed significantly by SES in each survey. Relative to the lowest SES, children from the highest SES accumulated on average 31 min/day more School-related time, 6 min/day more Passive Transport and 6 min/day more Self-care. Conversely, they accumulated 30 min/day less Screen Time (which included computer time), 11 min/day less sleep, and spent 7 min/day less in Domestic/Social activities. There were only small differences in Quiet Time and Physical Activity.

DISCUSSION

SES-related differences in time use were robust across ages 8-19, a 16-year timespan, diverse Australian geographical regions, and using different SES metrics. The exchange of about 30 min/day between School-related activities and Screen Time amounts to >180 hours extra exposure to School-related activities annually in the highest SES category relative to the lowest, equivalent to >6 weeks of school time per year.

Decreasing Sedentary Behaviors in Youth to Prevent and Manage Childhood Obesity: Is It Realistic?

PURPOSE OF REVIEW

Decreasing sedentary behaviors has been proposed as one approach to reduce the rate of obesity in youth. This review summarizes the contemporary literature examining the efficacy of these interventions in the school and community along with an additional focus on the role of socioeconomic status in these interventions.

RECENT FINDINGS

Studies that focus on decreasing sedentary behavior have utilized a wide variety of strategies in a number of settings. The effects of these interventions are often hindered by non-standard outcome measures, study infidelity, and subjective measures of sedentary time. However, interventions that incorporate engaged stakeholders and include younger subjects appear to be the most likely to succeed. Promising interventions to decrease sedentary behaviors have been shown in recent clinical trials; however, replicating and sustaining these results is challenging. From the available literature, school-based interventions have the potential of reaching the largest group of children. In contrast, interventions in younger children, particularly those with invested parents, seem to be the most effective.

Association of screen time and physical activity with health-related quality of life in college students

OBJECTIVE

To determine the association between screen time and physical activity with quality of life among Chilean university students.

METHODS

Cross-sectional and analytical study conducted on 726 first-year university students who replied three questionnaires: Youth Risk Behavior Survey, WHO Quality of Life-BREF scale, and the International Physical Activity Questionnaire.

RESULTS

There were differences in overall quality of life (p < .001) and level of satisfaction in health (p < .01) according to screen exposure time. These results follow a linear trend for all the quality of life domains (p < .01), and they indicate that there is an inverse association between screen time and quality of life.

CONCLUSION

There is an inverse association between screen time and quality of life in university students. Students with a longer screen exposure time showed a lower quality of life, specifically in the domains of social relationships and psychological health, regardless of sex, physical activity, or socioeconomic level.

Associations between meeting 24-hour movement guidelines and academic achievement in Australian primary school-aged children

BACKGROUND

Few studies have investigated associations between academic achievement and meeting recommendations from the 24-hour (24-h) movement guidelines. The specific guidelines associated with the most benefit academic achievement are unknown. Utilizing both self-report and objective movement data, this study examined associations between academic achievement and meeting individual recommendations and combinations of recommendations from the 24-h movement guidelines (sleep, physical activity, and screen time).

METHODS

Data from CheckPoint, a cross-sectional study nested between Waves 6 and 7 of the Longitudinal Study of Australian Children, were used. Movement behaviors were measured using 24-h wrist-worn accelerometry (GENEActiv (Activinsights, Kimbolton, UK)) and were self-reported by children using the Multimedia Activity Recall for Children and Adolescents. Academic achievement was measured using a nationally administered standardized test in literacy and numeracy. Analysis of covariance, with t tests with sequential Bonferroni adjustments, was used to compare academic achievement with all possible combinations of meeting recommendations, adjusting for demographic confounders. Two models were considered: guideline compliance assessed by self-report (n = 1270, mean age = 11.99 years, 52% males) and by accelerometry (for moderate-to-vigorous intensity physical activity (MVPA) and sleep)) and self-report (screen time) in combination (n = 927, mean age = 11.97 years, 52% males).

RESULTS

Literacy achievement significantly differed based on self-report (F_{(7, 1258)} = 3.08, p = 0.003) and accelerometer derived (F_{(7, 915)} = 2.40, p = 0.02) guideline compliance. Numeracy achievement significantly differed based on self-report (F_{(7, 1258)} = 2.92, p = 0.005) but not accelerometer derived guideline compliance (F_{(7, 915)} = 0.80, p = 0.58). When assessed by self-report, children who met all guidelines (t₍₃₃₄₎ = -4.05, p = 0.0001) or met the screen time and sleep guidelines in combination (t₍₁₂₅₎ = -5.02, p < 0.001) had superior literacy achievement. Meeting the self-report MVPA guideline in any combination was associated with higher numeracy scores (p < 0.05). Post-hoc analyses showed no differences in academic achievement for any category of accelerometer derived guideline compliance.

CONCLUSION

The findings suggest that limiting recreational screen time is important for literacy achievement and that encouraging compliance with the MVPA guideline is important for numeracy achievement.

Intrapersonal, interpersonal and environmental correlates of moderate to vigorous physical activity and sedentary time in adolescents with intellectual and developmental disabilities

BACKGROUND

Although correlates of physical activity (PA) have been extensively examined in both children and adolescents who are typically developing, little is known about correlates of moderate to vigorous physical activity (MVPA) and sedentary time in adolescents with intellectual and developmental disabilities (IDD). Therefore, we examined intrapersonal, interpersonal and environmental factors and their association with device-based MVPA and sedentary time in adolescents with IDD.

METHODS

MVPA and sedentary time was assessed using a hip-worn ActiGraph model wGT3x-BT tri-axial accelerometer across a 7-day period in adolescents with IDD and one of their parents. Pearson and point-biserial correlations were calculated to inspect the associations of PA (MVPA, sedentary time) with intrapersonal factors (demographic characteristic, BMI, waist circumference, motor ability, muscle strength, grip strength, cardiovascular fitness and self-efficacy for PA), interpersonal factors (parent demographics, parent BMI, parent MVPA and sedentary time, family social support for PA, parent barriers and support for PA, parent's beliefs/attitudes towards PA and number of siblings), and environmental factors (meteorologic season and COVID-19). Ordinary least squares regression was used to estimate the unique contributions of key factors to PA after controlling for participants' age, sex, race, waist circumference and total wear time.

RESULTS

Ninety-two adolescents (15.5 ± 3.0 years old, 21.7% non-White, 6.5% Hispanic, 56.5% female) provided valid accelerometer data. Average sedentary time was 494.6 ± 136.4 min/day and average MVPA was 19.8 ± 24.2 min/day. Age (r = 0.27, P = 0.01), diagnosis of congenital heart disease (r = -0.26, P = 0.01) and parent sedentary time (r = 0.30, P = 0.01) were correlated with sedentary time. BMI (r = -0.24, P = 0.03), waist circumference (r = -0.28, P = 0.01), identifying as White (r = -0.23, P = 0.03) and parent MVPA (r = 0.56, P < 0.001) were correlated with MVPA. After adjusting for the adolescent's age, sex, race, waist circumference, and total wear time, the association between parent and adolescent MVPA remained significant (b = 0.55, P < 0.01, partial η2  = 0.11).

CONCLUSION

The results of this study provide evidence that race, waist circumference and parental MVPA may influence the amount of MVPA in adolescents with IDD. The limited available information and the potential health benefits of increased MVPA highlight the need to evaluate the effectiveness of multi-component interventions targeting both intrapersonal and interpersonal levels to promote increased PA in adolescents with IDD.

Physical activity and sedentary behaviour of female adolescents in Indonesia: A multi-method study on duration, pattern and context

Background/Objective

Exploring comprehensive information on the duration, pattern and context of physical activity and sedentary behaviour is important to develop effective policies and interventions. Especially in lower- and middle-income countries, our understanding of these health-behaviours is limited. Our study aimed to investigate physical activity and sedentary behaviour of female Indonesian adolescents by using a multi-method approach.

Methods

Female adolescents (n = 5; 13–15 years old) from Yogyakarta, Indonesia wore accelerometers and automated wearable cameras for four days, and completed diaries, and interviews between February and March 2020.

Results

Participants’ activity, especially on non-school days, was dominated by light-intensity physical activity. Four of the 5 participants did not meet the physical activity guidelines. Participants spent a great proportion of time on screen-based sedentary behaviour (school days: 83.2% of wear time; non-school days: 75.7% of wear time). During school days, most physical activity and sedentary behaviour was done at school. Screen time was mainly done on the school day evenings and weekend mornings. Participants mostly used smartphones in the bedroom and living room in a solitary environment. Interviews suggest that the high amount of screen time seemed to be influenced by a lack of awareness of current guidelines, the feeling of urgency to check information, and the lack of parental supervision. Non-screen-based sedentary behaviour comprised just over 10% of total camera images.

Conclusion

The use of a multi-method approach facilitated a rich understanding of the duration, patterns, and contexts of physical activity and sedentary behaviour in participants. Future studies might consider using similar methods in a larger sample.

On the issue of continuity in the formation of universal competencies among school graduates and university students

In recent years, the issues of preserving the health of the population and prevention of certain diseases leading to a significant deterioration in the life quality and human activity have been keenly discussed all over the world. This circumstance has significantly activated the scientific research in development and testing of educational programs, which are based on the development of the need for systematic independent physical exercises that contribute to the formation of general cultural competencies among students of educational institutions. At the same time, the level of formation of this knowledge, skills and abilities should contribute to the further continuous process of formation of universal competencies in physical culture and sports of university students. This paper aims to analyze and experimentally substantiate the need for continuity in the formation of universal competencies among schoolchildren and university students in physical culture, as the basis for successful professionally applied physical training of future specialists in various fields of economics. The conducted research shows the need to improve the organizational and content provision of physical culture in general education institutions to increase the effectiveness of organized physical culture classes, and to improve the quality of the formation of general cultural competencies (knowledge, skills, abilities).

The association between screen time and reported depressive symptoms among adolescents in Sweden

BACKGROUND

How screen use is associated with adolescents' mental health has been widely debated in public media during the last decade, but there is still lack of information about if and how the associations vary between types of electronic media.

OBJECTIVE

This study aimed to examine how time spent on types of screen use (social media, gaming alone, gaming in groups and watching TV) was associated with depressive symptoms among adolescents in Sweden, and whether gender moderated these associations.

METHODS

We analysed data from the Swedish section of the Children of Immigrants: Longitudinal Survey in Four European Countries. The final sample consisted of 3556 eighth grade adolescents in 2011 (51% girls). We used logistic regression analysis to estimate the odds ratio of feeling depressed often versus less often/not at all using time spent on different types of screen use as predictor variables. Additionally, we tested interaction effects between gender and the predictor variables.

RESULTS

Our results showed that spending more than 2 hours on social media was associated with higher odds of feeling depressed often compared with spending 2 hours or less. Not watching TV was associated with higher odds of feeling depressed often compared with watching TV. These patterns did not differ across genders. Gaming alone and gaming in groups were not associated with depressive symptoms.

CONCLUSIONS

Our findings suggest that more frequent social media use and not watching TV were associated with a higher level of depressive symptoms.

A dual process model to predict adolescents' screen time and physical activity

OBJECTIVE

Many adolescents report a lack of physical activity (PA) and excess screen time (ST). Psychological theories aiming to understand these behaviours typically focus on predictors of only one behaviour. Yet, behaviour enactment is often a choice between options. This study sought to examine predictors of PA and ST in a single model. Variables were drawn from dual process models, which portray behaviour as the outcome of deliberative and automatic processes.

DESIGN

411 Finnish vocational school students (age 17-19) completed a survey, comprising variables from the Reasoned Action Approach (RAA) and automaticity pertaining to PA and ST, and self-reported PA and ST four weeks later.

MAIN OUTCOME MEASURES

Self-reported time spent on PA and ST and their predictors.

RESULTS

PA and ST correlated negatively (r = -.17, p = .03). Structural equation modelling revealed that intentions and habit for PA predicted PA while ST was predicted by intentions and habit for ST and negatively by PA intentions. RAA-cognitions predicted intentions.

CONCLUSION

PA and ST and their psychological predictors seem to be weakly interlinked. Future studies should assess more behaviours and related psychological influences to get a better picture of connections between different behaviours.

HighlightsPhysical activity and screen time are largely mutually exclusive classes of behaviours and might therefore be related in terms of their psychological predictors.411 adolescent vocational school students self-reported variables from the Reasoned Action Approach and behavioural automaticity related to physical activity and leisure time screen time behaviours as well as those behaviours.Structural equation modelling revealed expected within-behaviour predictions but, against expectations, no strong connections between the two behaviour classes in terms of their predictors. Only intentions to engage in physical activity negatively predicted screen time.Future research should aim to measure a wider range of mutually exclusive classes of behaviours that cover a large share of the day to uncover relations between behaviours and their respective predictors.

Age-varying Bi-directional Associations Between Momentary Affect and Movement Behaviors in Children: Evidence From a Multi-wave Ecological Momentary Assessment Study

BACKGROUND

The bi-directional associations between affective states and movement behaviors (e.g., physical activity, sedentary behavior) have been observed in children. It is unclear if the strength of these bi-directional associations varies with age as children transition from childhood to adolescence.

PURPOSE

This multi-wave ecological momentary assessment (EMA) study investigates the acute time-varying associations between affect and movement behaviors among youth.

METHODS

Children (N = 195, baseline mean age = 10.72, range = 8-12 years, mean BMI-z = 0.49, 51% female) participated in a six-wave EMA study across three years. Each EMA survey captured momentary positive and negative affect. Time spent in moderate-to-vigorous physical activity (MVPA) and sedentary time in the 15-min window before and after each EMA survey was calculated using accelerometry data. Time-varying effect models (TVEM) examined the acute bi-directional associations between momentary positive/negative affect and MVPA/sedentary time across ages 8 to 14.

RESULTS

Children provided 14,246 valid activity-matched EMA surveys across all waves. TVEM plots revealed that the directionality and the strength (time-varying slopes) of associations between momentary affect and activity levels vary across ages. Positive affect was associated with higher MVPA levels and lower sedentary time at younger ages, whereas negative affect linked to lower MVPA levels and more sedentary time at older ages.

CONCLUSIONS

The acute associations between momentary affect and (in)activity levels may vary as a function of children's age. Applying TVEM to intensive longitudinal data could provide valuable information for developing age-tailored interventions that promote healthy lifestyles among children and adolescents.

Concurrent screen use and cross-sectional association with lifestyle behaviours and psychosocial health in adolescent females

Aim:

To describe concurrent screen use and any relationships with lifestyle behaviours and psychosocial health.

Methods:

Participants wore an accelerometer for seven days to calculate physical activity sleep and sedentary time. Screen ownership and use and psychosocial variables were self-reported. Body mass index (BMI) was measured. Relationships were explored using mixed models accounting for school clustering and confounders.

Results:

In 816 adolescent females (age: 12.8 SD 0.8 years; 20.4% non-white European) use of ≥2 screens concurrently was: 59% after school, 65% in evenings, 36% in bed and 68% at weekends. Compared to no screens those using: ≥1 screens at weekends had lower physical activity; ≥2 screens at the weekend or one/two screen at bed had lower weekend moderate-to-vigorous physical activity; one screen in the evening had lower moderate-to-vigorous physical activity in the after-school and evening period; ≥1 screens after school had higher BMI; and ≥3 screens at the weekend had higher weekend sedentary time. Compared to no screens those using: 1–3 after-school screens had shorter weekday sleep; ≥1 screens after-school had lower time in bed.

Conclusion:

Screen use is linked to lower physical activity, higher BMI and less sleep. These results can inform screen use guidelines.

The Associated Factors of Prolonged Screen Time and Using Electronic Devices before Sleep among Elderly People in Shaanxi Province of China: A Cross-Sectional Study

This study aimed to investigate prolonged screen time and using electronic devices before sleep and their associated factors in elderly people in Shaanxi province of China. We conducted a cross-sectional study among 2647 elderly participants aged 60-88 years. Data were collected through questionnaires. Demographic characteristics, screen time, using electronic devices before sleep, health status, lifestyles, sleep quality, and other associated factors were investigated. Logistic regression analysis was used to analyze the relationship between the associated factors of screen time and using electronic devices before sleep. The crude odds ratio (cOR) and adjusted odds ratio (aOR) and their 95% confidence intervals (CI) were calculated. A total of 1784 subjects completed the questionnaire. There were 6.89% participants with prolonged screen time and 13.45% using electronic devices before sleep frequently. Prolonged screen time was associated with personal monthly income (aOR = 1.205, p = 0.001), number of household residents (aOR = 0.860, p = 0.010), rural residents (aOR = 0.617, p = 0.038), and regular drinkers (aOR = 2.889, p < 0.001). Using electronic devices before sleep was associated with being female (aOR = 0.657, p = 0.007), family monthly income (aOR = 0.866, p = 0.002), being an occasional drinker (aOR = 1.891, p = 0.005), and self-reported sleep quality (aOR = 1.593, p = 0.007). In conclusion, several factors related to screen time or using electronic devices before sleep were identified. Only being a drinker was a common associated factor for both screen time and using electronic devices before sleep.

Prospective Associations between Maternal and Child Diet Quality and Sedentary Behaviors

As the most likely primary caregivers, mothers are an integral part of children’s social influence and are therefore greatly involved in shaping their children’s behaviors. The objectives were to determine the prospective associations between maternal and child diet quality and sedentary behaviors. This study, within the framework of a community-based intervention study, included 1130 children aged 8–10 years and their mothers. The study was carried out during two academic years (2012/2014) with a mean follow-up of 15 months. Exposure and outcome variables were measured at baseline and follow-up, respectively. Diet quality was assessed by the KIDMED questionnaire and the short Diet Quality Screener, respectively. Sedentary behaviors were determined by standardized questions of sedentary behaviors. Maternal consumption of fruits, vegetables, fish, legumes, pasta/rice, dairy products, nuts and baked goods were positively associated (p < 0.05) with the corresponding child behavior. Multiple linear regression models adjusted for sex, age, maternal education and intervention group revealed significant cross-sectional (p < 0.005) and prospective (p < 0.01) associations between maternal and child overall diet quality and sedentary behaviors. Maternal diet quality and sedentary behaviors were predictive for these lifestyle behaviors in children.

Adolescent Technology, Sleep, and Physical Activity Time in Two US Cohorts

The advent of internet-enabled mobile digital devices has transformed US adolescent technology use over the last decade, yet little is known about how these changes map onto other health-related behaviors. We provide a national profile of how contemporary technology use fits into adolescents' daily health lifestyles compared to the previous generation, with particular attention to whether and for whom technology use displaces time spent in sleep or physical activity. Time diaries were collected from 11-17 year olds in 2002-03 (N=1,139) and 2014-16 (N=527) through the US Panel Study of Income Dynamics Child Development Supplement. Contemporary adolescents spent 40 minutes more per week in technology-focused activities, but their composition was more varied compared to the earlier cohort. Contemporary technology use was predictive of less time in physical activity, and adolescents engaged in frequent video game play spent less time in physical activity compared to peers with other technology use profiles.

The Effect of Season and Neighbourhood-Built Environment on Home Area Sedentary Behaviour in 9-14 Year Old Children

There is little understanding of how the built environment shapes activity behaviours in children over different seasons. This study sought to establish how seasonal weather patterns, in a given year in a mid-western Canadian city, affect sedentary time (SED) in youth and how the relationship between season and SED are moderated by the built environment in their home neighbourhood. Families with children aged 9-14 years were recruited from the prairie city of Saskatoon, Canada. Location-specific, device-based SED was captured in children during three timeframes over a one-year period using GPS-paired accelerometers. Multilevel models are presented. Children accumulated significantly greater levels of SED in spring but significantly less SED in the fall months in comparison to the winter months. Children living in neighbourhoods with the highest density of destinations accumulated significantly less SED while in their home area in comparison to their counterparts, and this effect was more pronounced in the spring and summer months. On weekends, the rise in sedentariness within the home area was completely diminished in children living in neighbourhoods with the greatest number of destinations and highest activity friendliness. These results suggested that increasing neighbourhood amenities can lead to a reduced sedentariness of youth, though more so in the warmers months of the year.

Adherence to 24-Hour Movement Guidelines among Spanish Adolescents: Differences between Boys and Girls

Background: The 24-Hour Movement Guidelines for adolescents recommend ≥60 min/day of moderate-to-vigorous physical activity (PA), ≤ 2 h/day of screen time, and 8–10 h/day of sleep. Since little information is available on the 24-Hour Movement Guidelines in Spanish adolescents, this study aims to estimate the proportion of Spanish adolescents meeting individual and combinations of these 24-Hour Movement Guidelines. Moreover, another aim of this study is to examine gender differences in compliance with 24-Hour Movement Guidelines. Methods: A final sample of 1465 Spanish adolescents (44.50% girls; 13.08 ± 0.86) participated in this cross-sectional study. The 24-Hour Movement Guidelines were measured during weekdays and the weekend days by self-reported questionnaires. Results: Although most adolescents met sleep duration guidelines (81.3%), only 38% and 15.8% met physical activity and screen time guidelines, respectively. Only 5.4% of these adolescents met all three 24-Hour Movement Guidelines, whereas 10.2% of this sample did not meet any of these guidelines. Although boys reported greater compliance with physical activity recommendations and girls with screen time recommendations, no significant gender differences were found in the compliance of all three 24-Hour Movement Guidelines. Conclusion: Given that 94.4% of Spanish adolescents did not meet 24-Hour Movement Guidelines, promoting all these three movement behaviours in both boys and girls is an urgent public health priority.

Prevalence of low back pain in young Brazilians and associated factors: Sex, physical activity, sedentary behavior, sleep and body mass index

BACKGROUND

Low back pain (LBP) has become increasingly common, but the prevalence of this complaint and associated factors in young people remains controversial.

OBJECTIVE

This study aimed to identify the prevalence of LBP and to explore the existence of associated factors (sex, physical activity, sedentary lifestyle, sleep, body mass index and waist circumference).

METHODS

This study considered all complaints of the lumbar region (acute or chronic) as LBP, which can irradiate to the backside and legs, lasting a minimum of 24 hours. Youngsters aged 15 to 18 years from a school in the south of Brazil were evaluated. Descriptive statistics was used, in particular Chi-square, Mann-Whitney U tests and binary logistic regression. A significance level of p< 0.05 was adopted.

RESULTS

A total of 330 youngsters answered a questionnaire and had their anthropometric measurements measured (response rate 84%). The prevalence of LBP in the present was 30%, quarterly 63% and throughout life 77%. There was a significant association between LBP and sex: girls have an increased risk of LBP in the last three-month period (PR = 1.3, 95% CI 1.06-1.56) and throughout life (PR = 1.2, 95% CI 1.04-1.43). The practice of physical activities was also associated with LBP, but as a protection factor in the present and in the last three-month period (PR = 0.7, 95% CI 0.47-0.90). Physical education at school has demonstrated a protective factor regarding LBP throughout life (PR = 0.9, 95% CI 0.77-0.97). Most of the students did not comply with recommendations related to sleep and time spent doing activities in front of a screen, and no association of these factors with LBP was detected. This exposure (physical activity, sleep time, sedentarism) did not present significant association with LBP when adjusted by the confusion factors (sex, age, BMI).

CONCLUSIONS

Youngsters reported a high prevalence of LBP. Girls were at greater risk of LBP than boys. It is recommended that prevention strategies focus on the practices of physical activities and scholar physical education. No association of LBP with sedentary lifestyle (TV and computer use time, sleep time), anthropometric measures and sleeping duration was observed.

How do short sleepers use extra waking hours? A compositional analysis of 24-h time-use patterns among children and adolescents

BACKGROUND

To examine compositional associations between short sleep duration and sedentary behavior (SB), light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) among children and adolescents.

METHODS

Multi-day 24-h data on sleep, SB, LPA and MVPA were collected using accelerometers among 343 children (8-13 years old) and 316 adolescents (14-18 years old). Children and adolescents with sleep duration of < 9 and < 8 h, respectively, were classified as short sleepers. Robust compositional regression analysis was used to examine the associations between short sleep duration and the waking-time composition.

RESULTS

Seventy-one percent of children and 75.3% of adolescents were classified as short sleepers. In children, being a short sleeper was associated with higher SB by 95 min/day (p < 0.001) and lower MVPA by 16 min/day (p = 0.002). Specifically, it was associated with a higher amount of time spent in long sedentary bouts (β_ilr1 = 0.46, 95% confidence interval [CI] = 0.29 to 0.62) and lower amounts of time spent in sporadic SB (β_ilr1 = - 0.17, 95% CI = -0.24 to - 0.10), sporadic LPA (β_ilr1 = - 0.09, 95% CI = -0.14 to - 0.04) and sporadic MVPA (β_ilr1 = - 0.17, 95% CI = -0.25 to - 0.10, p < 0.001 for all), relative to the remaining behaviours. In adolescents, being a short sleeper was associated with a higher amount of time spent in SB by 67 min/day (p = 0.001) and lower LPA by 2 min/day (p = 0.035). Specifically, it was associated with more time spent in sedentary bouts of 1-9 min (β_ilr1 = 0.08, 95% CI = 0.02 to 0.14, p = 0.007) and 10-29 min (β_ilr1 = 0.10, 95% CI = 0.02 to 0.18, p = 0.015), relative to the remaining behaviours.

CONCLUSIONS

Among children and adolescents, short sleep duration seems to be highly prevalent and associated with less healthy waking time. Public health interventions and strategies to tackle the high prevalence of short sleep duration among children and adolescents are warranted.

Sedentary behavior patterns and adiposity in children: a study based on compositional data analysis

BACKGROUND

Between-person differences in sedentary patterns should be considered to understand the role of sedentary behavior (SB) in the development of childhood obesity. This study took a novel approach based on compositional data analysis to examine associations between SB patterns and adiposity and investigate differences in adiposity associated with time reallocation between time spent in sedentary bouts of different duration and physical activity.

METHODS

An analysis of cross-sectional data was performed in 425 children aged 7-12 years (58% girls). Waking behaviors were assessed using ActiGraph GT3X accelerometer for seven consecutive days. Multi-frequency bioimpedance measurement was used to determine adiposity. Compositional regression models with robust estimators were used to analyze associations between sedentary patterns and adiposity markers. To examine differences in adiposity associated with time reallocation, we used the compositional isotemporal substitution model.

RESULTS

Significantly higher fat mass percentage (FM%; β_ilr1 = 0.18; 95% CI: 0.01, 0.34; p = 0.040) and visceral adipose tissue (VAT; β_ilr1 = 0.37; 95% CI: 0.03, 0.71; p = 0.034) were associated with time spent in middle sedentary bouts in duration of 10-29 min (relative to remaining behaviors). No significant associations were found for short (< 10 min) and long sedentary bouts (≥30 min). Substituting the time spent in total SB with moderate-to-vigorous physical activity (MVPA) was associated with a decrease in VAT. Substituting 1 h/week of the time spent in middle sedentary bouts with MVPA was associated with 2.9% (95% CI: 1.2, 4.6), 3.4% (95% CI: 1.2, 5.5), and 6.1% (95% CI: 2.9, 9.2) lower FM%, fat mass index, and VAT, respectively. Moreover, substituting 2 h/week of time spent in middle sedentary bouts with short sedentary bouts was associated with 3.5% (95% CI: 0.02, 6.9) lower FM%.

CONCLUSIONS

Our findings suggest that adiposity status could be improved by increasing MVPA at the expense of time spent in middle sedentary bouts. Some benefits to adiposity may also be expected from replacing middle sedentary bouts with short sedentary bouts, that is, by taking standing or activity breaks more often. These findings may help design more effective interventions to prevent and control childhood obesity.

Outdoor physical activity, compliance with the physical activity, screen time, and sleep duration recommendations, and excess weight among adolescents

BACKGROUND

Spending time outdoor has been identified as an important way to achieve the physical activity required for maintaining and improving health and to lower sedentary time among young children. However, evidence of such relationships in adolescents is particularly limited. This study investigated the relationships between frequency of outdoor physical activity after school, compliance with the physical activity, screen time, and sleep duration recommendations, and overweight/obesity among adolescents.

METHODS

A total of 10 028 middle and high school students (mean age of 15.2 y) self-reported the number of weekdays they spent physically active outdoors after school. Physical activity, screen time, sleep duration, height, and weight were self-reported. Logistic regression models for the total sample and stratified by sex were adjusted for important covariates.

RESULTS

Overall, there was a positive gradient between the number of weekdays spent physically active outdoor after school and compliance with the physical activity (more than or equal to 60 min/day at moderate-to-vigorous intensity) and screen time (less than or equal to 2 h/day) recommendations while a negative gradient with overweight/obesity was observed. Significant sex differences were observed in the associations of outdoor physical activity after school with adherence to the sleep duration and physical activity recommendations. For example, outdoor physical activity after school on all 5 days was associated with greater odds of compliance with the sleep duration recommendation among males (OR = 1.53; 95% CI, 1.01-2.31), but not females (OR = 0.92; 95% CI, 0.65-1.30).

CONCLUSIONS

Results suggest that outdoor physical activity after school could be a behavioural target to increase compliance with the physical activity and screen time recommendations and to possibly tackle excess weight among adolescents.

Changes in weight status, quality of life and behaviours of South Australian primary school children: results from the Obesity Prevention and Lifestyle (OPAL) community intervention program

Background

Childhood obesity is a serious public health concern worldwide. Community-based obesity prevention interventions offer promise due to their focus on the broader social, cultural and environmental contexts rather than individual behaviour change and their potential for sustainability and scalability. This paper aims to determine the effectiveness of a South Australian community-based, multi-setting, multi-strategy intervention, OPAL (Obesity Prevention and Lifestyle), in increasing healthy weight prevalence in 9 to 11-year-olds.

Methods

A quasi-experimental repeated cross-sectional design was employed. This paper reports on the anthropometric, health-related quality of life (HRQoL) and behaviour outcomes of primary school children (9–11 years) after 2–3 years of intervention delivery. Consenting children from primary schools (20 intervention communities, INT; 20 matched comparison communities, COMP) completed self-report questionnaires on diet, activity and screen time behaviours. HRQoL was measured using the Child Health Utility 9D. Body Mass Index (BMI) z-score and weight status were determined from children’s measured height and weight. A multilevel mixed-effects model, accounting for clustering in schools, was implemented to determine intervention effect. Sequential Bonferroni adjustment was used to allow for multiple comparisons of the secondary outcomes.

Results

At baseline and final, respectively, 2611 and 1873 children completed questionnaires and 2353 and 1760 had anthropometric measures taken. The prevalence of children with healthy weight did not significantly change over time in INT (OR 1.11, 95%CI 0.92–1.35, p = 0.27) or COMP (OR 0.85, 95%CI 0.68–1.06, p = 0.14). Although changes in the likelihood of obesity, BMI z-score and HRQoL favoured the INT group, the differences were not significant after Bonferroni adjustment. There were also no significant differences between groups at final for behavioural outcomes.

Conclusions

OPAL did not have a significant impact on the proportion of 9 to 11-year-olds in the healthy weight range, nor children’s BMI z-score, HRQoL and behaviours. Long-term, flexible community-based program evaluation approaches are required .

Trial registration

ACTRN12616000477426 (12th April 2016, retrospectively registered).

Physical activity and sedentary activity: population epidemiology and concordance in Australian children aged 11-12 years and their parents

OBJECTIVES

To describe the epidemiology and parent-child concordance of objectively measured physical activity in a population-based sample of Australian parent-child dyads.

DESIGN

Cross-sectional study (Child Health CheckPoint) nested within the Longitudinal Study of Australian Children.

SETTING

Assessment centres in seven Australian cities and eight regional towns or home visits; February 2015-March 2016.

PARTICIPANTS

Of all CheckPoint families (n=1874), 1261 children (50% girls) and 1358 parent (88% mothers) provided objectively measured activity data, comprising 1077 parent-child dyads.

OUTCOME MEASURES

Activity behaviour was assessed by GENEActiv accelerometer. Duration of moderate-to-vigorous physical activity (MVPA) and vigorous physical activity and sedentary behaviour (SB) were derived using Cobra custom software, along with MVPA/SB fragmentation and mean daily activity. Pearson's correlation coefficients and linear regression estimated parent-child concordance. Survey weights and methods accounted for the complex sample design and clustering.

RESULTS

Although parents had average lower accelerometry counts than children (mean [SD] 209 [46] vs 284 [71] g.min), 93% of parents met MVPA daily duration guidelines on published cutpoints (mean [SD] 125 [63] min/day MVPA), compared with only 15% of children (mean 32 [27] min). Parents showed less daily SB duration (parents: 540 [101], children: 681 [69] minutes) and less fragmented accumulation of MVPA (parents: α=1.85, children: α=2.00). Parent-child correlation coefficients were 0.16 (95% CI 0.11 to 0.22) for MVPA duration, 0.10 (95% CI 0.04 to 0.16) for MVPA fragmentation, 0.16 (95% CI 0.11 to 0.22) for SB duration and 0.18 (95% CI 0.12 to 0.23) for SB fragmentation.

CONCLUSIONS

Standardised cutpoints are needed for objective activity measures to inform activity guidelines across the lifecourse. This may reflect large amounts of time in non-shared environments (school and work).

Compensatory changes in physical activity and sedentary time in children and adolescents with cystic fibrosis

Physical activity (PA) is a key element in Cystic Fibrosis (CF) treatment strategies, yet little is known as to whether activity compensation occurs. This study examined whether PA and/or sedentary time on one day were temporally associated with time spent in these intensities the following day in youth with CF. Time spent sedentary and in different PA intensities were objectively-measured for seven consecutive days in 50 youth (22 boys; 12.0 ± 2.7 years); 25 with mild-to-moderate CF and 25 age- and sex-matched controls. Multilevel analyses (day and child) were conducted using generalised linear latent and mixed models. On any given day, every additional 10 minutes spent in sedentary time or moderate-to-vigorous physical activity (MVPA) were associated with 1.9 (95%CI: -3.6 to -1.2) and 12.4 (95%CI: -22.1 to -2.9) minutes less sedentary time the following day, respectively. These temporal associations were also observed when split by group (3.1 vs. 1.9 minutes for healthy and CF, respectively). These findings indicate that youth do not compensate their PA, irrespective of disease status, between days, but may compensate their sedentary time between days. Experimental studies are warranted to fully elucidate whether compensatory responses to PA and sedentary time occur, which is fundamental for informing PA promotion strategies.

Environmental correlates of total and domain-specific sedentary behaviour in young people. The UP&DOWN study

This study investigated the associations between the characteristics of the nearby physical environment with the total and domain-specific leisure-time sedentary behaviour (SB) in young people. The study included 1578 youth (9-18 years) from the UP&DOWN study. Total leisure-time SB was objectively-assessed by accelerometers. Participants self-reported the time spent during leisure-time in different domains of SB (i.e. screen-based, educational-based, social-based, and other-based SB). Information regarding the basic characteristics of the house, the perceived neighbourhood environment, the amount of physical activity facilities, equipment and materials attainable at home, and the media equipment available at home and in the own bedroom was collected. Linear mixed models were performed, including school and city as random effects. The availability of yard was related to lower total SB and time spent surfing the Internet in boys, but not in girls. More favourable perceived neighbourhood environment was associated with lower total SB and time spent playing video games in girls, but not in boys. The amount of physical activity materials at home was negatively associated with screen-based SB, while the availability of a computer in the own bedroom was positively related to the time spent surfing the Internet in boys and girls. The number of televisions at home and having a computer in the own bedroom was associated with lower time in educational-based SB in boys and girls, respectively. Increasing the number of PA materials at home and decreasing the number of TVs at home and the availability of a computer in the bedroom could improve SB profiles of youth.

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.

Association between Clustering of Lifestyle Behaviors and Health-Related Physical Fitness in Youth: The UP&DOWN Study

OBJECTIVES

To examine clustering of lifestyle behaviors in Spanish children and adolescents based on screen time, nonscreen sedentary time, moderate-to-vigorous physical activity, Mediterranean diet quality, and sleep time, and to analyze its association with health-related physical fitness.

STUDY DESIGN

The sample consisted of 1197 children and adolescents (597 boys), aged 8-18 years, included in the baseline cohort of the UP&DOWN study. Moderate-to-vigorous physical activity was assessed by accelerometry. Screen time, nonscreen sedentary time, Mediterranean diet quality, and sleep time were self-reported by participants. Health-related physical fitness was measured following the Assessing Levels of Physical Activity battery for youth. A 2-stage cluster analysis was performed based on the 5 lifestyle behaviors. Associations of clusters with fatness and physical fitness were analyzed by 1-way ANCOVA.

RESULTS

Five lifestyle clusters were identified: (1) active (n = 171), (2) sedentary nonscreen sedentary time-high diet quality (n = 250), (3) inactive-high sleep time (n = 249 [20.8%]), (4) sedentary nonscreen sedentary time-low diet quality (n = 273), and (5) sedentary screen time-low sleep time (n = 254). Cluster 1 was the healthiest profile in relation to health-related physical fitness in both boys and girls. In boys, cluster 3 had the worst fatness and fitness levels, whereas in girls the worst scores were found in clusters 4 and 5.

CONCLUSIONS

Clustering of different lifestyle behaviors was identified and differences in health-related physical fitness were found among clusters, which suggests that special attention should be given to sedentary behaviors in girls and physical activity in boys when developing childhood health prevention strategies focusing on lifestyles patterns.

Systematic Review of Childhood Sedentary Behavior Questionnaires: What do We Know and What is Next?

BACKGROUND

Accurate measurement of child sedentary behavior is necessary for monitoring trends, examining health effects, and evaluating the effectiveness of interventions.

OBJECTIVES

We therefore aimed to summarize studies examining the measurement properties of self-report or proxy-report sedentary behavior questionnaires for children and adolescents under the age of 18 years. Additionally, we provided an overview of the characteristics of the evaluated questionnaires.

METHODS

We performed systematic literature searches in the EMBASE, PubMed, and SPORTDiscus electronic databases. Studies had to report on at least one measurement property of a questionnaire assessing sedentary behavior. Questionnaire data were extracted using a standardized checklist, i.e. the Quality Assessment of Physical Activity Questionnaire (QAPAQ) checklist, and the methodological quality of the included studies was rated using a standardized tool, i.e. the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist.

RESULTS

Forty-six studies on 46 questionnaires met our inclusion criteria, of which 33 examined test-retest reliability, nine examined measurement error, two examined internal consistency, 22 examined construct validity, eight examined content validity, and two examined structural validity. The majority of the included studies were of fair or poor methodological quality. Of the studies with at least a fair methodological quality, six scored positive on test-retest reliability, and two scored positive on construct validity.

CONCLUSION

None of the questionnaires included in this review were considered as both valid and reliable. High-quality studies on the most promising questionnaires are required, with more attention to the content validity of the questionnaires. PROSPERO registration number: CRD42016035963.

Revisiting Factors Associated With Screen Time Media Use: A Structural Study Among School-Aged Adolescents

BACKGROUND

Screen-based media overuse has been related to harmful consequences especially among children and adolescents. Given their complex interrelationships, predictors of screen time (ST) should be analyzed simultaneously rather than individually to avoid incomplete conclusions.

METHODS

Structural equation models were conducted to examine associations between media ST (television, video games, and computers) along with harmful consequences in adolescents' well-being, such as underweight and overweight, depression, and school failure. Predictors included individual (gender, age, and physical activity), family (structure and socioeconomic background), and substance use variables. We used the Health Behaviour in School-aged Children survey organized in 2014, including eighth- and ninth-grade students living in France (N = 3720).

RESULTS

Students reported spending 3 hours per day in front of each media. Spending more than 2 hours behind each of those 3 media was associated with lower life satisfaction, less physical activity, active school bullying, and grade repetition. Socioeconomic status was the most important predictor of ST, whereas regular substance uses showed modest associations.

CONCLUSION

The main implication of our findings is to sensitize parents and stakeholders about the limitation of ST, including their own use that adolescents are likely to mimic. Alternative measures such as off-line time should be encouraged.

A latent growth curve model to estimate electronic screen use patterns amongst adolescents aged 10 to 17 years

Background

High quality, longitudinal data describing young people’s screen use across a number of distinct forms of screen activity is missing from the literature. This study tracked multiple screen use activities (passive screen use, gaming, social networking, web searching) amongst 10- to 17-year-old adolescents across 24 months.

Methods

This study tracked the screen use of 1948 Australian students in Grade 5 (n = 636), Grade 7 (n = 672), and Grade 9 (n = 640) for 24 months. At approximately six-month intervals, students reported their total screen time as well as time spent on social networking, passive screen use, gaming, and web use. Patterns of screen use were determined using latent growth curve modelling.

Results

In the Grades 7 and 9 cohorts, girls generally reported more screen use than boys (by approximately one hour a day), though all cohorts of boys reported more gaming. The different forms of screen use were remarkably stable, though specific cohorts showed change for certain forms of screen activity.

Conclusion

These results highlight the diverse nature of adolescent screen use and emphasise the need to consider both grade and sex in future research and policy.

Sedentary behavior and physical activity of young adult university students

Movement and non-movement behaviors include sleep, sedentary behavior (SB) and physical activity (PA). While young adults are generally perceived as healthy, the level and relationship of SB and PA in college-age students has not been greatly explored. The purpose of this study was to objectively measure the levels of SB and PA in 18-20 year-old university students, record their self-reported extracurricular activities, and explore the relationship of all these with body mass index (BMI) and waist circumference (WC). Male (n = 48) and female (n = 46) students participated in this cross-sectional study. Hierarchical multiple regression analyses were used to examine time spent in SB, moderate to vigorous physical activity (MVPA), number of self-reported sedentary extracurricular activities, and their relation to the dependent variables of BMI and WC. In correlation analyses, SB (p < .001) and MVPA (p = .017) both were negatively associated with BMI, and "other" race or ethnicity (African American, Hispanic, mixed; p = .013) and number of self-reported sedentary extracurricular activities (p = .006) were positively associated with BMI. In the WC regression model, SB (p = .018) was negatively associated and number of self-reported sedentary extracurricular activities (p = .006) was positively associated with WC. University students may be both highly active and highly sedentary. Future researchers should consider targeting interventions to reduce SB in addition to improving PA.

Socioeconomic inequality in screen time frequency in children and adolescents: the weight disorders survey of the CASPIAN IV study

BACKGROUND

This study aimed to assess the socioeconomic inequality and determinants of screen time (ST) frequency in Iranian children and adolescents.

METHODS

This nationwide study was conducted as part of a national school-based surveillance program among 36,486 students consisting of 50.79% boys and 74.23% urban inhabitants, aged 6-18 years, living in urban and rural areas of 30 provinces of Iran. Socioeconomic inequality in ST, including the time spent for ST, watching TV and leisure-time working with computer, was assessed across quintiles of SES using concentration index (C) and slope index of inequality (SII).

RESULTS

Overall, 36,486 students completed the study (response rate 91.25%). Their mean (SD) age was 12.14 (3.36) years. The national estimation of frequency of ST was 31.66% (95% CI 31.16-32.17) with ascending change from 20.80% (95% CI 19.81-21.82) to 36.66% (95% CI 35.47-37.87) from the first to the last quintal of SES. Estimated C value at national level was positive (0.08), which indicate inequality was in favor of low SES groups. Considering the SII values, at national level [- 0.16 (- 0.39, 0.06)], the absolute difference in ST frequency between the bottom and top of the socioeconomic groups had descending trends. In multivariate logistic regression model, family history of obesity, generalized obesity and age were the main significant determinants of prolonged ST, watching TV, and computer working (P < 0.001).

CONCLUSIONS

Socioeconomic inequality in ST frequency was in favor of low SES groups. These findings are useful for health policies, better programming and future complementary analyses.

Cross-sectional associations between maternal parenting styles, physical activity and screen sedentary time in children

Background

Children’s activity level, including physical activity (PA) and screen sedentary time (SST), is influenced by environmental factors in which parents play a critical role. Different types of parenting styles may influence children’s activity level. Inconsistent results were found on the association between parenting styles and PA, and few studies tested the association between parenting styles and SST. This study examined the association between parenting styles, PA and SST and the modifying effect of children’s gender and maternal educational level on these associations.

Methods

Cross-sectional data were collected from parents of children aged 8–11 years old who completed a web-based non-standardized questionnaire (N = 4047). Since 85% of the questionnaires were filled in by mothers, parenting styles are mainly reported by mothers. Multiple linear regression techniques were used to assess the associations between parenting styles (authoritative, permissive, authoritarian and neglectful), and PA and SST (mean min/day). The modifying effect of children’s gender and maternal educational level on these associations was explored. P values ≤.0125 were considered as statistically significant based on the Bonferroni correction for four primary analyses.

Results

The neglectful parenting style was most widely used (35.3%), while the authoritarian style was least common (14.8%). No significant association was found between parenting styles and PA level. As regards SST, an authoritative parenting style was significantly associated with lower SST in boys while a neglectful parenting style was significantly associated with higher SST in both boys and girls. When the mother had a medium educational level, an authoritative parenting style was significantly associated with lower SST while neglectful parenting was significantly associated with higher SST.

Conclusions

No association was found between parenting styles and PA. However, an authoritative parenting style was associated with a reduction in SST and a neglectful parenting style with an increase in SST, especially in boys and in children whose mother had a medium education level. Future studies of parenting practices are needed to gain more insight into the role of parents in children’s PA and SST levels, as a basis for the development of interventions tailored to support parents in stimulating PA and reducing SST in children.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Correlates of sedentary behaviour in 8- to 10-year-old children at elevated risk for obesity

The purpose of this study was to describe correlates of sedentary behaviour (SED) in children at elevated risk of obesity because of parental obesity. Participants were 534 children aged 8-10 years with ≥ 1 obese parent. SED and physical activity (PA) were measured by accelerometer, screen time by self-report, and height, weight, waist circumference, and cardiovascular fitness objectively measured. Data describing the child, parents, friends, and home and neighbourhood environments were from child self-report. Higher total SED time was significantly positively associated with child's age, mother's age, Tanner stage, weight status or waist circumference, less self-reported PA, choosing screen time over PA/sport, mother saying PA/sport good for them, and fewer weekly physical education (PE) classes. Exceeding 2 h/day screen time was significantly associated with child's age, male sex, weight status or waist circumference, choosing screen time over PA/sport, and dinnertime TV viewing. Children regularly watching TV with dinner had 2.3 times greater odds (95% confidence interval (CI) 1.52, 3.58) of exceeding screen time guidelines compared with children rarely watching TV with dinner; children reporting ≤ 2 PE classes/week had 2.4 times greater odds (95% CI 1.41, 4.10) of being in the highest SED tertile compared with children reporting >2 PE classes/week. Hence, the most sedentary children are older, more biologically mature, less active, more overweight/obese, have fewer PE classes, and are more likely to choose screen time over PA and watch TV with dinner compared with less sedentary children. PE opportunities and mealtime TV viewing are potentially modifiable targets for reducing total SED and screen time in children.

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.

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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.

Systematic review of sedentary behaviour and health indicators in school-aged children and youth: an update

This systematic review is an update examining the relationships between objectively and subjectively measured sedentary behaviour and health indicators in children and youth aged 5–17 years. EMBASE, PsycINFO, and Medline were searched in December 2014, and date limits were imposed (≥February 2010). Included studies were peer-reviewed and met the a priori-determined population (apparently healthy children and youth, mean age: 5–17 years), intervention (durations, patterns, and types of sedentary behaviours), comparator (various durations, patterns, and types of sedentary behaviours), and outcome (critical: body composition, metabolic syndrome/cardiovascular disease risk factors, behavioural conduct/pro-social behaviour, academic achievement; important: fitness, self-esteem) study criteria. Quality of evidence by outcome was assessed using the Grading of Recommendations Assessment, Development, and Evaluation framework. Due to heterogeneity, a narrative analysis was conducted. A total of 235 studies (194 unique samples) were included representing 1 657 064 unique participants from 71 different countries. Higher durations/frequencies of screen time and television (TV) viewing were associated with unfavourable body composition. Higher duration/frequency of TV viewing was also associated with higher clustered cardiometabolic risk scores. Higher durations of TV viewing and video game use were associated with unfavourable behavioural conduct/pro-social behaviour. Higher durations of reading and doing homework were associated with higher academic achievement. Higher duration of screen time was associated with lower fitness. Higher durations of screen time and computer use were associated with lower self-esteem. Evidence ranged from “very low” to “moderate” quality. Higher quality studies using reliable and valid sedentary behaviour measures should confirm this largely observational evidence.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Waist Circumference and Objectively Measured Sedentary Behavior in Rural School Adolescents

BACKGROUND

Research on relationships between lifestyle behaviors and adiposity in school youth is potentially important for identifying subgroups at risk. This study evaluates the associations between waist circumference (WC) and objective measures of sedentary behavior (SB) in a sample of rural school adolescents.

METHODS

The sample included 254 students (114 boys, 140 girls), 13-16 years of age, from rural regions of the Portuguese midlands. Height, weight, and WC were measured. Cardiorespiratory fitness (CRF) was assessed with the 20-m shuttle-run test. An uniaxial GT1M accelerometer was used to obtain 5 consecutive days of physically activity (PA) and SB. Multiple linear regression was used to test associations between WC and SB, adjusted for several potential confounders (age, sex, PA, CRF, parental education).

RESULTS

SB was not significantly associated with the WC, neither in the unadjusted model nor after adjustment for all potential confounders. In the final model, the unique significant predictor of the WC was cardiorespiratory fitness (β = -0.82; 95% confidence interval [CI], -1.02 to -0.62).

CONCLUSION

WC was not independently associated with SB time in rural school adolescents. Future research is claimed among rural adolescents in different geographic contexts to try to clarify recent findings of less studied communities.

Parental influences on adolescent video game play: a study of accessibility, rules, limit setting, monitoring, and cybersafety

Adolescents' video gaming is increasing at a rapid rate. Yet, little is known about what factors contribute toward more hours of gaming per week, as well as what factors may limit or protect adolescents from excessive gaming. The aim of the present study was to examine associations between adolescents' accessibility to video gaming devices, the locations played (i.e., bedroom, shared rooms), parental regulation of technology use, and the amount of hours spent video gaming during the week (weekdays vs. weekends). Adolescents (N=422; age 16.3±2.0 years, 41% male) completed an online questionnaire battery, including demographics, video gaming behaviors (e.g., hours played weekdays/weekends, time of day played, devices owned, locations played, etc.), and a questionnaire measuring aspects of parents' regulation of game playing (e.g., rules, limit setting, co-gaming). Accessibility to the adolescents' own devices, but not shared devices or device portability, was predictive of hours gaming on weekdays and weekends. Location (i.e., bedroom) was associated with increased gaming across the week. Parents discussing cybersafety was predictive of lower hours of gaming (weekdays and weekends). However, limit setting, monitoring, and co-gaming showed no significant effects. Adolescents' access to their own gaming equipped devices, as well as gaming in their bedrooms, were linked to increased hours of gaming. The findings suggest that in order to curb the increase in hours gaming, parents are advised to delay the ownership of adolescents' devices, encourage use in shared rooms, and discuss aspects of cybersafety with their teenage children.

[Prevalence of excessive screen time and associated factors in adolescents]

OBJECTIVE

To determine the prevalence of excessive screen time and to analyze associated factors among adolescents.

METHODS

This was a cross-sectional school-based epidemiological study with 2,874 high school adolescents with age 14-19 years (57.8% female) from public and private schools in the city of João Pessoa, PB, Northeast Brazil. Excessive screen time was defined as watching television and playing video games or using the computer for more than two hours per day. The associated factors analyzed were: sociodemographic (gender, age, economic class, and skin color), physical activity and nutritional status of adolescents.

RESULTS

The prevalence of excessive screen time was 79.5% (95%CI: 78.1-81.1) and it was higher in males (84.3%) compared to females (76.1%; p<0,001). In multivariate analysis, adolescent males, aged 14-15 years old, of higher economic classes had higher chances of exposure to excessive screen time. The level of physical activity and nutritional status of adolescents were not associated with excessive screen time.

CONCLUSIONS

The prevalence of excessive screen time was high and varied according to sociodemographic characteristics of adolescents. It is necessary to develop interventions to reduce the excessive screen time among adolescents, particularly in subgroups with higher exposure.

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

PURPOSE

To examine tracking of weekday and weekend screen time (ST; i.e., television [TV] and computer [PC] time) from early adolescence to early adulthood and to identify social ecological predictors of weekday and weekend ST among boys and girls separately.

METHODS

Data were retrieved from elementary schools (n = 59) in Flanders (Belgium). At baseline, 1,957 children (age, 9.9 ± .43 years) and one of the parents filled out a questionnaire on sedentary behavior and individual, social, and environmental variables. After a 10-year follow-up period, six hundred fifty-five 20-year-olds (age, 19.9 ± .43 years) filled out an adapted questionnaire on sedentary behavior, of which 593 contained full data at baseline and follow-up. Multiple regressions were performed to examine predictors (baseline) of ST (follow-up), and logistic regressions were used to analyze tracking of ST.

RESULTS

For boys, a consistent positive predictor of weekday and weekend TV and PC time at follow-up was ST at baseline (p < .01). For girls, drinking more soda at baseline predicted more weekday and weekend TV and PC time at follow-up (p ≤ .02). Some other individual variables also predicted ST in both boys and girls. Tracking was only found among boys; those exceeding the ST guideline at baseline were three to five times more likely to exceed this guideline at follow-up (p ≤ .001). Tracking was not present among girls.

CONCLUSIONS

To minimize TV and PC time during early adulthood, interventions for adolescent boys should focus on minimizing ST. For girls, focus should be on healthy eating. However, more research is warranted to confirm these conclusions.

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.

Mothers' perceived proximity to green space is associated with TV viewing time in children: the Growing Up in Scotland study

OBJECTIVE

The aim of this study is to investigate whether mothers' perception of distance from home to green/open spaces is associated with their child's screen time.

METHOD

We used mother-reported data from sweep six (2010-2011) of the Growing Up in Scotland study (n=3586 children aged 5.9yrs) to examine associations between walking distance from home to green/open space and screen time (TV viewing time/computer use). Analyses were adjusted for age, sex and other pre-specified covariates, including sport/exercise participation, mental and general health, birth weight, parental socio-economic group (SEG) and smoking status.

RESULTS

Children living the furthest distance from green/open spaces (>20minutes' walking distance) displayed over 2h (95% CI, 0.65 to 3.51) more weekly TV time than the reference category (<5minutes' walking distance). Compared to children in the reference category, those in the >20minute category had worse mental health (mean SDQ [Strengths and Difficulties Questionnaire] score±SD, 7.0±4.6 vs. 8.7±6.2) and general health (% fair-poor, 4.6 vs. 8.6), and were more likely to come from lower SEG households.

CONCLUSION

Mothers' perceived distance from home to green/open spaces was associated with child's TV time at age 5.9years.