Understanding children's sedentary behaviour : a qualitative study of the family home environment

Electronic media (EM) (television, electronic games and computer) use has been associated with overweight and obesity among children. Little is known about the time spent in sedentary behaviour (SB) among children within the family context. The aim of this study was to explore how the family home environment may influence children's electronic-based SB. Focus groups and family interviews were conducted with 11- to 12-year old children (n = 54) and their parents (n = 38) using a semi-structured discussion guide. Transcripts were analysed using a thematic content approach. A brief self-completed questionnaire was also used to measure leisure behaviour and electronic devices at home. Children incorporated both sedentary and physical activities into their weekly routine. Factors influencing children's EM use included parent and sibling modelling and reinforcement, personal cognitions, the physical home environment and household EM use rules and restrictions. Participants were not concerned about the excessive time children spent with EM. This under-recognition emerged as a personal influencing factor and was viewed as a major barrier to modifying children's electronic-based SB. Efforts to reduce SB in children should focus on the influencing factors that reciprocally interact within the family home. An emphasis on increasing awareness about the risks associated with spending excessive time in screen-based activities should be a priority when developing intervention strategies aimed at modifying the time children spend in SB.

A systematic review of the validity and reliability of sedentary behaviour measures used with children and adolescents

The aim of this review was to evaluate the reliability and validity of methods used to assess the multiple components of sedentary behaviour (i.e. screen time, sitting, not moving and existing at low energy expenditure) in children and adolescents. Twenty-six studies met our inclusion criteria and were reviewed. Thirteen studies reported the reliability of self- and proxy-report measures of sedentary behaviour and seven of these were found to have acceptable test–retest reliability. Evidence for the criterion validity of self- and proxy-report measures was examined in three studies with mixed results. Seven studies examined the reliability and/or validity of direct observation and the findings were generally positive. Five studies demonstrated the utility of accelerometers to accurately classify sedentary behaviour. Self-report measures provide reliable estimates of screen time, yet their validity remains largely untested. While accelerometers can accurately classify participants’ behaviour as sedentary, they do not provide information about type of sedentary behaviour or context. Studies utilizing measures of sedentary behaviour need to more adequately report on the validity and reliability of the measures used.We recommend the use of objective measures of sedentary behaviour such as accelerometers, in conjunction with subjective measures (e.g. self-report), to assess type and context of behaviour.

Physical activity, sedentary behaviour and depression among socio-economically disadvantaged women

Promoting physical activity, particularly for leisure and transport, could be an important aspect in preventing depression amongst women living in disadvantaged neighbourhoods. Furthermore, including some aspect of social physical activity and reducing time spent in sedentary behaviours may further reduce risk of depression.

Lack of relationship between sedentary behaviour and vascular function in children

Some evidence suggests that sedentary behaviour is independently associated with cardiovascular (CV) risk. Endothelial dysfunction is the earliest detectable manifestation of CVD and a strong independent predictor of CV events. No previous study has examined the relationship between sedentary behaviour and endothelial function. We assessed the basal association between conduit artery endothelial function and sedentary behaviour in children, along with the correlation between changes in sedentary behaviour and endothelial function. We studied 116 children (70$: 10.7 ± 0.3; 46#: 10.7 ± 0.3 years) on two occasions; in the summer (June) and late autumn (November). We assessed endothelial function via flowmediated dilation (FMD) using high-resolution Doppler ultrasound. Sedentary behaviour (SB) was assessed using objective uni-axial accelerometry. At baseline, there were no significant differences between girls and boys for any measured variables with the exception of total physical activity time. FMD was not associated with sedentary behaviour in either group or in the cohort as a whole. Although FMD decreased (10.0 ± 4.3–7.9 ± 3.9%, P\0.001) and SB increased (499.1 ± 103.5–559 ± 81.6 min/day, P\0.001) between the seasons, no relationship existed between changes in these variables. Our data suggest that sedentary behaviour and changes in sedentary behaviour are not associated with endothelial function in children.

Is the neighbourhood environment associated with sedentary behaviour outside of school hours among children?

Background Little is known about neighbourhood environments and children’s sedentary behaviour outside school hours.
Purpose This study aims to examine the associations between public open spaces (POS), parent perceptions of the neighbourhood and children’s sedentary behaviours.
Methods Parents reported their child’s television viewing and computer/electronic game time and their perceptions of the physical and social neighbourhood. Children’s sedentary
time was objectively assessed. The closest POS was audited.
Results Cross-sectionally, living near a POS with a water feature and greater parental satisfactionwith POS quality were negatively associated with computer/e-games; greater POS area was negatively associated with TV viewing. Longitudinally, living in a cul-de-sac and greater satisfaction with POS quality were negatively associated with computer/e-games and TV viewing, respectively. Awalking path in the POS was positively associated with computer/e-games.
Conclusion Neighbourhood features appear to positively and negatively influence children’s sedentary behaviours, highlighting the complexity of urban planning on behaviour. Further age- and context-specific studies are required.

Patterns of physical activity and sedentary behaviour in preschool children

Background
Little is known about patterns of sedentary behavior (SB) and physical activity among preschoolers. Therefore, in this observational study patterns of SB and moderate-to-vigorous physical activity (MVPA) were examined in detail throughout the week in preschool-aged boys and girls.

Methods
A sample of 703 Melbourne preschool children (387 boys; 4.6 ± 0.7 y) were included in data analysis. SB and MVPA data were collected using accelerometry over an eight-day period. Percentage of time per hour in SB and in MVPA between 08:00 h and 20:00 h was calculated. Multi-level logistic regression models were created to examine the hour-by-hour variability in SB and MVPA for boys and girls across weekdays and weekend days. Odds ratios (OR) were calculated to interpret differences in hour-by-hour SB and MVPA levels between boys and girls, and between weekdays and weekend days.

Results
The highest SB levels co-occurred with the lowest MVPA levels from the morning till the early afternoon on weekdays, and during the morning and around midday on weekends. Besides, participation in SB was the lowest and participation in MVPA was the highest from the mid afternoon till the evening on weekdays and weekend days. The variability across the hours in SB and, especially, in MVPA was rather small throughout weekdays and weekends. These patterns were found in both boys and girls. During some hours, girls were found to be more likely than boys to demonstrate higher SB levels (OR from 1.08 to 1.16; all p < 0.05) and lower MVPA levels (OR from 0.75 to 0.88; all p < 0.05), but differences were small. During weekends, hour-by-hour SB levels were more likely to be lower (OR from 0.74 to 0.98; all p < 0.05) and hour-by-hour MVPA levels were more likely to be higher (OR from 1.15 to 1.50; all p < 0.05), than during weekdays, in boys and girls.

Conclusion
Entire weekdays, especially from the morning till the early afternoon, and entire weekend days are opportunities to reduce SB and to promote MVPA in preschool-aged boys and girls. Particularly weekdays hold the greatest promise for improving SB and MVPA. No particular time of the week was found where one sex should be targeted.

Associations between usual school lunch attendance and eating habits and sedentary behaviour in French children and adolescents

Background/Objective: Our objective was to investigate whether school lunch attendance was associated with overall eating habits and sedentary behaviour in a French sample of children and adolescents.

Subjects/Methods: Data for the study were taken from the second French cross-sectional dietary survey (INCA2-2006-07). In total, 1413 school children aged 3–17 years old were classified according to their school type and their usual school lunch attendance. Eating habits included meal regularity, dietary diversity, purchase in vending machine, snacking habits and frequency of eating in fast-foods. Two composite indices of eating habits were derived from multiple correspondence analyses. Sedentary behaviour was assessed by the average daily screen times for TV and computer. The association between school lunch attendance and each variable was tested. Multivariate association between school lunch attendance and the composite indices of eating habits and sedentary behaviours was studied.

Results: In all, 69.0% (CI95%: 64.2–73.9) of secondary school children and 63.0% (CI95%: 58.5–67.5) of pre- and elementary school children usually attended school lunch at least once a week. Pre- and elementary school children attending school lunches showed a higher dietary diversity score (P=0.02) and ate morning snacks more frequently (P=0.02). In secondary school children, attending school canteen was related to a lower rate of skipping breakfast (P=0.04) and main meals (P=0.01). In all school children, school lunch attendance was simultaneously associated with healthier overall eating habits and less sedentary behaviour.

Conclusion: In France, children attending school canteens seem to have healthier eating habits and display less sedentary behaviour, independently of their socio-economic and demographic background.