Associations of friendship and children's physical activity during and outside of school: A social network study.

Friendships play a significant role in child development and may influence children's physical activity (PA). Using a whole-network approach, this study examined whether school-based friends are more similar in their pedometer-measured PA compared to children who are not friends, and whether these patterns vary by gender, strength of friendship (best vs. close friends), and during vs. outside of school. The analytical sample included 706 grade 5 students (10- to 11-years-old) in 27 schools who were participating in the APPLE Schools project (Alberta Project Promoting healthy Living for Everyone in schools) in Edmonton and Fort McMurray, Alberta, Canada in the spring of 2013. Data collected included student and parent survey responses, time-stamped pedometer data for nine consecutive days, and close and best within-school and within-grade friendship nominations. We used Multiple Regression - Quadratic Assignment Procedure (MR-QAP) to examine the effect of friendship ties on PA similarity overall, and for during and outside of school periods, controlling for covariates and clustering within schools. When all friendships (i.e., close and best) were considered, female friends exhibited more similar levels of overall PA than non-friends, and these findings held for school days, the during-school period, and non-school days. When close and best friends were examined separately in the same model (non-friends as the referent), both close and best friends were more similar than non-friends. The close friendship findings held for non-school days, and the best friendship findings held for school days, including the during-school and before- and after-school periods. For males, only reciprocated best friends had more similar levels of overall PA compared to unreiprocated friendships and non-friends. Programs and policies that focus on increasing PA in children may benefit from incorporating friendship-based strategies and programming, especially for females.

Long-term effects of comprehensive school health on health-related knowledge, attitudes, self-efficacy, health behaviours and weight status of adolescents.

BACKGROUND: APPLE Schools is a Comprehensive School Health (CSH) project, started in schools in socioeconomically disadvantaged areas where dietary habits are poor, physical activity (PA) levels are low, and obesity rates are high. Earlier research showed program effects whereby energy intake, PA and weight status of students in APPLE Schools had reached similar levels as that of students in other schools. However, it is unknown whether the effects of CSH are sustained when children grow into adolescents. Effects of APPLE Schools on health-related knowledge, attitudes, self-efficacy, diet, PA, and weight status, seven years after the start of the project, when students were in junior high and high school were assessed. We hypothesised that APPLE School graduates and comparison school graduates will remain at similar levels for these indicators. METHODS: In the 2015/16 school year, junior high and high school graduates (grades 7-12) in Northern Alberta, Canada participated in a Youth Health Survey. Participants included graduates from APPLE elementary schools (n = 202) and comparison elementary schools (n = 338). Health-related knowledge, attitudes, self-efficacy, diet (24-h dietary recall), PA (pedometer step count) and weight status were assessed. Mixed effects regression was employed to assess differences in these outcomes between APPLE School graduates and comparison school graduates. Comparisons between elementary school (2008/09) and junior high/high school (2015/16) of self-efficacy, PA and weight status were also conducted. RESULTS: APPLE School graduates did not significantly differ from comparison school graduates on any outcomes (i.e. knowledge, attitudes, self-efficacy, diet, PA, and weight status). Additionally, no significant differences existed in the comparisons between 2008/09 and 2015/16. CONCLUSION: Our findings of no difference between the APPLE School graduates and comparison school graduates suggest that the effects of APPLE Schools may continue into adolescence or the new school environment may have an equalizing effect on the students. Since lifestyle practices are adopted throughout childhood and adolescence, and the school environment has an important influence on development, an extension of CSH initiatives into junior high/high schools should be considered. This will help to consolidate and support the continuance of healthy lifestyle messages and practices throughout childhood and adolescence.

Influence of physical activity, sedentary behavior, and diet quality in childhood on the incidence of internalizing and externalizing disorders during adolescence: a population-based cohort study.

PURPOSE: Studies among youth suggest that physical inactivity, sedentary behaviors, and poor diet quality are associated with poor mental health. Few population-based studies have investigated these relationships longitudinally. We examined the association between physical activity, sedentary behaviors, and diet quality in childhood and the incidence of internalizing and externalizing disorders throughout adolescence. METHODS: We linked health behavior survey data from 2003 among 10- to 11-year-old children across Nova Scotia, Canada, with administrative health care data from 2003 to 2011. Students' diet quality was assessed using the Harvard Food Frequency Questionnaire. Physical activity and sedentary behaviors were self-reported, and internalizing and externalizing disorders were diagnosed by a physician. We applied Cox regression to examine the associations of the health behaviors with the incidence of internalizing and externalizing disorders between 2003 and 2011. RESULTS: Of the 4861 participating students, 23.7% and 9.4% had a diagnosis of internalizing and externalizing disorders, respectively. The incidences of internalizing and externalizing disorders were higher among students who were less physically active and spent more time using computers and video games. CONCLUSIONS: These findings suggest that promoting an active lifestyle in childhood may contribute to the prevention of both internalizing and externalizing disorders during adolescence.

Does School-Based Health Promotion Affect Physical Activity on Weekends? And, Does It Reach Those Students Most in Need of Health Promotion?

OBJECTIVE: To determine whether a school-based health promotion program affects children's weekend physical activity and whether this effect varies according to socioeconomic-status. METHODS: This was a quasi-experimental trial of school-based programs on physical activity levels implemented in disadvantaged neighborhoods in Alberta, Canada. In 2009 and 2011, 7 full days of pedometer data were collected from cross-sectional samples of grade 5 students (age 10-11 years) from 10 intervention schools in low-socioeconomic neighbourhoods and 20 comparison schools in middle-socioeconomic neighbourhoods. Multilevel models assessed differences in step-counts between intervention and comparison groups over-time by weight (objectively measured) and socioeconomic status subgroups. RESULTS: In 2009, children from intervention schools were less active on weekends relative to comparison schools (9212 vs. 11186 steps/day p<0.01). Two years later, daily step-counts on weekend days among children in low socioeconomic intervention schools increased such that they approximated those of children from middle socioeconomic comparison schools (12148 vs. 12121 steps/day p = 0.96). The relative difference in steps between intervention and comparison schools on weekends reduced from -21.4% to 0.2% following the intervention. The normalization of weekend step counts was similar for normal weight (-21.4% to +2.0%) and overweight (-19.1 to +3.9%) children, and was balanced across socioeconomic subgroups. CONCLUSIONS: These data suggest that school-based health promotion is effective for reducing inequities in physical activity levels outside school hours. Investments in school-based health promotion lead to behavior modification beyond the school environment. TRIAL REGISTRATION: ClinicalTrials.gov NCT01914185.