Applied Physiology, Nutrition, and Metabolism

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1 Is adherence to the Canadian 24-hour movement behaviour guidelines for school-aged children and youth associated with improved indicators of physical, mental, and social health? Journal: Applied Physiology, Nutrition, and Metabolism Manuscript ID apnm r2 Manuscript Type: Article Date Submitted by the Author: 02-Feb-2017 Complete List of Authors: Janssen, Ian; Queens University, Roberts, Karen; Public Health Agency of Canada, Surveillance and Epidemiology Division Thompson, Wendy; Public Health Agency of Canada, Surveillance and Epidemiology Division Keyword: physical activity < exercise, sedentary behaviour, sleep, adolescent, health

2 Page 1 of 30 Applied Physiology, Nutrition, and Metabolism Is adherence to the Canadian 24-hour movement behaviour guidelines for school-aged children and youth associated with improved indicators of physical, mental, and social health? Ian Janssen, a,b Karen C. Roberts, c Wendy Thompson c a School of Kinesiology and Health Studies, Queen s University, Kingston, ON b Department of Public Health Sciences, Queen s University, Kingston, ON c Surveillance and Epidemiology Division, Public Health Agency of Canada, Ottawa, ON Address correspondence to: Ian Janssen, PhD School of Kinesiology and Health Studies Queen s University Kingston, ON, K7L 3N6 Tel: (613) ext ian.janssen@queensu.ca 1

3 Page 2 of 30 ABSTRACT The Canadian 24-Hour Movement Guidelines for Children and Youth were released in These guidelines contained recommendations for moderate-to-vigorous physical activity, screen time, and sleep duration. The objectives of this study were to determine: 1) whether achieving the individual recommendations and combinations of the recommendations within the guidelines is associated with indicators of physical, mental, and social health within children and youth; 2) whether meeting the recommendation for a specific movement behaviour is associated with larger differences in physical, mental, and social health indicators by comparison to meeting the recommendations for the other specific movement behaviours; and 3) whether physical, mental, and social health indicators differ according to different combinations of the guideline recommendations achieved. To address these objectives, we studied a representative sample of over 17,000 Canadians aged years. The findings indicating that participants achieving any given recommendation had preferable scores for the health outcomes compared with participants who did not meet the recommendations. There was a doseresponse pattern between the number of recommendations achieved and the health outcomes, indicating the health outcomes improved as more recommendations were achieved. When the number of recommendations achieved was the same, there were no differences in the health outcomes. For instance, health indicators scores were not different in the group who achieved the sleep and screen time recommendations, the group who achieved sleep and moderate-to-vigorous physical activity recommendations, and the group who achieved screen time and moderate-to-vigorous physical activity recommendations. Key Words: physical activity, sedentary behaviour, sleep, adolescent, health, epidemiology 2

4 Page 3 of 30 Applied Physiology, Nutrition, and Metabolism INTRODUCTION The Canadian 24-Hour Movement Guidelines for Children and Youth were released in June of 2016 (Tremblay et al. 2016). These novel guidelines provide recommendations on the appropriate amount of moderate-to-vigorous physical activity (MVPA), sedentary behaviour (SB), and sleep that 5-17 year olds should get each day. The guidelines recognize that movement is not limited to MVPA and that the movement continuum also includes light physical activity, SB, and sleep. The guidelines appreciate that each of these movement behaviours is related to health and that they are codependent on each other (Chaput et al. 2014a, Chastin et al. 2015). The 24-Hour Movement Guidelines were developed using a rigorous and transparent process (Tremblay et al. 2016). An important part of the guideline development process was conducting four systematic reviews that formed the evidence base for the recommendations contained within the guidelines. Three of the systematic reviews focused on the influence that specific movement behaviours (e.g., sleep, physical activity, SB) have on a variety of physical, mental, and social health indicators (Carson et al. 2016, Chaput et al. 2016, Poitras et al. 2016). The fourth examined how combinations of different movement behaviours influence health indicators (Saunders et al. 2016). The primary finding from the fourth systematic review is that children and youth who have the most ideal combination of movement behaviours have better physical health outcomes than children and youth who have the least ideal combination of movement behaviours. In other words, children and youth with a High Sleep/High MVPA/Low SB combination have better physical health outcomes than children and youth with a Low sleep/low MVPA/ High SB combination. In addition, children and youth who do well in any two movement behaviours have better physical health than children and youth who do poorly in the same two movement behaviours. 3

5 Page 4 of 30 The systematic review on the health benefits of combined movement behaviours identified three key research gaps that need to be addressed to increase understanding in this topic area (Saunders et al. 2016). First, existing evidence is based on physical health indicators such as obesity. Mental and social health indicators need to be considered in future studies. Second, research has not considered whether meeting the recommendation for a specific movement behaviour has a greater influence on health than meeting the recommendation for the other movement behaviours. For instance, does meeting the MVPA recommendation influence a young person s health to a greater extent than meeting the sleep or SB recommendations? Third, while researchers have compared health indicators of children and youth with the best combination of movement behaviours (High Sleep/High MVPA/Low SB) versus children and youth with the worst combination (Low Sleep/Low MVPA/ High SB), they have not compared different intermediate combinations. Thus, it is unclear how the health of children and youth who meet recommendations for two of the three movement behaviours compares to the health of children and youth who meet recommendations for a different combination of two movement behaviours (e.g., High Sleep/High MVPA/High SB vs. High Sleep/Low MVPA/Low SB vs. Low Sleep/High MVPA/Low SB). The objective of this study was to address the aforementioned gap areas within the context of the Canadian 24-Hour Movement Guidelines for Children and Youth. Specifically, we determined: 1) whether meeting the specific recommendations of the guidelines and different intermediate combinations of the recommendations is associated with indicators of physical, mental, and social health within children and youth; 2) whether meeting recommendations for any given movement behaviour is associated with larger differences in physical, mental, and social health indicators by comparison to meeting recommendations for the other movement behaviours; and 3) whether physical, mental, and social health indicators differ according to specific intermediate combinations of the 4

6 Page 5 of 30 Applied Physiology, Nutrition, and Metabolism guideline recommendations achieved. We had the opportunity to study these objectives within a representative sample of over 17,000 Canadians aged years. MATERIALS AND METHODS Study Sample and Design The 2013/2014 cycle of the Health Behaviour in School-aged Children study (HBSC) formed the dataset for this paper. The HBSC is a cross-national study of students in grades 6-10 from 44 countries (Currie et al. 2009, Freeman et al. 2012). The present study was limited to the Canadian sample. In accordance with the international sampling protocol, grade 6-10 classes from 349 different schools were selected for participation using a weighted probability technique that ensured proportional representation based on geographical location, language of instruction, religion, and community size. With the exception of publicly funded Catholic schools, students enrolled in religious schools, private schools, special needs schools, or school on reservations were not included. Collectively, they represent <7% of Canadians of the target age (Freeman et al. 2012). Seventy seven percent of the students originally selected completed the self-reported questionnaire. The questionnaire was designed to take approximately 45 minutes to complete. Consent was obtained from students, their parents/guardians, individual schools, and school boards. Ethics approval was obtained from the Queen s University General Research Ethics Board. Of the original sample of 30,117 students, 540 (1.8%) completed a condensed questionnaire that did not include all of the items needed for this study. A further 371 (1.2%) were not within the target age range (e.g., a 9 year old in a grade 6 class). The eligible sample for the present study therefore consisted of 29,206 students aged years. A total of 7,062 participants were excluded from the analyses because they were missing or had invalid data for sleep, MVPA, and/or SB. To maximize the sample size 5

7 Page 6 of 30 for the analysis of the individual health indicators, participants were only excluded from that analysis for a specific health indicator if they were missing data for that specific health indicator. The final sample sizes for the analyses of the specific health indicators were as follows: body mass index (BMI, N = 17,951), emotional problems (N = 20,207), life satisfaction (N = 21,821), and prosocial behaviours (N = 21,586). Canadian 24-Hour Movement Behaviour Guidelines The paper that described the 24-Hour Movement Guidelines and their development provides instructions on how these guidelines should be interpreted for grouping participants in research and surveillance (Tremblay et al. 2016). These instructions indicate that the following three criteria must be met for minimal inclusion as meeting the guidelines; 1) 9 to 11 hours of uninterrupted sleep per night for those aged 5 13 years and 8 to 10 hours per night for those aged years; 2) accumulation of at least 60 minutes per day of MVPA involving a variety of aerobic activities; and 3) no more than 2 hours per day of recreational screen time (ST). The recommendations indicate that each of these three criteria should be met when averaging daily time spent in each activity across all 7 days of the week. Sleep Duration Participants were asked to report the times that they typically turned out the lights to go to sleep and woke up in the morning. There were separate questions for weekdays and weekends. We estimated their average nightly sleep duration, and then group participants based on whether or not they had a sleep duration within the recommended range ( hours/night for 6-13 year olds, hours/night for year olds). Participants whose sleep duration was less than or greater than the recommended range were not considered to have met the sleep duration recommendation. 6

8 Page 7 of 30 Applied Physiology, Nutrition, and Metabolism Moderate-to-Vigorous Physical Activity Children and youth accumulate MVPA by engaging in physical activities in class time at school such as a physical education class, organized sports and programs such as a soccer practice or dance lessons, active play such as road hockey or tag, and active transportation such as walking to school (Janssen 2014). The amount of MVPA participants did in their class time at school and in their free time, including organized sports and programs and active play, were assessed with the following items: About how many hours a week do you usually take part in physical activity that makes you out of breath or warmer than usual in your class time at school? and Outside of school hours: How many hours a week do you usually exercise in your free time so much that you get out of breath or sweat?. Response options ranged from none at all to about 7 hours. The amount of time participants used active transportation was assessed with the following items: On a typical day, the main part of your journey to school is made by. and How long does it usually take you to travel to school from your home. Participants who did not select the walking or bicycling options were considered to have accumulated 0 minutes of active transportation. For those participants that selected the walking or bicycling option, active transportation duration was determined by multiplying their school travel time by two, to account for a trips to and from school, and then by five, as there are five school days in a week. We then added together the time spent in active transportation, class time physical activities, and activities in their free time and divided this by 7 to create a daily average. Based on this average, we grouped participants into those who did ( 60 minutes/day) and did not (< 60 minutes/day) meet the MVPA recommendation. Screen Time The following items assessed the amount of time participants spent watching entertainment on a screen, playing sedentary video games, and using electronic screen devices for other purposes: How 7

9 Page 8 of 30 many hours a day, in your free time, do you usually spend watching TV, videos (including YouTube or similar services), DVDs, and other entertainment on a screen?, How many hours a day, in your free time, do you usually spend playing games on a computer, games console, tablet (like ipad), smartphone or other electronic device (not including moving or fitness games)? and How many hours a day, in your free time, do you usually spend using electronic devices such as computers, tablets (like ipad) or smartphones for other purposes (e.g., homework, ing, tweeting, Facebook, chatting, surfing the internet)? Response options ranged from none at all to about 7 or more hours a day. Questions were asked for both weekdays and weekend days. Average daily ST was estimated and participants were grouped into those who did ( 2.0 hours/day) and did not (> 2.0 hours/day) meet the ST recommendation. Body Mass Index as an Indicator of Physical Health The physical health indicator of interest for the present study is the BMI, an indicator of overweight/obesity. Obesity is highly prevalent in Canada (Janssen 2013) and is associated with a plethora of health problems such as type 2 diabetes, bone and joint disorders, sleep disorders, liver disease, and respiratory problems (Must and Strauss 1999). There is also evidence that youth with obesity have an increased risk of cardiovascular disease and mortality in adulthood, independent of their BMI as an adult (Bridger 2009). Within the questionnaire participants were asked to report their height (in inches or cm) and weight (in lbs or kg), and based on this information we calculated their BMI (kg/m 2 ). Based on the distribution of BMI within the study sample, age- and sex- specific BMI z-scores were created. Therefore, the mean and SD were was 0 and 1, respectively, and higher z-scores indicate higher BMI values. Mental and Social Health Indicators 8

10 Page 9 of 30 Applied Physiology, Nutrition, and Metabolism We examined the following mental and social health indicators: emotional problems as a proxy for mental illness, life satisfaction as a proxy for positive mental health, and prosocial behaviours as a proxy for social well-being. These mental and social health indicators were selected to capture a complete range of mental health and social well-being (Keyes et al. 2010, Freeman et al. 2012). Emotional problems. Based on underlying theory and on factor and reliability analyses, a summary emotional health problems score was constructed based on responses to nine items (Freeman et al. 2012). The first 3 items used for this score asked participants the frequency over the past six months they had the following: feeling low (depressed), feeling nervous and difficulties in getting to sleep with 5 response options ranging from rarely or never to about every day. The next item asked In the last week have you felt sad with 5 response options ranging from never to always. The remaining 5 items asked participants if the they have trouble making decisions, often wish I were someone else, often feel helpless, often feel left out of things and often feel lonely with 5 response options ranging from strongly disagree to strongly agree. Based upon the responses to these 9 items, principal component analysis with a direct oblimin rotation was used to create a summary emotional problems z-score. The reliability of this score is 0.84 (Freeman et al. 2012). Since this is a z- score, the mean was 0 and the SD was 1. Higher z-scores indicate more emotional problems. Prosocial behaviours. Prosocial behaviours refer to performing positive actions for others without being asked. Based on underlying theory and on factor and reliability analyses, a summary prosocial behaviour score, with a reliability of 0.85, was constructed based on responses to the following five items (Freeman et al. 2012): I often do favours for people without being asked, I often lend things to people without being asked, I often help people without being asked, I often compliment people without being asked, and I often share things with people without being asked. Participants rated 9

11 Page 10 of 30 each item in terms of likeness to themselves with 6 response options ranging from Definitely not like me to Definitely like me. Based upon the responses to these 5 items, principal component analysis with a direct oblimin rotation was used to create a summary prosocial behaviours z-score. The reliability of this score is 0.85 (Freeman et al. 2012). Since this is a z-score, the mean was 0 and the SD was 1. Higher z-scores indicate more prosocial behaviours. Life satisfaction. Life satisfaction was measured using the Cantril ladder, a well-established tool with good psychometric properties that measures subjective well-being and overall happiness (Cantril 1965, Atkinson 1982, Currie et al. 2009). Specifically, participants were asked to rank their current life state with the following question: Here is a picture of a ladder. The top of the ladder 10 is the best possible life for you and the bottom 0 is the worst possible life for you. In general, where on the ladder do you feel you stand at the moment?. Responses were scored from 0 to 10 and then covered into z-scores with a mean of 0 and SD of 1. Z-scores were created so that the units for life satisfaction would be the same as the units for the other health indicators. Higher z-scores indicate greater life satisfaction. Confounding Variables The following confounding variables were adjusted for in regression analyses: gender, age, family structure (single parent vs. dual parent household (McMillan et al. 2015)), ethnicity (white vs. non-white and immigration status (born in Canada, immigrated > 5 years ago, immigrated within past 5 years) (Kukaswadia et al. 2014), self-reported family affluence as a measure of socioeconomic status (low, moderate, high (McMillan et al. 2016)), frequency of smoking (non-smoker, 1-6 days per week, daily), frequency of alcohol intoxication (never, 1-9 times, 10 times), and a factor derived diet composition score that was based on the frequency of consuming sweets (candy or chocolate), potato chips, sugared 10

12 Page 11 of 30 Applied Physiology, Nutrition, and Metabolism soft drinks, and energy drinks (Janssen et al. 2006). All confounding variables were self-reported in the HBSC questionnaire. Statistical Analysis Statistical analyses were conducted in SAS version 9.4 (SAS Institute, Carry, NC) and accounted for the clustered nature of the survey data and the sample weights. Conventional descriptive statistics, such as prevalences and means, were used to describe the sample. Differences in the health indicator z- scores across the different groups were determined using the PROC SURVEYREG command and CONTRAST option. When multiple group comparisons were made, a Bonferroni correction was made to the p value used to denote statistical significance (i.e.,.05/ number of comparisons). Confounding variables were adjusted for in these regression models. RESULTS A description of selected demographic, movement behaviour, and health indicator data for the study sample is provided in Table 1. Approximately half were male and the majority were of a white ethnicity and born in Canada. Less than 3% met all three of the movement behaviour guidelines. For the emotional problems questionnaire items, less than 10% selected the response option that corresponded to the highest level of emotional problems (e.g., 6% responded that they felt low/depressed daily, 6% responded that they strongly agree that they often feel helpless). For the prosocial behaviour questionnaire items, greater than 15% selected the definitely like me response option (e.g., 29% responded that complimenting other people was definitely like them). The mean BMI, emotional problems, life satisfaction, and prosocial behaviour z-scores according to whether or not participants met recommendations for sleep duration, MVPA, and ST are shown in Table 11

13 Page 12 of Without exception, children and youth meeting each recommendation had lower BMI and emotional problems scores and higher life satisfaction and prosocial behaviour scores by comparison to children and youth not meeting that recommendation. With one exception, these differences remained significant (p<.05) after adjusting for the confounding variables and the other two movement behaviours. The one exception was for BMI z-scores, which were not different (p=.15) in participants who did and did not meet the ST guidelines after adjusting for the confounding variables, sleep, and MVPA. For each guidelines recommendation we calculated to what extent each of the health indicator z-scores differed in participants who met the recommendation by comparison to participants who did not meet the recommendation. These differences scores are illustrated in Figure 1. For BMI, emotional problems, and life satisfaction, the difference scores for sleep, MVPA, and ST were not different from each other (p>.05). For prosocial behaviours, the difference score for MVPA was greater than the difference scores for sleep and ST (p<.05). The mean health indicator z-scores according to the number of guideline recommendations met are shown in Table 3. Figure 2 illustrates the extent to which these same scores differed in participants who met one, two, or three recommendations by comparison to participants who did not meet any of the recommendations. In general, the pattern of findings in Table 3 and Figure 2 demonstrate that after controlling for confounding variables, participants meeting no recommendations had higher BMI and emotional problem scores and lower life satisfaction and prosocial behaviour scores by comparison to participants meeting one recommendation (p<.008). Similar differences were seen when comparing participants meeting one recommendation vs. participants meeting two recommendations, and when comparing participants meeting two recommendations vs. participants meeting all three 12

14 Page 13 of 30 Applied Physiology, Nutrition, and Metabolism recommendations (p<.008). The only two exceptions to this pattern were as follows. First, BMI z-scores were not different in participants meeting one vs. two recommendations (p=0.6). Second, prosocial behaviour z-scores were different in participants meeting two vs. three recommendations (p=.2). The mean health indicator z-scores based on the eight different intermediate combinations of the guideline recommendations is shown in Table 4. To reduce the likelihood of making a type I error, statistical comparisons were only made across intermediate combinations that met the same number of recommendations. That is, scores were compared across: 1) the sleep only, MVPA only, and ST only groups, and 2) the sleep + MVPA, sleep + ST, and MVPA + ST groups. As seen in Figure 3, for BMI and life satisfaction there were no significant differences across the sleep only, MVPA only, and ST only intermediate combination groups. Emotional problem scores were lower in the ST only group than in the sleep only group (p=0.008) and prosocial behaviour scores were higher in the MVPA only group than in the ST only group (p<0.001). As seen in Figure 4, for all four health indicators there were no differences across the sleep + MVPA, sleep + ST, and MVPA + ST intermediate combination groups. DISCUSSION The purpose of this study was to examine and compare the extent to which meeting the specific recommendations of the new Canadian 24-hour Movement Guidelines, and different intermediate combinations of these recommendations, is associated with indicators of physical, mental, and social health within children and youth. Our key findings are as follows. First, meeting the recommendations for sleep, MVPA, and ST on their own and in different combinations were associated with the physical, mental, and social health indicators. Second, for the most part, meeting the recommendations for sleep, MVPA, and ST influenced the health indicators to a similar extent. Third, there was a gradient or dose-response relationship between the number of movement behaviour recommendations met and 13

15 Page 14 of 30 the health indicators. Fourth, for the most part, when the number of recommendations met was the same, the health indicators were not different based on different intermediate combinations of the recommendations. Recently published systematic reviews provide convincing evidence that getting enough sleep (Chaput et al. 2016), accumulating sufficient MVPA (Poitras et al. 2016), and limiting ST (Carson et al. 2016) are associated with a variety of physical, mental, and social health indicators among school-aged children and youth. Because the recommendations within the new 24-hour Movement Behaviour Guidelines were derived from this evidence (Tremblay et al. 2016), it is not surprising that in our study the health indicator scores were more preferable in participants meeting each movement behaviour recommendation by comparison to participants who did not meet that recommendation. The novel aspect of our study was the direct comparison of the three guideline recommendations (Figure 1). Our findings suggest that meeting the recommendation for sleep is no better or worse than meeting the recommendation for MVPA or ST for three of the four health indicators examined. Meeting the recommendations for MVPA and ST also had similar effects on three of the four health indicators. It should be noted that the differences in mean health indicator scores between those meeting and not meeting a specific guideline recommendation were modest. For instance, for emotional problems the difference in the adjusted mean z-scores between the groups meeting and not meeting the recommendations were 0.24 for sleep, 0.19 for MVPA, and 0.18 for ST. Previous studies that simultaneously considered the influence of sleep, physical activity, and sedentary behaviour have found that children and youth who do well in all three of these behaviours have better health measures than children and youth who do well in fewer numbers of these behaviours (Chaput et al. 2014b, Hjorth et al. 2014, Laurson et al. 2014). Studies that have simultaneously considered any two 14

16 Page 15 of 30 Applied Physiology, Nutrition, and Metabolism movement behaviours (e.g., MVPA and SB) have made comparable observations (Laurson et al. 2008, Ekelund et al. 2012, Katzmarzyk et al. 2015). A systematic review has noted that these combined movement behaviour studies have focused on physical health outcomes, with a large emphasis on obesity measures (Saunders et al. 2016). We have extended the knowledge base by also studying indicators of mental and social health, and the patterns of observations for these health indicators were stronger and more consistent to those for BMI. Our study further adds to the literature by looking at different intermediate combinations, which has not been considered in earlier studies (Saunders et al. 2016), perhaps because of the extremely large sample size needed to allow for such comparisons. For this objective of our study we found that the intermediate combinations of movement behaviours were not particularly important for a young person s health. For example, there was no clear benefit of the High Sleep/High MVPA/High SB combination versus the High Sleep/Low MVPA/Low SB combination or the Low Sleep/High MVPA/Low SB combination (Figure 4). While the intermediate combinations themselves were not important, increasing the number of recommendations met clearly was (Figure 2). A key implication of our finding is that sleep, MVPA, and ST behaviours are important and would therefore all need to be addressed for children and youth to have optimal physical, mental, and social health. Our findings imply that all of these behaviours are of equal importance, and that for optimal health none are sufficient on their own to override a lack of success in either of the other two behaviours. The more is better message that has historically been promoted in physical activity guidelines that focus on MVPA (Tremblay et al. 2011), appears to also hold true within the context of doing better in multiple movement behaviours as there was a gradient relationship between the number of recommendations met with the health indicators. The differences in adjusted mean z-scores between the group meeting no recommendation and the group meeting all three recommendations was 0.28 for BMI, 0.64 for emotional problems, 0.53 for life satisfaction, and 0.48 for prosocial behaviours. 15

17 Page 16 of 30 These are meaningful differences at the population level as shifting the population distribution of a risk factor prevents more disease than targeting high-risk people (Rose 1985). A key strength of our study was the consideration of physical, mental and social health indicators. Another strength is the large sample size, which allowed us to look at the different intermediate combinations of the guideline recommendations. Because the HBSC is a representative study, the findings are generalizable to the Canadian population in grades While this study had many strengths, it also had some notable limitations. An important limitation is the cross-sectional design, which does not allow us to make causal inferences on the observed associations. Another limitation is the self-reported nature of the data. This would have undoubtedly led to some misclassification of the movement behaviour exposure variables, the health indicator outcome variables, and the confounding variables. The true associations could have been stronger or weaker than the observed associations, depending on whether the misclassification was differential or non-differential. Finally, a significant proportion of the study sample was not included in the analyses because of missing or incomplete data. This would have biased the findings of this etiological study if the study was underpowered after losing these participants, which it was not, or if the associations between the movement behaviours and health indicators differed in HBSC participants who were and not included in the analyses, which is unlikely. In conclusion, our findings support the recommendations contained within the new Canadian 24-hour movement behaviour guidelines for children in youth. Sleep, MVPA, and ST are each independently associated with physical, mental, and social health. The more recommendations on these movement behaviours that children and youth meet, the better their health. 16

18 Page 17 of 30 Applied Physiology, Nutrition, and Metabolism ACKNOWLEDGEMENTS The 2014 Canadian Health Behaviour in School-Aged Children study and this paper were funded by the Public Health Agency of Canada. The author was supported by a Canada Research Chair award. CONFLICTS OF INTEREST The authors report no conflicts of interest associated with this manuscript. REFERENCES Atkinson, T The stability and validity of quality of life measures. Soc Indicators Res 10: Bridger, T Childhood obesity and cardiovascular disease. Paediatr. Child Health 14(3): Cantril, H The pattern of human concern. New Brunswick, New Jersey, Rutgers University Press. Carson, V., Hunter, S., Kuzik, N., Gray, C.E., Poitras, V., Chaput, J.-P., et al Systematic review of the relationships between sedentary behaviour and health indicators in school-aged children and youth: an update. Appl. Physiol. Nutr. Metab. 41(6 Suppl 3): S240-S265. Chaput, J.P., Carson, V., Gray, C.E., Tremblay, M.S. 2014a. Importance of all movement behaviors in a 24 hour period for overall health. Int. J. Environ. Res. Public Health 11(12): doi: /ijerph Chaput, J.P., Gray, C.E., Poitras, V., Carson, V., Gruber, R., Olds, T., et al Systematic review of the relationships between sleep duration and health indicators in school-aged children and youth. Appl. Physiol. Nutr. Metab. 41(6 Suppl 3): S266-S282. Chaput, J.P., Leduc, G., Boyer, C., Belanger, P., LeBlanc, A.G., Borghese, M.M., et al. 2014b. Objectively measured physical activity, sedentary time and sleep duration: independent and combined associations with adiposity in Canadian children. Nutr. Diabetes 4: e117. doi: /nutd

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20 Page 19 of 30 Applied Physiology, Nutrition, and Metabolism Keyes, C.L., Dhingra, S.S., Simoes, E.J Change in level of positive mental health as a predictor of future risk of mental illness. Am. J. Public Health 100(12): doi: /AJPH Kukaswadia, A., Pickett, W., Janssen, I Influence of country of birth and ethnicity on body mass index among Canadian youth: a national survey. CMAJ Open, 2(3): E doi: /cmajo Laurson, K.R., Eisenmann, J.C., Welk, G.J., Wickel, E.E., Gentile, D.A., Walsh, D.A Combined influence of physical activity and screen time recommendations on childhood overweight. J. Pediatr. 153(2): doi: /j.jpeds Laurson, K.R., Lee, J. A., Gentile, D.A., Walsh, D.A., Eisenmann, J.C Concurrent Associations between Physical Activity, Screen Time, and Sleep Duration with Childhood Obesity. ISRN obesity, 2014: doi: /2014/ McMillan, R., McIsaac, M., Janssen, I Family structure as a predictor of screen time among youth. PeerJ, 3: e1048. doi: /peerj McMillan, R., McIsaac, M., Janssen, I Family Structure as a Correlate of Organized Sport Participation among Youth. Plos one, 11(2): e doi: /journal.pone Must, A., Strauss, R.S Risks and consequences of childhood and adolescent obesity. Int. J. Obes. Relat. Metab. Disord. 23 Suppl 2: S2-11. Poitras, V., Gray, C.E., Borghese, M.M., Carson, V., Chaput, J.-P., Katzmarzyk, P.T.,et al Systematic review of the relationships between objectively measured physical activity and health indicators in school-aged children and youth. Appl. Physiol. Nutr. Metab. 41(6 Suppl 3): S doi: /apnm Rose, G Sick individuals and sick populations. Int. J. Epidemiol. 14: Saunders, T.J., Gray, C.E., Poitras, V., Chaput, J.-P., Janssen, I., Katzmarzyk, P.T., et al Combinations of physical activity, sedentary behaviour and sleep: relationships with health indicators in 19

21 Page 20 of 30 school-aged children and youth. Appl. Physiol. Nutr. Metab. 41(6 Suppl 3): S283-S293. doi: /apnm Tremblay, M.S., Carson, V., Chaput, J.-P., Armstrong, T., Dinh, T., Duggan, M., et al Canadian 24- hour integrated movement behaviour guidelines for children and youth aged 5-17 years. Appl. Physiol. Nutr. Metab. 41(6 Suppl 3): S311-S327. doi: /apnm Tremblay, M.S., Warburton, D.E., Janssen, I., Paterson, D.H., Latimer, A. E., Rhodes, R.E., et al New Canadian physical activity guidelines. Appl. Physiol. Nutr. Metab. 36(1): doi: h [pii] /h

22 Page 21 of 30 Applied Physiology, Nutrition, and Metabolism Table 1. Selected descriptive characteristics of study sample Variable %(SE) Demographic details Gender, % boys 47.2 (0.9) Ethnicity, % white 77.2 (2.2) Immigration status, % Canadian born 80.6 (1.1) Movement behaviours Meet sleep duration recommendation, % yes 65.3 (0.8) Meet physical activity recommendation, % yes 33.3 (1.3) Meet screen time recommendation, % yes 8.0 (0.2) Meet none of the three recommendations, % yes 21.4 (0.7) Meet any one recommendation, % yes 51.1 (0.8) Meet any two recommendations, % yes 24.9 (0.9) Meet all three recommendations, % yes 2.6 (0.2) Selected health indicators and variables Obese, % yes 5.2 (0.3) Felt low (depressed),% about every day 6.4 (0.3) Felt nervous, % about every day 9.9 (0.3) Often feel helpless, % strongly agree 5.9 (0.3) Often do favours, % definitely like me 17.0 (0.8) Often share things, % definitely like me 19.6 (0.6) Often compliment people, % definitely like me 28.9 (0.7) Life satisfaction, % rated 8 or higher 55.0 (0.8) Data presented as prevalence (standard error) 21

23 Page 22 of 30 Table 2. Differences in the physical, mental, and social health indicators according to whether or not participants met the individual recommendations contained with the 24-hour Movement Behaviour Guidelines. Meet guideline recommendation BMI Z-Score Emotional Problems Z-Score Life Satisfaction Z-Score Prosocial Behaviour Z-Score Unadjusted Adjusted Unadjusted Adjusted Unadjusted Adjusted Unadjusted Adjusted Mean (SE) Mean (SE) a Mean (SE) Mean (SE) a Mean (SE) Mean (SE) a Mean (SE) Mean (SE) a Sleep duration No.09(.03).24(.08).19(.02).53(.04) -.20(.03) -.64(.05) -.04(.02) -.16(.06) Yes -.02(.03) b.05(.07) b -.14(.02) b.29(.04) b.09(.01) b -.44(.06) b.10(.02) b -.06(.06) b Physical activity No.04(.02).22(.07).09(.02).50(.04) -.12(.02) -.64(.05) -.05(.02) -.26(.06) Yes -.03(.03) b.17(.08) b -.22(.02) b.31(.04) b.19(.02) b -.44(.06) b.23(.02) b -.04(.06) b Screen time No.02(.02).22(.07).00(.02).50(.03) -.03(.02) -.62(.05).03(.02) -.16(.05) Yes -.15(.05) b.16(.08) -.32(.04) b.32(.05) b.26(.04) b -.46(.06) b.22(.04) b -.06(.07) b Data presented as means (standard error) a Adjusted for gender, age, ethnicity, family structure, immigration status, family affluence, smoking, alcohol intoxication, diet composition and adherence to the other two guidelines components. For example, sleep duration was also adjusted for moderate-to-vigorous physical activity and screen time. b significantly different from No group (p<0.05). 22

24 Page 23 of 30 Applied Physiology, Nutrition, and Metabolism Table 3. Differences in the physical, mental, and social health indicators according to the number of movement behaviour guidelines met. # of guideline BMI Z-Score Emotional Problems Z-Score Life Satisfaction Z-Score Prosocial Behaviour Z-Score recommendations Unadjusted Adjusted Unadjusted Adjusted Unadjusted Adjusted Unadjusted Adjusted met Mean (SE) Mean (SE) a Mean (SE) Mean (SE) Mean (SE) Mean (SE) Mean (SE) Mean (SE) None.15(0.04) b.32(.08) b.32(.03) b.72(.04) b -.33(.03) b -.82(.05) b -.15(.03) b -.37(.05) b One.00(.03) c.20(.07) c -.01(.02) c.48(.03) c -.03(.02) c -.62(.05) c.02(.02) c -.20(.05) c Two.00(.04) c.18(.07) c -.29(.02) d.30(.04) d.25(.02) d -.43(.05) d.25(.03) d -.02(.06) d All three -.27(.07) d.04(.09) d -.57(.06) e.08(.07) e.45(.07) e -.29(.09) e.38(.07) d.11(.09) d Data presented as means (standard error) a Adjusted for gender, age, ethnicity, family structure, immigration status, family affluence, smoking, alcohol intoxication, and diet composition. b,c,d,e group means that do not have the same letters are significantly different from each other (p<.008). 23

25 Page 24 of 30 Table 4. Differences in the physical, mental, and social health indicators according to combination of movement behaviour guidelines met. Combination of guideline recommendations met BMI Z-Score Emotional Problems Z-Score Life Satisfaction Z-Score Prosocial Behaviour Z-Score Unadjusted Adjusted Unadjusted Adjusted Unadjusted Adjusted Unadjusted Adjusted Mean (SE) Mean (SE) a Mean (SE) Mean (SE) Mean (SE) Mean (SE) Mean (SE) Mean (SE) None.15(.04).32(.07).31(.03).71(.04) -.33(.03) -.82(.05) -.15(.03) -.38(.05) Sleep duration.00(.03).19(.06) -.01(.02) b.47(.04) b -.03(.02) -.63(.05) -.02(.03) -.26(.05) only Physical activity only.00(.04).18(.08) -.03(.04).50(.04) -.00(.03) -.61(.05).16(.03) b -.03(.06) b Screen time only.17(.15).43(.16).17(.09).69(.09).04(.09) -.57(.09) -.17(.10) -.43(.11) Sleep duration (.04).19(.07) -.29(.03).30(.04).26(.02) -.42(.05).25(.03).03(.06) physical activity Sleep duration (.10).12(.11) -.33(.06).26(.07).23(.06) -.45(.07).24(.07) -.05(.09) screen time Physical activity (.11).17(.15) -.28(.10).31(.10).13(.09) -.53(.10).29(.10).08(.12) screen time All three -.26(.07).04(.09) -.57(.05).08(.07).45(.07) -.29(.10).38(.07).10(.09) Data presented as means (standard error) a Adjusted for gender, age, ethnicity, family structure, immigration status, family affluence, smoking, alcohol intoxication, and diet composition. b significantly different from screen time only group (p 0.008). 24

26 Page 25 of 30 Applied Physiology, Nutrition, and Metabolism Figure Legends Figure 1. Adjusted differences in body mass index, emotional problems, life satisfaction, and prosocial behaviour z-scores in participants who met guideline recommendations for sleep (square symbols), moderate-to-vigorous physical activity (circle symbols), and screen time (diamond symbols). Participants who did not meet the recommendation for that specific guideline served as the referent group for the difference score calculations. These difference scores were adjusted for gender, age, ethnicity, family structure, ethnicity, immigration status, family affluence, smoking, drunkenness, diet composition and adherence to the other two guidelines components (e.g., sleep duration was adjusted for moderate-to-vigorous physical activity and screen time). The error bars represent 95% confidence intervals. * significant difference between the group meeting the recommendation versus the group not meeting the recommendation (p<0.05). Figure 2. Adjusted differences in body mass index, emotional problems, life satisfaction, and prosocial behaviour z-scores in participants who met no guideline recommendations (triangle symbol), one guideline recommendation (square symbols), two guideline recommendations (circle symbols), and all three guideline recommendations (diamond symbols. Participants who met none of the guideline recommendations served as the referent group for the difference score, and therefore the difference scores for the group who met no guideline recommendations was set at 0. These difference scores were adjusted for gender, age, ethnicity, family structure, ethnicity, immigration status, family affluence, smoking, drunkenness, and diet composition. The error bars represent 95% confidence intervals. * significant difference versus the group meeting none of the recommendations (p<0.05). significant difference versus the groups meeting none or one of the recommendations (p<0.05). significant difference versus the groups meeting none, one, or two of the recommendations (p<0.05). 25

27 Page 26 of 30 Figure 3. Adjusted differences in body mass index, emotional problems, life satisfaction, and prosocial behaviour z-scores in participants who met guideline recommendations for sleep only (square symbols), moderate-to-vigorous physical activity only (circle symbols), and screen time only (diamond symbols). Participants met none of the three guideline recommendations served as the referent group for the difference score calculations. These difference scores were adjusted for gender, age, ethnicity, family structure, ethnicity, immigration status, family affluence, smoking, drunkenness, and diet composition. The error bars represent the 95% confidence intervals. * difference for Screen Time Only is significantly greater than difference for Sleep Only (p=0.008). difference for Physical Activity Only is significantly greater than difference for Screen Time Only (p<0.05). Figure 4. Adjusted differences in body mass index, emotional problems, life satisfaction, and prosocial behaviour z-scores in participants who met guideline recommendations for sleep + moderate-tovigorous physical activity (sleep + MVPA, square symbols), sleep + screen time (sleep + ST, circle symbols), and moderate-to-vigorous physical activity + screen time (MVPA + ST, diamond symbols). Participants who met none of the three guideline recommendations served as the referent group for the difference score calculations. These difference scores were adjusted for gender, age, ethnicity, family structure, ethnicity, immigration status, family affluence, smoking, drunkenness, and diet composition. The error bars represent the 95% confidence intervals. 26

28 Page 27 of 30 Applied Physiology, Nutrition, and Metabolism Figure 1 125x87mm (600 x 600 DPI)

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