title: Associations between sleep patterns and lifestyle behaviors in children: an international comparison.
abstract: OBJECTIVE
  Although evidence is accumulating on the importance of a good night's sleep for healthy eating and activity behaviors, existing research has mainly been conducted in high-income, developed countries with limited sociocultural variability. This study is the first to examine the associations between sleep patterns and lifestyle behaviors in children from 12 countries in five major geographic regions of the world.
  
  
  METHODS
  This observational, multinational cross-sectional study included 5777 children aged 9-11 years from sites in Australia, Brazil, Canada, China, Colombia, Finland, India, Kenya, Portugal, South Africa, the United Kingdom and the United States. Nocturnal sleep duration (hours per night), sleep efficiency (%) and bedtime (h:min) were monitored over 7 consecutive days using an accelerometer. Lifestyle behaviors included moderate-to-vigorous physical activity (MVPA), total sedentary time (SED), self-reported screen time (ST) and healthy/unhealthy diet patterns (HDP/UDP). Multilevel modeling analyses were used to account for the hierarchical nature of the data.
  
  
  RESULTS
  Overall, participants averaged 8.8 (s.d. 0.9) hours of sleep with 96.2% (s.d. 1.4) sleep efficiency and a mean bedtime of 2218 hours. After adjustment for age, sex, highest parental education and BMI z-score, results showed that (i) sleep duration was negatively associated with MVPA, SED and UDP score; (ii) sleep efficiency was negatively associated with MVPA and UDP score, and positively associated with SED; and (iii) later bedtime was positively associated with SED, ST and UDP score, and negatively associated with MVPA and HDP score. Results using categories of sleep patterns were consistent with the linear associations. Results also revealed that associations between sleep patterns and MVPA, SED and ST were significantly different between study sites, with stronger associations in high-income countries compared with low/middle-income countries.
  
  
  CONCLUSIONS
  Sleep characteristics are important correlates of lifestyle behaviors in children. Differences between countries suggest that interventions aimed at improving sleep and lifestyle behaviors should be culturally adapted.
authors.affiliation: Healthy Active Living and Obesity Research Group, Children's Hospital of Eastern Ontario Research Institute , Ottawa, Ontario, Canada.
authors.forename: J-P
authors.initials: JP
authors.lastname: Chaput
authors.affiliation: Pennington Biomedical Research Center , Baton Rouge, LA, USA.
authors.forename: P T
authors.initials: PT
authors.lastname: Katzmarzyk
authors.affiliation: Healthy Active Living and Obesity Research Group, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada; University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: A G
authors.initials: AG
authors.lastname: LeBlanc
authors.affiliation: Healthy Active Living and Obesity Research Group, Children's Hospital of Eastern Ontario Research Institute , Ottawa, Ontario, Canada.
authors.forename: M S
authors.initials: MS
authors.lastname: Tremblay
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, LA, USA; Department of Exercise Science, University of Syracuse, Syracuse, NY, USA.
authors.forename: T V
authors.initials: TV
authors.lastname: Barreira
authors.affiliation: Pennington Biomedical Research Center , Baton Rouge, LA, USA.
authors.forename: S T
authors.initials: ST
authors.lastname: Broyles
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki , Helsinki, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Fogelholm
authors.affiliation: Pennington Biomedical Research Center , Baton Rouge, LA, USA.
authors.forename: G
authors.initials: G
authors.lastname: Hu
authors.affiliation: St. Johns Research Institute , Bangalore, India.
authors.forename: R
authors.initials: R
authors.lastname: Kuriyan
authors.affiliation: St. Johns Research Institute , Bangalore, India.
authors.forename: A
authors.initials: A
authors.lastname: Kurpad
authors.affiliation: Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, University of Cape Town , Cape Town, South Africa.
authors.forename: E V
authors.initials: EV
authors.lastname: Lambert
authors.affiliation: Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, University of Cape Town , Cape Town, South Africa.
authors.forename: D E
authors.initials: DE
authors.lastname: Rae
authors.affiliation: Alliance for Research in Exercise Nutrition and Activity (ARENA), School of Health Sciences, University of South Australia , Adelaide, South Australia, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Maher
authors.affiliation: CIFI2D, Faculdade de Desporto, University of Porto , Porto, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Maia
authors.affiliation: Centro de Estudos do Laboratório de Aptidão Física de São Caetano do Sul (CELAFISCS) , Sao Paulo, Brazil.
authors.forename: V
authors.initials: V
authors.lastname: Matsudo
authors.affiliation: Department of Recreation Management and Exercise Science, Kenyatta University , Nairobi, Kenya.
authors.forename: V
authors.initials: V
authors.lastname: Onywera
authors.affiliation: School of Medicine Universidad de los Andes , Bogota, Colombia.
authors.forename: O L
authors.initials: OL
authors.lastname: Sarmiento
authors.affiliation: Department for Health, University of Bath , Bath, UK.
authors.forename: M
authors.initials: M
authors.lastname: Standage
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, LA, USA; Department of Kinesiology, University of Massachusetts Amherst, Amherst, MA, USA.
authors.forename: C
authors.initials: C
authors.lastname: Tudor-Locke
authors.affiliation: Tianjin Women's and Children's Health Center , Tianjin, China.
authors.forename: P
authors.initials: P
authors.lastname: Zhao
authors.affiliation: Alliance for Research in Exercise Nutrition and Activity (ARENA), School of Health Sciences, University of South Australia , Adelaide, South Australia, Australia.
authors.forename: T
authors.initials: T
authors.lastname: Olds