title: Health behaviours, body weight and self-esteem among grade five students in Canada.
abstract: OBJECTIVE
  This study sought to identify the principal components of self-esteem and the health behavioural determinants of these components among grade five students.
  
  
  METHODS
  We analysed data from a population-based survey among 4918 grade five students, who are primarily 10 and 11 years of age, and their parents in the Canadian province of Nova Scotia. The survey comprised the Harvard Youth and Adolescent Questionnaire, parental reporting of students' physical activity (PA) and time spent watching television or using computer/video games. Students heights and weights were objectively measured. We applied principal component analysis (PCA) to derive the components of self-esteem, and multilevel, multivariable logistic regression to quantify associations of diet quality, PA, sedentary behaviour and body weight with these components of self-esteem.
  
  
  RESULTS
  PCA identified four components for self-esteem: self-perception, externalizing problems, internalizing problems, social-perception. Influences of health behaviours and body weight on self-esteem varied across the components. Better diet quality was associated with higher self-perception and fewer externalizing problems. Less PA and more use of computer/video games were related to lower self-perception and social-perception. Excessive TV watching was associated with more internalizing problems. Students classified as obese were more likely to report low self- and social-perception, and to experience fewer externalizing problems relative to students classified as normal weight.
  
  
  CONCLUSIONS
  This study demonstrates independent influences of diet quality, physical activity, sedentary behaviour and body weight on four aspects of self-esteem among children. These findings suggest that school programs and health promotion strategies that target health behaviours may benefit self-esteem in childhood, and mental health and quality of life later in life.
authors.affiliation: School of Health and Human Performance, Dalhousie University, Halifax, NS Canada.
authors.forename: Xiuyun
authors.initials: X
authors.lastname: Wu
authors.affiliation: School of Health and Human Performance, Dalhousie University, Halifax, NS Canada ; IWK Health Centre, Halifax, NS Canada.
authors.forename: Sara F L
authors.initials: SF
authors.lastname: Kirk
authors.affiliation: School of Public Health, University of Alberta, 350 University Terrace, 8303 - 112 Street, Edmonton, AB T6G 2T4 Canada.
authors.forename: Arto
authors.initials: A
authors.lastname: Ohinmaa
authors.affiliation: School of Public Health, University of Alberta, 350 University Terrace, 8303 - 112 Street, Edmonton, AB T6G 2T4 Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Veugelers
keywords: Children; Diet quality; Mental health; Physical activity; Sedentary behaviour; Self-esteem