title: Children's and adolescents' snacking: interplay between the individual and the school class.
abstract: OBJECTIVE
  In schools, perceived norms of classmates facilitate but can also inhibit unhealthy food intake in children and adolescents. However, the role of actual class behaviors and attitudes is less established. Thus, the present study examined classmates' actual eating behavior and food preferences in relation to actual food intake. In addition, it tested whether these normative effects are facilitated by corresponding individual and class food preferences or a positive social self-concept.
  
  
  METHODS
  The food preferences, social self-concept, and unhealthy snacking frequency of 734 Finnish, 829 German, and 555 Romanian children and adolescents (aged 8-19) from 127 school-classes were assessed.
  
  
  RESULTS
  Multilevel analysis at individual and class level showed that classmates shared similar snacking habits (14.7% variance). Moreover, the unhealthy food preference of a school-class was associated with its collective snacking [[Formula: see text], p < 0.001, PRV = 0.32). This effect was facilitated by individual, unhealthy food preferences [[Formula: see text], p < 0.001, PRV = 0.57] and a positive social self-concept [[Formula: see text], p = 0.015, PRV = 0.12].
  
  
  CONCLUSIONS
  Actual class norms are related to children's and adolescents' eating, but their impact depends on individual differences in preferences and social self-concept.
authors.affiliation: Department of Psychology, University of Konstanz Konstanz, Germany.
authors.forename: Helge
authors.initials: H
authors.lastname: Giese
authors.affiliation: Department of Psychology, Babeş-Bolyai University Cluj-Napoca, Romania.
authors.forename: Diana
authors.initials: D
authors.lastname: Tãut
authors.affiliation: Department of Alcohol, Drugs and Addiction, National Institute for Health and Welfare Helsinki, Finland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Ollila
authors.affiliation: Department of Psychology, Babeş-Bolyai University Cluj-Napoca, Romania.
authors.forename: Adriana S
authors.initials: AS
authors.lastname: Baban
authors.affiliation: Department of Alcohol, Drugs and Addiction, National Institute for Health and Welfare Helsinki, Finland.
authors.forename: Pilvikki
authors.initials: P
authors.lastname: Absetz
authors.affiliation: Department of Psychology, University of Konstanz Konstanz, Germany.
authors.forename: Harald T
authors.initials: HT
authors.lastname: Schupp
authors.affiliation: Department of Psychology, University of Konstanz Konstanz, Germany.
authors.forename: Britta
authors.initials: B
authors.lastname: Renner
keywords: adolescents; eating; food preference; self-concept; snack intake; social environment; social norm