Weight Status and BMI-Related Traits in Adolescent Friendship Groups and Role of Sociodemographic Factors: The European IDEFICS/I.Family Cohort

Abstract

<b><i>Background:</i></b> During adolescence, health behaviors and weight status are increasingly influenced by friendship and peer networks. This paper examines resemblances in weight-related characteristics and how they differ by sociodemographic factors. <b><i>Methods:</i></b> Over 3,000 friendships were reported by 1,603 adolescents, aged 11–16 years, who participated in the school-based I.Family study in 6 European countries. Each “source child” named 1–10 friends for whom standardized weight-related traits were available in the same survey. The mean value of the friends’ traits weighted by time spent together was calculated, and related to the source child’s trait. Country, age and sex of the source child, parental education, and immigrant background were considered for confounding and moderation. <b><i>Results:</i></b> Source children’s <i>z</i>-scores of body fat percent and BMI were positively associated with their friends’ characteristics, in particular if they had highly educated parents. Positive associations were also found regarding the frequency of fast-food consumption, impulsivity, screen time, preference for sugar-sweetened foods, and hours spent in sports clubs, in increasing order of effect size. Additionally, correlations were observed between friends’ cognitive and school functioning and being bullied. No associations were seen for a preference for high-fat foods, weight concerns, and health-related quality of life. Finally, parental education and immigrant background were associated between friends in all countries except Sweden, where no associations were observed. <b><i>Conclusion:</i></b> Adolescent friends shared a number of weight-related characteristics. For weight measures per se, positive associations with friends’ characteristics were only observed in adolescents with high parental education. Associations regarding energy-balance behaviors and indicators of school-related well-being did not differ by parental education. Parental education and immigrant background correlated positively in friends in most countries showing that social aggregation is already occurring in adolescence. The wide spectrum of friendship associations in weight-related traits and behaviors suggests that health promotion initiatives in adolescents should be directed towards peer groups in both school-related and leisure-time environments. <b><i>ISRCTN Registry:</i></b> Pan-European IDEFICS/I.Family children cohort (ID ISRCTN62310987; https://doi.org/10.1186/ISRCTN62310987).

Changing genetic architecture of body mass index from infancy to early adulthood: an individual based pooled analysis of 25 twin cohorts

“…Thus, this new genetic component can reflect the changing interaction between new environments, such as school and participation in leisure time activities, and the genetic background of the child. This is suggested, for example, by the correlations in eating behavior and physical activity between friends in childhood and adolescence [ 36 ]. For eating behavior, there is also some direct evidence for this since the polygenic risk score of BMI was found to be associated with increasing tendency of overeating over childhood measured by parental worries [ 37 ].…”

Qualidade de vida de crianças e adolescentes praticantes de esportes: uma revisão sistemática

“…Mehlig et al 23 , ao avaliarem pares de amigos adolescentes, sugerem que o IMC e a gordura corporal possuem um componente socioeconômico e as associações entre amigos foram mais fortes naqueles com alta escolaridade dos pais ou responsáveis. Ainda entre os amigos, a correlação mais forte indicou a participação em clubes esportivos, tempo de tela e ser intimidado.…”

Association of Peer Network with Childhood Obesity in DECIDE-Children Program

“…However, our childhood-obesity intervention program focused on the individual, family and school environment. In addition, social relationships were assessed with advice seeking [24] or posts, comments and reactions [25] within adults, while we assessed peer relations with friendship nominations, which are usually used among children [26,27]. Children with higher centrality or popularity benefited more from the intervention programs, possibly because they were provided with more opportunities to gain peer support, had a better sense of belonging to the class, and were more likely to get involved in intervention programs and to be role models for other children.…”