Mediators of parental educational differences in the intake of carbonated sugar-sweetened soft drinks among adolescents, and the moderating role of neighbourhood income

BACKGROUND: Existing evidence suggests that the intake of sugar-sweetened beverages (SSB) among adolescents remains a public health concern and that socioeconomic differences in intake exist. Tackling these challenges requires identifying the factors associated with SSB intake and the mediators of socioeconomic differences in SSB intake among adolescents. Thus, this study aimed to explore (i) factors at different levels of the ecological model associated with the intake of carbonated soft drinks with added sugar (hereafter called soft drinks), (ii) mediators of the association between parental education and the intake of soft drinks(iii) whether neighbourhood income moderates the indirect effect of parental education on adolescents’ soft drink intake through potential mediators. METHODS: Data from 826 7(th) graders in Oslo, Norway, who participated in the TACKLE cross-sectional study conducted in 2020 were used. The association between factors at the individual, interpersonal and neighbourhood food environment levels and the intake of soft drinks among adolescents was assessed, as well as the mediating roles of these factors for the differences in intake by parental education, using multiple logistic regression and mediation analysis, respectively. Moderated mediation analyses were used to explore whether an indirect effect of parental education on adolescents' soft drink intake through potential mediators varies across neighbourhood income areas. RESULTS: Higher perceived accessibility of SSB at home, increased parental modelling for SSB intake, and increased frequency of food/drink purchased from the neighbourhood store were associated with a higher intake of soft drinks among adolescents and mediated the differences in intake by parental education. Neighbourhood food environment factors were neither statistically significantly associated with adolescents’ higher intake of soft drinks nor explained the differences in intake by parental education. Moderated mediation analysis showed that the mediating effect of perceived accessibility of SSB at home on the association between parental education and adolescent soft drink intake was stronger among those living in low neighbourhood income. CONCLUSIONS: Our study identified modifiable factors at the intrapersonal level (perceived accessibility of SSB at home and frequency of food/drink purchased from neighbourhood shops) and interpersonal levels (parental modelling for SSB intake) associated with a higher intake of soft drinks among adolescents and mediated the differences in the intake by parental education. The modifiable factors identified in this study could be targeted in public health initiatives among adolescents aimed at reducing the intake of soft drinks and the related differences by parental education.