Consumption habits of school canteen and non-canteen users among Norwegian young adolescents: a mixed method analysis

BACKGROUND: Food/drinks available to adolescents in schools can influence their dietary behaviours, which once established in adolescence, tend to remain over time. Food outlets’ influence near schools, known to provide access to unhealthy food/drinks, may also have lasting effects on consumption behaviours. This study aimed to gain a better understanding of the consumption habits of adolescents in the school arena by comparing different personal characteristics and purchasing behaviours of infrequent and regular school canteen users to those never or seldom using the canteen. METHODS: A convergent mixed methods design collected qualitative and quantitative data in parallel. A cross-sectional quantitative study including 742 adolescents was conducted, with data collected at schools via an online questionnaire. Focus group interviews with students and interviews with school administrators formed the qualitative data content. Quantitative data were analysed using descriptive statistics and logistic regression; thematic content analysis was used to analyse qualitative data. RESULTS: Sixty-seven percent of adolescents reported never/rarely using the school canteen (NEV), whereas 13% used it ≥2 times per week (OFT). When the two groups were compared, we found a significantly higher proportion of the NEV group were female, having parents with a high education, and with a high self-efficacy, whilst a significantly higher proportion of the OFT group consumed salty snacks, baked sweets, and soft-drinks ≥3 times per week, and breakfast at home < 5 days in the school week. The OFT group had significantly higher odds of purchasing food/drink from shops near school during school breaks and before/after school compared to the NEV group (adjusted odds ratio (aOR) = 1.80, 95% CI 1.07–3.01, and aOR = 3.61, 95% CI 2.17–6.01, respectively). The interviews revealed most students ate a home packed lunch, with the remainder purchasing either at the school canteen or at local shops. CONCLUSIONS: Students using the canteen often are frequently purchasing snacks and sugar-soft drinks from shops near school, most likely owing to availability of pocket money and an emerging independence. School authorities must focus upon satisfying canteen users by providing desirable, healthy, and affordable items in order to compete with the appeal of local shops. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12887-018-1299-0) contains supplementary material, which is available to authorized users.