Does the physical food environment in secondary school influence students’ social norm perceptions regarding healthy dietary choices? – An exploratory study in the Netherlands

Creating a healthy food environment in secondary schools has the potential to communicate social norms regarding healthy dietary choices. This study explored the relationship between the schools' food environment and perceived descriptive (what others do) and injunctive (what others approve) norms regarding healthy dietary choices among adolescents. An exploratory (quasi-experimental) study was conducted in 23 Dutch schools, differing between three arms based on implementation degree of a Healthy School Canteen Program: limited, moderate or sustainable. Students (n = 1004) completed a questionnaire about descriptive and injunctive norms regarding water, fruit/vegetables, snacks, sugar-containing beverages, brown/whole wheat bread. Multi-level analyses were conducted (two-level hierarchical data structure). Compared to limited implementation, students in schools with moderate implementation indicated less favorable norm perceptions with (a) lower descriptive norm scores regarding water (-.30, 95 % CI [-.47; -.12]), (b) lower injunctive norm scores regarding fruit/vegetables (-.29, 95 % CI [-.49; -.10]) and water (-.34, 95 % CI [-.49; -.20]), and (c) higher injunctive norm scores regarding sugar containing beverages (.17, 95 % CI [.02; .32]). No significant differences were observed between students in schools with sustainable implementation and limited implementation. Compared to sustainable implementation, students in schools with moderate implementation indicated less favorable injunctive norm perceptions regarding fruit/vegetables (-.28, 95 % CI [-.47; -.08] and water (-.26, 95 % CI [-.41; -.12]). This study illustrates the complex interplay between perceived social norms regarding healthy dietary choices and efforts to create a healthy food environment. Future research should examine how social norms evolve over time within schools, taking into account their unique context.