Exploring school neighborhood food environment of Norwegian adolescents

Abstract

Background: Adolescent overweight and obesity rates are increasing in Norway. Adolescents spend a lot of time at school and the school neighborhood food environment could affect adolescents’ dietary behavior and development of overweight and obesity. Access to unhealthy foods at school can contribute to a high intake of unhealthy food items and beverages during the school day. The availability of food sales outlets in the school neighborhoods is one environmental determinant that may be of great importance for adolescents’ dietary behavior. One of the first steps when investigating a neighborhood food environment is to obtain descriptive data of the presence of food sales outlets and the availability of food items. The knowledge of the neighborhood food environment and the effect on dietary habits are inconclusive and based on research from countries where the food environments may not be representative for Norway. Consequently, there is a need for research from Norwegian school neighborhood food environments. An instrument for investigating adolescents’ food environment by measuring availability and linear shelf space of food items in food sales outlets in school neighborhoods was developed and evaluated within a research project in Oslo in 2009. This thesis is the continuation of that previous research.

Objective: To describe the availability (if food is present or not) and accessibility (measured in linear shelf space or number of varieties) of food items in food sales outlets around primary and lower secondary schools in eastern Norway, and to explore variation by the schools socio-economic position and possible associations with schools’ mean frequency of the intake per week of selected food items by 7th grade pupils.

Design: Cross sectional data from the HEIA-study (involving primary schools) collected in May 2009 and from HEIA II (involving lower secondary schools) are analyzed in this thesis to answer the objectives and aims.

Methods and sample: There were 37 primary schools and 36 lower secondary schools in the samples. Food sales outlets were identified in the neighborhoods of the schools by using internet-based map services and by physically checking the neighborhood on the day of data collection. An observational form designed for direct observation of food sales outlets was used to measure availability and accessibility of 16 food items and beverages. Descriptive data and comparative data between the two types of schools are presented. Data to determine socio-economic position of each school were collected by questionnaire from 37 and 32 principals from the primary- and lower secondary schools, respectively. Social disparities in the food environment and its food sales outlets were investigated in the sample. Data on the adolescents’ diet were collected by questionnaire from 945 7th graders (primary school). Associations between the school mean frequency of the intake per week of seven selected food items and both the number of food sales outlets in the school neighborhood and the accessibility of the seven selected food items were analyzed by One-way ANOVA and correlation analyses.

Results: Food sales outlets were found around 25 (68%) of the primary schools and 28 (78%) of the lower secondary schools. The number of outlets in each school neighborhood was at its highest nine but with a mean of 1.6 and 1.8 (no significant difference) in primary- and lower secondary schools. The total number of outlets around each school type (primary- vs. lower secondary schools) was similar (60/65). The food sales outlets were supermarkets, kiosks and gas stations with a frequency of occurrence in the mentioned order. Across all types of food sales outlets, the most available food items were those defined as unhealthy. The accessibility of soft drinks with sugar was significantly higher, and another nine food items of the 13 investigated was non-significantly higher, in the neighborhoods of lower secondary schools compared to primary schools. Schools of lower socio-economic position (both primary- and lower secondary schools) had non-significantly higher number of food sales outlets in the neighborhood, higher accessibility of the majority of the food items and in addition a trend of more kiosks and fewer supermarkets, compared to schools of higher socio-economic position. There was a significant lower school mean frequency of raw vegetables intake per week in schools with more than one food sales outlet in the neighborhood compared to school neighborhoods with only one or no food sales outlet. This pattern was also found as a border-line significant negative correlation between school mean frequency of raw vegetables intake per week and the accessibility in the school neighborhoods.

Conclusions: Food sales outlets were present in approximately three quarters of the school neighborhoods but the number of food sales outlets in each school neighborhood varied and there were no clear difference between primary- and lower secondary schools. The accessibility of soft drinks with sugar was significantly higher, and another nine food items of the 13 investigated was non-significantly higher, in the neighborhoods of lower secondary schools compared to primary schools. Non-significant school neighborhood disparities related to socio-economic position was present. The food environment and its food sales outlets in Norwegian school neighborhoods need to be investigated more as a potential environmental factor that may affect dietary behavior and body weight of adolescents. Future studies should investigate adolescents’ use of food sales outlets and/or store size adjusted analyses with ratio of healthy/unhealthy food items as well as social disparities in this.