This study showed that food environments around schools in Flanders were generally unhealthy with children having increasingly easier access to unhealthy food retailers such as convenience stores and fast-food, takeaway and delivery outlets. In addition, traditional stores such as bakeries, greengrocers and stores that sell animal products around schools declined over a 12 year period. They were replaced by full service restaurants, convenience stores, fast-food, takeaway and delivery outlets and confectionary stores which significantly increased over the same time period. These changes probably reflect a broader change in the food landscape in Flanders and are similar to results found in the Netherlands (28). The differences in indicator values between primary- and secondary schools are likely because primary schools are often located in semi-urban areas while most secondary schools are built in more dense, urban areas. Hence the density of food retailers around secondary schools is higher and walking distances are shorter than the food environments around primary schools.
Food environments near schools with a higher proportion of pupils from lower socio-economic backgrounds were found to be more unhealthy. This gradient was most pronounced for primary schools and remains after correcting for the level of urbanization. Students from these schools often come from impoverished families that lack knowledge about a healthy nutritious diet and therefor are extra vulnerable to succumb to the allure of unhealthy food environments (11, 17). The reason that food environments near these schools were more unhealthy is likely due to supply and demand effects. Because children from impoverished families often eat more unhealthy at home, they are also more likely to eat less healthy outside their home environment (29).
Food retailers that offer unhealthy food will be drawn more to the schools where these children go to (11), giving them plenty of opportunity to continue the diet they are used to at home, thus creating a vicious cycle.
A significant positive association was found between the food environment near schools and the mean BMI and % of children that is overweight for children < 6 years and 6–12 years but not for children 13–14 years and 15–18 years. Children < 6 years and 6–12 years generally commute to their school under parental supervision and cannot leave the school during lunch break. On a first glance they interact less with the food environment near their school than older children who often can leave the school perimeter during lunch break and are more independent and free to determine their own food choices. Research however has shown that solely being exposed to an unhealthy food environment can lead to a more unhealthy diet (30, 31). Young children are very susceptible to marketing and merely passing through an unhealthy food environment twice a day can lead them to craving more sugary snacks and/or fatty foods, influencing their parents’ purchasing behavior. Older children (13–14 years and 15–18 years) on the other hand, are much more mobile and are not necessarily restricted to the food environment near their school, but interact with many more different food environments. Around this age, they often experience a growth spurt meaning that an unhealthy diet won’t necessarily show in their weight status right away but might create dietary habits that can lead to excess weight later in life. Previous research has shown that a high BMI and an increased prevalence of cardio metabolic risk factors such as high levels of LDL cholesterol or elevated blood pressure are not always correlated (32).
Possible measures to improve the food environment around schools that local municipalities can take are to limit the number of unhealthy outlets or forbid the establishment of new unhealthy outlets near a school. It is crucial that the Flemish government revises local planning- and zoning policies to give local policymakers the appropriate legal instruments.
Examples from other countries are ubiquitous: For example since the early 2010’s, several districts in London have established exclusion zones around target locations such as local centers, parks and schools, banning hot food takeaways in these zones completely (33). In total 165 (50.5%) of local government areas in England have a specific policy targeting fast-food outlets, of which 56 (34.1%) are health focused (34). In Korea, Green Food Zones were created in 2009 within a 200m perimeter around schools to construct a safe and sanitary food environment (35). The Green Food Zones are managed by supervisors and the sale of low quality food for children was banned. In 2008, Los Angeles implemented a one year moratorium on opening or expanding fast-food outlets in the South region (36).
Local authorities can also oblige unhealthy outlets to offer a minimum amount of healthy options at a lower price than the unhealthy ones. Another option is to limit opening hours of unhealthy food outlets before- and after school hours. Governmental programs to change the food environment inside schools are likely to also have an effect on the outside school environment (14). Any governmental attempt to change the external food environment is likely to meet with some resistance, both from shop owners and the general public. It is therefore important that government, when implementing these measures, informs the public behind the reason of the measure.
This research provides policy makers in Flanders with important data about the food environment near schools, which can be used as a foundation to create policies aimed at improving the food environment. Recommendations for further research include measuring and modelling additional health indicators such as the children’s cholesterol level, triglycerides, blood pressure, etc.. Another suggestion for future studies is to explore the link between the food environment outside schools and the food environment inside schools and the combined impact they have on the children’s weight status.
This study has some key strengths and limitations. This is the first comprehensive survey on retail food environments around schools in Flanders, using the largest assembled food outlet list. The locatus data has previously been found accurate in a Dutch validation study (37). In addition, measured weight and height data from a large sample of children and adolescents in Flanders was used. It is important to note that these data were anonymized, aggregated an stratified by sex and age group on the school level by the Flemish government agency ‘Agentschap Zorg en Gezondheid’. Due to privacy reasons, data on BMI and weight status of individual children were not available for research. Hence, the nature of the data did not allow for within-school cluster analysis using the individual’s children BMI, neither did it allow for longitudinal statistical analysis that would account for repeated measurements of adiposity on the same children. Although 500- and 1000 m are common walking distances, the definition of neighborhoods in spatial studies, such as in this study, is quite arbitrary. The study setup did not allow to map individual children’s journeys from home to school and back through the food environment, neither did it account for other individual changes in risk factors for obesity such as exercise, sleep and stress.