Page 95 - ON THE WAY TO HEALTHIER SCHOOL CANTEENS - Irma Evenhuis

INTRODUCTION
School is a useful setting in which to stimulate healthy dietary behaviour in adolescents [197, 198]. National or regional policy focused on provision of healthier foods and drinks in canteens and vending machines in schools seems to encourage adolescents to eat more healthily during school time [27, 38, 199]. In the Netherlands, students bring most foods and drinks from home, as schools do not provide meals in the absence of a national/ regional school meal plan. Most schools have a canteen and/or vending machines, where students buy substitutional snacks or drinks. Due to the absence of national guidance and international consensus on how to define a ”healthier canteen”, the Netherlands Nutrition Centre developed the Dutch “Guidelines for Healthier Canteens” [78]. These guidelines were developed in collaboration with future users and experts in the field of nutrition and health behaviour and are based on Dutch nutritional guidelines, experiences with the Dutch Healthy School Canteen Programme, and research on influencing food choices and nudging [25, 73, 79]. These canteen guidelines aim to assist stakeholders in school, sports, and worksite canteens to create a healthier canteen. According to these guidelines, a healthier canteen increases the offer (availability) and presentation/promotion (accessibility) of healthier products, by using three incremental levels: bronze, silver, and gold [78].
As stakeholders need support to increase compliance with guidelines [39, 52], an imple- mentation plan based on their perceived factors that hamper or enable implementation
is needed [63]. The implementation plan to support implementation of the Guidelines
for Healthier Canteens was developed in collaboration with stakeholders and based on 6 behaviour change models and implementation strategies [62, 64, 65, 130]. Stakeholders
gave their input about their experienced or expected barriers or facilitators regarding implementation of school canteen guidelines. The implementation plan aims to address these factors. To evaluate the impact of the implementation plan, changes in these factors should be studied [51]. Such involved barriers or facilitators can arise within the person, as motivation, attitude, and skills or can arise from the environmental context of school or the guidelines, as support from the organisation and the possibility to adjust the guidelines to your own context [99]. To date, the impact of supportive implementation of school based policies on changes in individual or environmental factors is seldom assessed [51].
Studies have shown that implementing school based interventions as intended (fidelity) is a challenge, and that better implementation results in greater effect [120, 200]. Insight into the quality of implementation through process evaluation concepts such as fidelity and dose received (completeness) is therefore useful [101, 201], as proper evaluation can reveal why an intervention is (not) effective and how it can be optimized [122]. This study evaluated in Dutch secondary school canteens: (a) the effect of the combination of implementation tools on individual and environmental factors affecting implementation as perceived by stakeholders; and (b) the quality of implementation of each tool.
93