Background
Although average life expectancy has increased, in general people have more unhealthy life-years, particularly due to an increase in premature non-communicable diseases including cardiovascular diseases, diabetes and cancer [
1‐
3]. An unhealthy diet is one of the drivers of this trend [
4]. Dietary behaviour has shown an unfavourable change, influenced by factors on the individual level like behavioural determinants and demographic factors as well as factors within the food environment [
5,
6]. Public food settings have tended to increase the offer (availability), placement and promotion (accessibility) of unhealthy calorie-dense food and beverages [
7]. These changes encourage people to consume these foods and drinks more frequently [
8‐
11]. It is important to change the unhealthy food environment into one that helps individuals to make healthier food choices [
12].
In recent years, efforts have been made to create healthier food environments. Attention increased towards school food policy formulation, research on food environment measurements, and environmental interventions in settings as home, school and worksite [
13‐
15]. Increasing the availability and/or accessibility of healthier products has proven to be effective in stimulating healthier food choices (e.g. by placing more fruit/vegetables on display, advertisement for vegetables, or reducing the number of less healthy products at the point of purchases) [
12,
16‐
20]. Altering the environment to make the healthier option the easier, default option, without restricting the consumer’s freedom of choice, is also known as ‘nudging’ [
21]. Nudges are cheap to perform and require minimal effort. Examples of effective nudging strategies are: to offer a variety of healthier products instead of just one (e.g. different types of fruits), to position healthier products more attractively along the shopping route, and to increase the convenience of healthier products (e.g. sliced fruit instead of a single piece) [
22,
23]. Especially in public settings, like school/sports canteens and worksite cafeterias, where people spend much time and may consume a significant amount of their daily caloric intake, nudging has received consumers’ approval and has the potential to positively affect customers’ dietary behaviour [
11,
24,
25]. Moreover, visitors address the need for a larger range of healthy products [
26] and schools, sports associations and companies have become increasingly interested in offering a healthier canteen by making use of nudges [
27,
28].
The Dutch Ministry of Health, Welfare and Sport has set a policy target to increase the number of schools with a healthier canteen [
29,
30]. Due to the absence of international consensus on how to define a ‘healthy canteen’ [
31], the ‘Guidelines for Healthier Canteens’ were developed by the Netherlands Nutrition Centre in collaboration with experts in the field of nutrition and health behaviour. These guidelines are based on Dutch nutritional guidelines, experiences with the Dutch school canteen program, and general research on influencing food choices [
32‐
34]. The Guidelines for Healthier Canteens aim to change the food environment in school/sports canteens and worksite cafeterias by improving the availability and accessibility of healthier foods. Availability is defined as the presence of products that can be bought. Accessibility is defined as product promotion and placement [
33]. The next step is to implement these guidelines throughout the Netherlands. This requires effective infrastructure and support [
35‐
37]. Therefore, we aimed to develop a user-friendly online tool that i) helps stakeholders to understand and implement the guidelines, ii) facilitates monitoring of the canteen’s status and changes over time regarding availability and accessibility of food/beverages, and iii) that provides tailored feedback and advises how to make the canteen healthier [
13,
38]. In addition to the Netherlands, also in several other countries efforts have been made to create school food policies, such as guidelines, procedures or rules to enable a healthier school food environment [
36,
39]. However, often the actual implementation of these policies can be improved and surveillance is recommended to monitor implementation over time [
35,
36,
40]. Therefore, tools to monitor the implementation of these policies are required [
35,
39,
41,
42].
Various measurement tools are available to assess product availability/accessibility in the consumer food environment [
15,
31,
43,
44]. For example, in the United States the Nutrition Environment Measurement Survey for Stores (NEMS-S) and Restaurants (NEMS-R) are regularly used to assess the food environment and have also been tested on reliability and validity [
45,
46]. The NEMS started as a tool to assess the availability, price and quality of products in stores, and to assess the availability, facilitators, barriers, pricing and signage/promotion in restaurants. Meanwhile, a version for vending machines is also available [
47]. Unfortunately, none of the available tools were suitable to monitor Dutch canteens due to differences in nutritional guidelines and definitions of accessibility [
15,
44]. Also, Dutch canteens differ from other countries regarding the products sold because in the Netherlands, most children bring their lunch from home, so in school canteens snacks are the main purchase. Moreover, the psychometric properties of these instruments have not always been properly evaluated [
15,
44].
One of the first properties that should be assessed is the degree to which the content of the instrument is an adequate reflection of the construct to be measured (content validity) [
48]. In addition, to facilitate the use of the tool by different stakeholders and to ensure clear and usable feedback is provided by the tool, it is recommended to develop it in a close collaboration between science and practice [
49,
50]. Therefore, this paper describes the development (in close collaboration between practice and research) and assessment of the content validity and usability of the ‘Canteen Scan’.
Discussion
The present study translated the Dutch Guidelines for Healthier Canteens into an online tool called the ‘Canteen Scan’ in a 3-step iterative process. The Canteen Scan provides insight into the level of compliance with the guidelines, and offers feedback with directions for improvement. The tool was developed for and with various users, e.g. (school) canteen advisors/managers/employees and caterers, as well as involving stakeholders representing science and policy. Pilot tests revealed that stakeholders evaluated the tool positive on its usability, with positive evaluations on the concepts comprehensibility, user-friendliness, feasibility and satisfaction.
Besides the Netherlands, other countries have developed guidelines or policies and accompanying tools to stimulate healthy eating behaviour in public settings [
15,
39,
42,
44]. Unfortunately, none of the available tools were suitable to monitor Dutch school canteens due to the differences in goals, criteria and the definitions used. The Canteen Scan was specifically developed to evaluate compliance with the Dutch guidelines for canteens, according to Dutch nutritional guidelines, suitable for the products sold in Dutch school canteens and with the recommended definition (by stakeholders) of accessibility. However, the process of development and the content of the tool can be valuable to others developing a similar tool for their canteens.
To our knowledge, the Canteen Scan is the first online tool to translate policy for public food settings into a tool that combines assessments of the healthiness of products, the proportion of healthier products available in a canteen, and criteria for accessibility. In the present study, end-users evaluated the different elements of the Canteen Scan as positive on comprehensibility user-friendliness and feasibility. The combination of concepts (availability and accessibility) concurs with the recommendations of earlier tools developed to measure the consumer food environment [
15,
44]. The tool can be used by a diversity of stakeholders: school managers, canteen employees, caterers, school canteen advisors and policy makers. In accordance with recommendations, the Canteen Scan combines the functions providing insight into the current level of compliance with guidelines, monitoring changes over time, and providing tailored feedback to improve the healthiness of the canteen [
19,
35,
42,
44]. Moreover, since the adjustments with regard to accessibility/availability are immediately apparent in the result section of the tool, this may stimulate caterers and canteen managers to make changes. As the Canteen Scan is administered online, stakeholders could easily use the scan to monitor changes in healthiness over time. Another strength of the Canteen Scan is that it is linked with the Dutch database that automatically classifies commonly sold food/drink products according to the current Dutch nutritional guidelines, based on the nutritional composition of products. The fact that users themselves do not have to classify products increases the usability of the tool [
42,
69]. Moreover, this link allows to automatically include updates of the nutritional guidelines in the Canteen Scan. On national level, the (anonymized) online data might be used to monitor how many organizations implement and comply with the Guidelines for Healthier Canteens, although first more insight should be gained in the reliability and validity of the tool. The monitoring of implementation and compliance to guidelines is recommended to be able to evaluate the (un)intended effects of stated policy and to improve policy in the future [
42]. Taking all this together, the Canteen Scan appears to be a useful tool for practice.
A limitation of the tool and a possible barrier for implementation [
70] is that the use of the Canteen Scan was perceived to be time-consuming. Other comparable tools assess a more limited range of food groups, which can decrease entry time [
45,
69]. However, we chose to assess all food groups and products in order to obtain more comprehensive insight into the assortment, to be able to observe changes in the assortment, and to provide insight to users on whether replacement of certain foods actually improves their score. In addition, pilot tests showed that the investment of time was worthwhile and improvements in the database can decrease the amount of time required. Moreover, the second and subsequent uses of the scan will be less time-consuming because a previously entered scan can be copied and simply adapted.
Another limitation is that some of the items used to score accessibility are difficult to quantify and, therefore, to measure. For example, the item “healthier products are placed at an eye-catching spot” is liable to bias because “eye-catching spot” can be interpreted in different ways. Therefore, to reduce possible bias, additional explanation by text and pictures to each item might be a solution.
To increase usability in practice, collaboration of science and practice is recommended for the development of such a tool [
49,
50]. However, one of the challenges was to balance the needs and wishes from practice and the scientific evidence and to be able to align this with the technical possibilities. Consequently, certain compromises had to be made. For example, although price- and portions sizes strategies are effective [
55‐
57] they were not included as accessibility item in the tool. By practice, this was considered not yet feasible since the buying-in costs are higher for healthier options. As solution, these strategies were added as a suggestion in the general feedback. The limited number of participating stakeholders that were consulted could have influenced the results. However, we included a wide range of stakeholders (researchers, school canteen advisors, professionals representing caterers and schools) to receive a broad range of information.
The development of the Canteen Scan is a continuous process and the tool will be adapted based on input from experts and end-users. This study showed the first refinements of the measurement methods and items of the Canteen Scan based on the input of the experts and end-users. In a follow-up (quantitative) study, the criterion validity and reliability of the Canteen Scan will be investigated in a larger sample, which should lead to further improvements.
The Guidelines for Healthier Canteens are applicable in school/sports canteens and worksite cafeterias. During the expert meeting in the first step of the development of the Canteen Scan, experts advised us to focus on school canteens. Based on the noticed differences between the settings, e.g. different products, more meals on offer, and a different organisational structure (i.e. more volunteers in sports canteens). However, currently the Canteen Scan is already used in sport and worksite canteens. Based on these experiences, future refinements will be made to increase the Canteen Scan’s usability also in other settings than the school setting, such as sports canteens and worksite cafeterias.
In the future, the Canteen Scan could be combined with measurements of the broader environment, e.g. in a daily life environment (such as home, neighbourhood or shops passed on the way home). In addition, investigating the relation between the objective consumer environment (measured with the Canteen Scan) and individual purchase and eating behaviour, health outcomes and perceptions of the environment (e.g. how important price is for the consumer) might increase knowledge on the food environment and the relation with individual behaviour and health [
31,
71].