Promoting the implementation process of Power Food (‘Krachtvoer’), an educational program on healthy nutrition for prevocational secondary schools

The importance of actively promoting the implementation process of health promotion interventions has long been widely recognized [1]. Effective interventions can only have the intended impact in the target population if they are sufficiently and appropriately implemented by intermediate users in practice [2‐4]. Similar to the development of interventions, promotion of the implementation process of interventions requires a planned approach. Several phases can be distinguished in this implementation process, namely promotion of the decision to adopt the intervention, actual implementation or use, sustainability, scaling up (to a larger group of users), and de-implementation (where the intervention is ineffective) [5‐9]. The literature has identified many types of strategies that can often be combined to achieve the implementation goals of the different implementation phases, for example, financial strategies (such as subsidy for use), education (training of users), cooperation (a consortium of stakeholders), evaluation and monitoring (monitoring of use), or participation (close involvement of the target group) [10, 11]. Strategies are selected based on identified modifiable and important determinants of the implementation process in the specific implementation context. These may include many different and interacting determinants that may be related to characteristics of the intervention (e.g., too complex to use), the intermediate user (low self-efficacy towards use), the organization of the intermediate user (inadequate facilitation of the intermediate user), and the socio-political context (school closure during the corona pandemic) [12, 13].

While descriptions of the process of intervention development are widely available in the literature, this is less the case for the process of promoting implementation. After a brief explanation of the Power Food (Dutch: Krachtvoer) program, the purpose of this article is to describe how the implementation process of this program has been and is being promoted and reflect on the key perceived success factors and challenges of our approach. Input for the reflection are available visitor data from the program website and discussions during various regular project meetings during the process.

Krachtvoer is a Dutch classroom educational program taught by teachers to first and second graders of prevocational secondary schools (aged 12 to 14 years). The goal is to help students make lasting healthy lifestyle choices. The main themes are fruit, drinking, and healthy snacks. The program consists of 13 modules of 30–45 minutes each, part of which can be chosen “to taste” by the teacher, thereby responding to the needs of a class. The minimal version comprises eight lessons over a period of several weeks. Krachtvoer was developed systematically based on available theoretical and empirical knowledge and has a phased approach. Successive modules offer the steps necessary to achieve lasting behavioral change: from attention and enthusiasm for the topic of healthy eating and being aware of one’s own food choices, through identifying and improving the behavioral determinants that may be a barrier to change for the target group itself, to formulating personal goals, and to finally making, regularly evaluating, and adjusting action plans.

In Krachtvoer, students are actively engaged in their own nutrition. This is reflected in the many active and varied learning methods, such as worksheet assignments, photo assignments, environmental scans, food preparation, tasting, quizzes, and interactive games. Krachtvoer can be used by schools to start, intensify, or broaden the Healthy School Approach and obtain the nutrition theme certificate of the Dutch Healthy School Program (Gezondeschool.nl).

Krachtvoer was launched in 2002. In two projects granted by the Netherlands Organization for Health Research and Development (ZonMw) (1998–2002 and 2006–2010), of which Maastricht University in Maastricht, the Netherlands was the project leader, first and second (hard copy) versions of Krachtvoer were developed and implemented in schools, and evaluation and implementation studies were conducted [14, 15]. This resulted in a “Good evidence of effectiveness” recognition by the Dutch National Institute for Public Health and the Environment (RIVM) in 2015. From the start, cooperation with various research and practice partners has been established. Around 2015, a cooperation with educational organization Yuverta (then CITAVERDE), and thus with the educational domain, was also established. Starting in 2017, the two organizations worked towards developing an updated version of Krachtvoer by using an intensive co-creation approach with users and an intersectoral network of national partners [16].

Krachtvoer has been available on the Krachtvoer.nu website since the summer of 2019 and was rerecognized by the National Institute for Public Health and the Environment by the end of 2021. The website acts as a broad support program for use. After signing up on the website once, teachers have access to the teaching materials, including teacher manuals, lesson plans, worksheets, and ready-to-use interactive whiteboard (digibord) presentations with short videos, interactive quizzes, and instructions for assignments. Teachers can find step-by-step support on the website to get started with Krachtvoer, and each module includes a range of support options, such as substantive background information on for example types of fats, or tips for interacting with students. In addition, possibilities for program expansions are offered, for example with regard to other lifestyle behaviors.

The target group of users of Krachtvoer are teachers at over 450 school institutions, where over 300,000 prevocational first- and second-grade students are educated (https://​ocwincijfers.​nl).

Tab. 1 summarizes the key determinants identified in the implementation context of Krachtvoer and the implementation strategies that respond to barriers of implementation. The determinants were identified and selected based on previous research on the implementation of Krachtvoer [17], information gathered from stakeholders during the co-creation approach [16], and the literature (e.g. [3, 6, 12, 13, 18‐24]).

During the 2019–2020 school year, the first year the website was available, the website had 1762 unique visitors and 2849 visits, while there were 3227 unique visitors and 4848 visits in 2020–2021 and 2546 unique visitors and 3797 visits in 2021–2022. The bounce rate, which is the percentage of visits aborted within a second, was around 36% in the first two years and around 33% in the third year. In all school years, the percentage of visitors who revisited the website hovered around 17%. About two-thirds of visitors visited more than one page during a visit, an average of 4 to 5. The pages of the first three modules were visited five times more often than those of the other modules. The website was visited from all over the Netherlands but mostly from Limburg and the Randstad. Each year, the website was, relatively speaking, most frequently visited in December and March. During (summer) holidays, there was a minimal number of visitors.

By July 1, 2022, 631 people were signed up as user, compared with 418 in July 2021 and 243 in July 2020. Over all years, the most sign-ups, relatively speaking, were seen in the spring. The 631 signed-up users represent 204 schools, 137 of which offer prevocational education. In three-quarters of the cases, there is one signed-up user per school. The remaining signed-up users who are employed by an educational institution work, for example, at an elementary school, a secondary school where prevocational education is not offered, or a vocational school. Other signed-up users are working, for example, as dieticians or coaches or are employed by a Public Health Service. During the third school year, about two-thirds (n = 420) of all signed-up users logged in, of whom 36% (n = 230) logged in at least twice. Of this latter group, 89% are employed by an educational institution. When signing up, enrollees most often indicated they intended to use Krachtvoer for prevocational level 1 students (the most basic level) (n = 392), followed by level 2 students (n = 315), level 4 students (n = 268), and finally level 3 students (n = 206). Intentional use among second graders (n = 458) was mentioned slightly more often than use among first graders (n = 391). Intentional use by non-intended education and grade levels was also reported (n = 27), such as use in senior general secondary education or upper elementary school.

The purpose of this article was to describe the planned process of promoting the implementation of Krachtvoer and, based in part on visitor data from the Krachtvoer website, to reflect on the approach.

To promote the implementation of Krachtvoer, a combination of almost all types of implementation strategies mentioned in the literature has been employed [11]. A combination of implementation strategies that span the different implementation phases and drive support, education/training, cooperation, finance, participation, monitoring/evaluation, infrastructure, and adaptations to make the program appropriate to the implementation context is also considered most effective in the literature [10, 29, 30]. The planned approach helped us arrive at this complete set of implementation strategies by not overlooking key phases, determinants, or possible types of implementation strategies.

The basic idea of the planned approach is that each strategy within the complex process of promoting implementation serves its own purpose and thereby adds value. Nevertheless, especially the project team’s leading role characterized by the cooperation between the education/practice domain and health/research domain, the co-creation with users, and the intersectoral cooperation with national partners are perceived by us as essential. This allows for a continuous fit of both the intervention and the package of implementation strategies with the implementation context.

Major challenges lie in monitoring and evaluation research. The importance of these is evident, but due to lack of manpower and time, the (continuous) implementation of these strategies is still far from optimal. The visitor data we can currently report give some indication of the interest in Krachtvoer but say little about the adoption and the actual use and sustainability of Krachtvoer, both in terms of quantity and quality, and the contribution of the implementation strategies deployed to furthering the various implementation goals. This has also resulted in little feedback from implementation practices since 2019 for improvements to the intervention and implementation strategies. In addition, the visitor data are difficult to interpret with regard to the evaluation of implementation strategies because of the corona pandemic. Nevertheless, some developments in the visitor data are positive, namely the continuous growth in enrolled users and the lower bounce rate in the third school year. After three years, the signed-in users represent 16.5% of all secondary schools in the Netherlands where Krachtvoer can be offered, whereas before the corona pandemic, 10% in two years was the target. The user data also provide indications that Krachtvoer may be used in target groups other than the intended target group. Without better monitoring and evaluation, it is not possible to say whether this is undesirable and strategies should be employed for de-implementation.

The lack of structural financial support for sustaining and scaling up the intervention and the structural implementation of the implementation strategies is perceived as the main challenge and even frustration. This now always depends on short-term grants to deploy manpower and the “voluntary” commitment of many stakeholders. We are fortunate that stakeholders, in their time between subsidized project periods, want to continue their commitment to quality sustainability and improvement and dissemination actions (guided by monitoring and evaluation), in addition to their regular work. However, the downside risk is high and keeping the returns of previous temporary subsidies accessible to practitioners is thus not evident. A national (funding) policy in the Netherlands to support the sustainability of proven effective and well-implementable health promotion interventions is sorely missed.

We realize that the above identification of the success factors and challenges of our approach is based on our own experiences and not on systematically collected and analyzed data. Nevertheless, we hope that our description of the process of promoting the implementation process and our reflection on it will be of value to others trying to promote the implementation of interventions in the Dutch setting and will also provide input to policy makers on the barriers encountered in practice.