Context matters-the phased development of an adaptable food literacy intervention: Up for Cooking.

Adapting interventions to the context increases the impact and sustainability of interventions. Literature acknowledges the need to adapt existing interventions and that these adaptations should be clearly reported. However, little is known about how to incorporate adaptation from the beginning. This paper argues that interventions should be developed and adaptations should be made using an ongoing non-linear approach. An action-oriented research approach with feedback loops is proposed. We illustrate this with the development of a food literacy intervention 'Up for Cooking' (Dutch: Zin in Koken) and present lessons learned in developing, implementing and studying such adaptable interventions. Interventions should clearly define and differentiate the intervention function and form. Implementers, in turn, should be encouraged to tailor interventions within a form that fits with a specific context. Sufficient time, continuous adaptation based on co-creation, feedback loops and interdisciplinary collaboration are important prerequisites for the development of adaptable interventions.

Fidelity, adaptation and integration of whole-school health promotion within Dutch schools: a cross-sectional survey study.

Implementing comprehensive health promotion programs in the school setting can be challenging, as schools can be considered complex adaptive systems. As a first step towards understanding what works in improving implementation for which schools and under which conditions, this study aimed to examine the degree of implementation of health promoting school (HPS) programs, in terms of five dimensions of fidelity (adherence, dose, participant responsiveness, quality of delivery and program differentiation), and the dimensions of adaptation and integration. The HPS Implementation Questionnaire was distributed among ±â€…2400 primary, secondary, secondary vocational and special needs schools in the Netherlands. Employees of 535 schools (22.3%) filled out the questionnaire. Data were analysed by descriptive statistics and ANOVA tests. The average degree of implementation was 2.55 (SD = 0.58, range = 0.68-3.90; scaled 0-4). The lowest scores were achieved for participant responsiveness and adherence, and the highest for integration and adaptation. Schools that identified as HPS reported significantly higher overall degree of implementation, adherence, dose, participant responsiveness, program differentiation and adaptation than schools that didn't. Primary schools achieved a significantly higher degree of implementation, dose, participant responsiveness, quality of delivery and integration than other school types. In conclusion, many schools work on student health and well-being to some extent, but the vast majority have much room for improvement. Higher implementation scores for schools that identified as HPS underline the value of HPS programs. A broader perspective on health and more insight into conditions for effectiveness and implementation in secondary and secondary vocational schools are needed.

Implementing multiple intervention strategies in Dutch public health-related policy networks.

Improving public health requires multiple intervention strategies. Implementing such an intervention mix is supposed to require a multisectoral policy network. As evidence to support this assumption is scarce, we examined under which conditions public health-related policy networks were able to implement an intervention mix. Data were collected (2009-14) from 29 Dutch public health policy networks. Surveys were used to identify the number of policy sectors, participation of actors, level of trust, networking by the project leader, and intervention strategies implemented. Conditions sufficient for an intervention mix (≥3 of 4 non-educational strategies present) were determined in a fuzzy-set qualitative comparative analysis. A multisectoral policy network (≥7 of 14 sectors present) was neither a necessary nor a sufficient condition. In multisectoral networks, additionally required was either the active participation of network actors (≥50% actively involved) or active networking by the project leader (≥monthly contacts with network actors). In policy networks that included few sectors, a high level of trust (positive perceptions of each other's intentions) was needed-in the absence though of any of the other conditions. If the network actors were also actively involved, an extra requirement was active networking by the project leader. We conclude that the multisectoral composition of policy networks can contribute to the implementation of a variety of intervention strategies, but not without additional efforts. However, policy networks that include only few sectors are also able to implement an intervention mix. Here, trust seems to be the most important condition.

Explaining use of food parenting practices: the importance of predisposing factors and parental cognitions.

OBJECTIVE: The high energy intake from energy-dense foods among children in developed countries is undesirable. Improving food parenting practices has the potential to lower snack intakes among children. To inform the development of interventions, we aimed to predict food parenting practice patterns around snacking (i.e. 'high covert control and rewarding', 'low covert control and non-rewarding', 'high involvement and supportive' and 'low involvement and indulgent'). DESIGN: A cross-sectional survey was conducted. To predict the patterns of food parenting practices, multinomial logistic regression analyses were run with 888 parents. Predictors included predisposing factors (i.e. parents' and children's demographics and BMI, parents' personality, general parenting, and parenting practices used by their own parents) and parents' cognitions (i.e. perceived behaviour of other parents, subjective norms, attitudes, self-efficacy and outcome expectations). SETTING: The Netherlands (October-November 2014). SUBJECTS: Dutch parents of children aged 4-12 years old. RESULTS: After backward elimination, nineteen factors had a statistically significant contribution to the model (Nagelkerke R 2=0·63). Overall, self-efficacy and outcome expectations were among the strongest explanatory factors. Considering the predisposing factors only, the general parenting factor nurturance most strongly predicted the food parenting clusters. Nurturance particularly distinguished highly involved parents from parents employing a pattern of low involvement. CONCLUSIONS: Parental cognitions and nurturance are important factors to explain the use of food parenting practices around snacking. The results suggest that intervention developers should attempt to increase self-efficacy and educate parents about what constitute effective and ineffective parenting practices. Promoting nurturance might be a prerequisite to achieve prolonged change.

Intake of energy-dense snack foods and drinks among Dutch children aged 7-12 years: how many, how much, when, where and which?

OBJECTIVE: To describe the energy-dense snack food (EDSF) and energy-dense drink (EDD) consumption of children in the Netherlands and investigate subgroup differences. The amounts consumed, eating occasions, places of consumption and consumed types are reported. DESIGN: Twenty-four hour dietary recall data were used to describe the EDSF and EDD consumption. Subgroup differences concerning these intakes were identified with ANCOVA. SETTING: Dutch National Food Consumption Survey 2007-2010. SUBJECTS: Children (n 860) aged 7-12 years. RESULTS: The mean number of EDSF events was 3·3 (sd 1·6) per day, yielding 1569·7 (sd 928·7) kJ. Average EDD consumption was 594·2 (sd 342·3) ml/d, yielding 737·2 (sd 495·9) kJ. Over 90 % of the children consumed more energy from non-core foods per day than recommended. Differences in EDSF and EDD consumption were found between several subgroups. Most importantly, we found higher intakes among older children and children with low educated mothers. Almost half of the EDSF events took place in the afternoon and at home. Cookies and sweets were consumed during half of the EDSF events. Almost one-third of the EDD were consumed in the afternoon. The majority of these drinks were consumed at home and most were soft drinks. CONCLUSIONS: The results demonstrate that snack food and drink consumption is highly prevalent among Dutch children. Health promotion efforts addressing these behaviours are warranted and the present study could accelerate these initiatives. Focusing on children with low educated parents and on snacking at home after school offers the greatest potential to reduce snack food and drink intakes.

The assessment of ongoing community-based interventions to prevent obesity: lessons learned.

BACKGROUND: The assessment of real-life, community-based interventions to tackle obesity is an important step in the development of effective policies. Especially multi-level interventions have a high likely effectiveness and potential reach in counteracting the obesity epidemic. Although much can be learned from these initiatives, performing an evaluation of such interventions is challenging. The aim of the current article is to provide a descriptive overview of the data collection process and general results of an assessment of ongoing multi-level obesity prevention community interventions for adults in Europe, and the lessons learned from this effort. METHODS: The data collection was divided into two main phases: a) finding the ongoing obesity prevention interventions by contacting key informants in each of the European Union countries and the European Economic Area, and searching existing databases; and b) collecting detailed information (including the reach, effectiveness, adoption, implementation and maintenance (RE-AIM)) of the selected interventions using questionnaires for informants in each of the interventions. RESULTS: A total of 78 interventions from 24 European countries were included in the final sample. The number of identified interventions varied greatly per country. The interventions covered various implementation levels (national, regional or local) and determinants (physical, sociocultural, economic, political), mostly addressing both nutrition and physical activity behaviours. CONCLUSIONS: We found that many multi-level obesity prevention interventions among adults are currently active in Europe, although we found relatively few in Southern and Eastern Europe. Identifying interventions and obtaining detailed information proved to be a difficult, time consuming and painstaking process. We discuss some of the reasons why this might be the case and present recommendations based on our experiences. We suggest that future research uses a step-wise approach, keeping participant burden to a minimum. The use of personalised and tailored strategies is recommended, led by researchers who exercise flexibility, tact and patience during the data collection process.

Associations between general parenting, restrictive snacking rules, and adolescent's snack intake. The roles of fathers and mothers and interparental congruence.

INTRODUCTION: Little research has been done on the role of fathers and parenting congruence between mothers and fathers. This study aimed to clarify the roles of general parenting and restrictive snacking rules set by fathers and mothers, and to explore parenting congruence in explaining adolescents' snack intake. METHODS: Adolescents aged 11 to 15 completed a questionnaire assessing their perception of general parenting constructs (i.e. nurturance, structure, behavioral control, coercive control, and overprotection), restrictive snacking rules set by their fathers and mothers, and their own energy-dense snack intakes between meals. RESULTS: Scores for mothers were significantly higher on all constructs than for fathers, except for coercive control. Generally, higher scores on general parenting constructs were associated with higher scores on restrictive snacking rules (most of the associations being significant). Most general parenting constructs were unrelated to the respondents' number of snacks consumed. The use of restrictive snacking rules by both fathers and mothers was significantly and negatively related to respondents' snack intake. Moderation analyses indicated that high levels of incongruence between parents attenuated the favorable impact of fathers' rules and nurturance on their children's snacking, but interactions of congruence with three other paternal scales and all maternal scales were absent. DISCUSSION: Our findings indicate that both paternal and maternal general parenting and restrictive snacking rules play important roles in adolescents' snacking, and that high parental incongruence regarding restrictive snacking rules and nurturance could be undesirable.

Emotional and instrumental feeding practices of Dutch mothers regarding foods eaten between main meals.

BACKGROUND: To assess how much of a public health problem emotional and instrumental feeding practices are, we explored the use of these feeding practices in a sample of Dutch mothers regarding their child's food intake between main meals. METHODS: A cross-sectional questionnaire study was conducted among 359 mothers of primary school children aged 4-12 years. The questionnaires were completed online at home. RESULTS: Of the mothers, 29.5% reported using foods to reward, 18.1% to punish and 18.9% to comfort their child. Mothers most frequently offered energy-dense and nutrient-poor products such as candy in the context of emotional and instrumental feeding practices. The use of these practices was associated with a lower age of both mother and child and a higher educational level of the mother. Mothers living in neighborhoods with intermediate socioeconomic position used the practices less often than mothers from low and high socioeconomic position neighborhoods. CONCLUSIONS: Our results show that mothers in our sample mainly used unhealthy products in the context of instrumental and emotional feeding practices. Research into the association between these practices and children's dietary intake is warranted, since the use of unhealthy products in the context of these practices may not necessarily lead to an increased consumption of these products. Findings regarding the frequency of use of these practices among specific subgroups can be used to carefully determine the target population for interventions and tailor the content of interventions to specific target group characteristics. Besides examining associations between personal and family characteristics and the use of emotional and instrumental feeding practices, attempts should be made to understand parents' reasons for using them.

Examining the relationship between completeness of teachers' implementation of the Krachtvoer healthy diet programme and changes in students' dietary intakes.

OBJECTIVE: The goal of the current study was to examine if the completeness of programme implementation and the completeness of implementation of specific programme elements of the Dutch school-based healthy diet promotion programme Krachtvoer are related to short- and longer-term changes in students' fruit, sweets and breakfast intakes. DESIGN: Data on students' dietary intakes were collected 1­4 weeks and 6 months after programme implementation. Teachers filled in a logbook on programme implementation after each lesson. The relationships between changes in students' dietary intakes and completeness of implementation of the programme and of specific programme elements were tested using mixed linear regression analyses. SETTING: Thirteen Dutch prevocational schools. SUBJECTS: Eight hundred and seventy-six of the 1117 participating students and eighteen of the twenty-two participating teachers. RESULTS: Completeness of programme implementation was positively related to an increase in fruit consumption in the short term. Completeness of implementation of food exposure activities and a practical lesson on advertisements were related to an increase in fruit consumption in the short as well as the longer term. No such relationships were found for sweets and breakfast consumption. CONCLUSIONS: Our results indicate that efforts should be made to help teachers implement the programme as fully as possible.

Psychosocial determinants of fruit and vegetable consumption among students in a New Zealand university. Results of focus group interviews.

The '5+ a day' fruit and vegetable servings recommendation was introduced in New Zealand in 1994, but consumption has remained low in young adults ever since. This study aimed to identify psychosocial determinants of fruit and vegetable consumption among New Zealand university students approximately a decade after the guidelines' introduction. Twenty-nine students, aged 18-24 years, took part in focus group interviews. Important determinants included taste and health awareness/knowledge. Flatmates and partners had the greatest social influence. Cost and availability were major barriers to consumption. To improve consumption participants suggested: cooking sessions providing quick/easy recipes; more-varied nutritional information; 'made-to-measure' interventions; increasing awareness of cheap sources of fruit/vegetables; and increasing campus availability of fruit. Determinants including a negative attitude, a lack of self-efficacy and an unawareness of dietary guidelines/health consequences should be considered when developing interventions for this group, whilst a variety of different delivery channels should be used. Participants in the study were not representative of all university students, who generally have a different lifestyle to other young adults and specific determinants for fruit/vegetable consumption. Consequently, additional research is required among other young adults and university students with lower fruit and vegetable intake, so that promotional strategies can be specifically targeted.

Measuring Implementation of Health Promoting School (HPS) Programs: Development and Psychometric Evaluation of the HPS Implementation Questionnaire.

BACKGROUND: Implementation of Health Promoting School (HPS) programs can be challenging due to the dynamic school context. Navigating between program fidelity and adaptation, as well as integrating the program, is essential for successful implementation, and consequently, for program effects. As part of an evaluation study in the Netherlands, this study aimed to develop a measurement instrument that differentiates schools according to fidelity, adaptation, and integration of HPS implementation. METHODS: This study presents the development and psychometric evaluation of the 28-item HPS Implementation Questionnaire, covering 7 dimensions: adherence, dose, participant responsiveness, quality of delivery, program differentiation, adaptation, and integration. The questionnaire, to be filled out by school employees, was developed for primary, secondary, secondary vocational, and special needs education, in close collaboration with experts (n = 54) in school health promotion. RESULTS: Semi-structured interviews aimed at dimension clarification resulted in a list of 58 items. Items were revised, combined, and/or removed based on quantitative and qualitative feedback by the evaluation study's Community of Practice, 2-round expert consultation, and pre-tests. Psychometric evaluation (n = 535 schools), consisting of calculating Cronbach's α and confirmatory factor analysis (CFA), confirmed internal consistency (α > .72) and the 7-dimension framework. CONCLUSION: The brief yet comprehensive HPS Implementation Questionnaire offers possibilities for research into HPS implementation in various educational sectors and contexts, as well as self-monitoring by individual schools. This study provides first evidence for internal consistency and validity of the questionnaire.

Healthier food choices as a result of the revised healthy diet programme Krachtvoer for students of prevocational schools.

BACKGROUND: Krachtvoer is a Dutch healthy diet programme for prevocational schools, developed in 2001 and revised for a broader target group in 2007, based on the findings of an evaluation of the first version. The goal of this study was to report on the short- and longer-term total and subgroup effects of the revised programme on students' fruit, fruit juice, breakfast, and snack consumption. METHODS: Schools were randomized to the experimental condition, teaching the Krachtvoer programme, or to the control condition teaching the regular nutrition lessons. Self-reported consumption of fruit, fruit juice, breakfast and snacks was measured at baseline directly before programme implementation, one to four weeks after finishing programme implementation, and after six months. Mixed linear and logistic regression analyses were conducted. RESULTS: In total 1117 students of 13 experimental schools and 758 students of 11 control schools participated in the study. Short- and longer-term favourable intervention effects were found on fruit consumption (mean difference between experimental and control group 0.15 servings at both posttests). Regarding fruit juice consumption, only short-term favourable effects were revealed (mean difference between experimental and control group 0.05 glasses). Intervention effects on breakfast intakes were limited. No changes in snack frequency were reported, but students made healthier snack choices as a result of the programme. Some favourable as well as unfavourable effects occurred in subgroups of students. CONCLUSIONS: The effects on fruit consumption and snack choices justify the current nationwide dissemination of the programme. Achieving changes in breakfast consumption may, however, require other strategies.

Sustainable prevention of obesity through integrated strategies: The SPOTLIGHT project's conceptual framework and design.

BACKGROUND: The prevalence of overweight and obesity in Europe is high. It is a major cause of the overall rates of many of the main chronic (or non communicable) diseases in this region and is characterized by an unequal socio-economic distribution within the population. Obesity is largely determined by modifiable lifestyle behaviours such as low physical activity levels, sedentary behaviour and consumption of energy dense diets. It is increasingly being recognised that effective responses must go beyond interventions that only focus on a specific individual, social or environmental level and instead embrace system-based multi-level intervention approaches that address both the individual and environment. The EU-funded project "sustainable prevention of obesity through integrated strategies" (SPOTLIGHT) aims to increase and combine knowledge on the wide range of determinants of obesity in a systematic way, and to identify multi-level intervention approaches that are strong in terms of Reach, Efficacy, Adoption, Implementation and Maintenance (RE-AIM). METHODS/DESIGN: SPOTLIGHT comprises a series of systematic reviews on: individual-level predictors of success in behaviour change obesity interventions; social and physical environmental determinants of obesity; and on the RE-AIM of multi-level interventions. An interactive web-atlas of currently running multi-level interventions will be developed, and enhancing and impeding factors for implementation will be described. At the neighbourhood level, these elements will inform the development of methods to assess obesogenicity of diverse environments, using remote imaging techniques linked to geographic information systems. The validity of these methods will be evaluated using data from surveys of health and lifestyles of adults residing in the neighbourhoods surveyed. At both the micro- and macro-levels (national and international) the different physical, economical, political and socio-cultural elements will be assessed. DISCUSSION: SPOTLIGHT offers the potential to develop approaches that combine an understanding of the obesogenicity of environments in Europe, and thus how they can be improved, with an appreciation of the individual factors that explain why people respond differently to such environments. Its findings will inform governmental authorities and professionals, academics, NGOs and private sector stakeholders engaged in the development and implementation of policies to tackle the obesity epidemic in Europe.

Supporting schools during the implementation of the health-promoting school approach: The roles of a healthy school advisor.

Introduction: The health-promoting school (HPS) approach was developed by the World Health Organization to create health promotion changes in the whole school system. Implementing the approach can be challenging for schools because schools are dynamic organizations with each a unique context. Many countries worldwide have a health promotion system in place in which healthy school (HS) advisors support schools in the process of implementing the HPS approach. Even though these HS advisors can take on various roles to provide support in an adaptive and context-oriented manner, these roles have not yet been described. The current study aims to identify and describe the key roles of the HS advisor when supporting schools during the dynamic process of implementing the HPS approach. Methods: The study was part of a project in which a capacity-building module was developed for and with HS advisors in the Netherlands. In the current study, a co-creation process enabled by participatory research was used in which researchers, HS advisors, national representatives, and coordinators of the Dutch HS program participated. Co-creation processes took place between October 2020 and November 2021 and consisted of four phases: (1) a narrative review of the literature, (2) interviews, (3) focus groups, and (4) a final check. Results: Five roles were identified. The role of "navigator" as a more central one and four other roles: "linking pin," "expert in the field," "critical friend," and "ambassador of the HPS approach." The (final) description of the five roles was recognizable for the HS advisors that participated in the study, and they indicated that it provided a comprehensive overview of the work of an HS advisor in the Netherlands. Discussion: The roles can provide guidance to all Dutch HS advisors and the regional public health organizations that employ them on what is needed to provide sufficient and context-oriented support to schools. These roles can inspire and guide people from other countries to adapt the roles to their own national context.

Effects of a brief cardiovascular prevention program by a health advisor in primary care; the 'Hartslag Limburg' project, a cluster randomized trial.

OBJECTIVE: To determine in primary care patients at high risk for a cardiovascular event, the effects on biomedical risk factors for and incidence of cardiovascular events, of a brief cardiovascular prevention program executed by a health advisor. DESIGN: cluster randomized controlled trial with 1275 patients (24 general practices) in and around Maastricht, the Netherlands (1999-2004). INTERVENTION: health advisors were to complete computerized cardiovascular risk profiles, provide multi-factorial tailored health education and advice, and communicate with GP's to optimize treatment. OUTCOME: differences in changes in risk factors between baseline and follow up at 6, 18, and 36 months and incidence of cardiovascular events at 36 months. PROCESS: Because of logistic reasons risk profiles were put on paper instead of in the computerized patient files. On average patients attended 2.3 counseling sessions. Interaction with GPs was less productive than expected. OUTCOME: Effect after six months on BMI (-0.20 kg/m(2) (95% CI -0.38 to -0.01, p=0.039), Cohen's d: -0.18), and after 18 months on HDL-cholesterol (+0.05 mmol/l (95% CI +0.01 to +0.09, p=0.014), Cohen's d: 0.14). No other (subgroup) effects were found. CONCLUSION: Given the lack of clinically meaningful effects, implementation of this intervention in its present form is not justified.

Appreciation and implementation of the Krachtvoer healthy diet promotion programme for 12- to 14- year-old students of prevocational schools.

BACKGROUND: Krachtvoer is a school-based healthy diet programme, developed in 2001 and revised in 2007 to meet the needs of particular segments of the target population as well as a wider target group. The main aims of the present process evaluation of the revised programme were to examine student and teacher appreciation of the programme, completeness of and adherence to its implementation, and relations between appreciation and completeness of implementation. METHODS: Data were collected among 22 teachers and 1117 students of 13 schools, using student evaluation forms, teacher logbooks, telephone interviews, and classroom observations. RESULTS: Results indicate favourable levels of teacher and student appreciation for the programme in general and the revised elements. Girls, first-year students and students with more favourable dietary intakes particularly appreciated individual programme elements. Levels of completeness of implementation were high, but several teachers did not adhere to the intended implementation period. Some moderately strong relations were found between teacher appreciation and completeness of implementation scores. CONCLUSION: We conclude that the revisions have resulted in a programme that was appreciated well, also by the extended target group, and was implemented with a high degree of completeness. Teacher appreciation proved potentially important for completeness of implementation. We identified several aspects requiring improvement, indicating the importance of continued programme updates and repeated evaluation.

Evaluation of an adoption strategy for a healthy diet programme for lower vocational schools.

This paper describes the evaluation of an adoption strategy for the school-based healthy diet programme Krachtvoer. Health promotion (HP) professionals from five Regional Public Health Services (RPHSs) in The Netherlands were asked to recruit a total of 25 schools to adopt the Krachtvoer programme in accordance with this strategy. Afterwards, they were interviewed about their adherence to and subjective evaluation of the strategy. The adoption rate of the programme was calculated and 10 adopting and 9 rejecting teachers were interviewed about the reasons for their decision. The HP professionals' adherence to the strategy was good, as well as their appreciation and the perceived feasibility of the strategy. The person-to-person approach that characterized this strategy was considered important. The strategy led to an adoption rate of 53.2%. On average, adopters mentioned 4.4 reasons and rejecters mentioned 5.4 reasons for their decision. Most reasons were school related and programme related and in case of the adopters also teacher related. The diversity of reasons revealed the complexity of teachers' decision making. Although there is some room for improvement of the adoption strategy and the programme itself, especially socio-political conditions in schools and in RPHSs need change for a further increase in programme adoption.

Exploring the conceptualization of program theories in Dutch community programs: a multiple case study.

Our objective was to evaluate whether the limited effectiveness of most community programs intended to prevent disease and promote health should be attributed to the quality of the conceptualization of their program theories. In a retrospective multiple case study we assessed the program theories of 16 community programs (cases) in the Netherlands (1990-2004). Methods were a document analysis, supplemented with member checks (insider information from representatives). We developed a community approach reference framework to guide us in reconstructing and evaluating the program theories. On the whole, programs did not clearly spell out the process theories (enabling the implementation of effective interventions), the program components (interventions) and/or the impact theories (describing pathways from interventions to ultimate effects). Program theories usually turned out to be neither specific nor entirely plausible (complete and valid). The limited effectiveness of most community programs should most probably be attributed to the limited conceptualization of program theories to begin with. Such a failure generally also precludes a thorough examination of the effectiveness of the community approach as such.

The Effects of the Healthy Primary School of the Future on Children's Fruit and Vegetable Preferences, Familiarity and Intake.

Mere exposure is an often-described strategy to increase children's food familiarity, preferences, and intake. Research investigating this method in less controlled settings is scarce. This study investigates the effects of repeated fruit and vegetable (FV) exposure through the Healthy Primary School of the Future (HPSF) on children's FV familiarity, preferences, and intake. The study had a longitudinal quasi-experimental design comparing two full HPSFs (focus: nutrition and physical activity) with two partial HPSFs (focus: physical activity) in the Netherlands. Annual measurements (child-reported questionnaires) were conducted during 2015-2019 in 833 7-12-year-old children. The study was registered on ClinicalTrials.gov (NCT02800616). After correction for baseline, full HPSFs had, on average, a lower number of unfamiliar vegetable items after one (effect size (ES) = -0.28) and three years (ES = -0.35) and a higher number of disliked vegetable items after one year (ES = 0.24) than partial HPSFs. Unfavorable intervention effects were observed for fruit intake after one (odds ratio (OR) = 0.609) and four years (OR = 0.451). Repeated FV exposure had limited effects on children's FV familiarity, preferences, and intake, likely due to insufficient taste exposure. Considering the widespread implementation of school-based mere exposure efforts, it is highly relevant to further investigate under which circumstances mere exposure effectively contributes to improvements in (determinants of) FV intake.

Co-Creation Approach with Action-Oriented Research Methods to Strengthen "Krachtvoer"; A School-Based Programme to Enhance Healthy Nutrition in Adolescents.

In recent years, the nutritional pattern of the Dutch adolescent has cautiously improved. However, progress can be gained if more Dutch adolescents adhere to the nutritional guidelines. School-based initiatives offer opportunities to deal with the unhealthy eating behaviours of adolescents via nutrition educational interventions. In designing and/or re-designing school-based interventions, it is important to enhance optimal context-oriented implementation adaptation by involving the complex adaptive school system. This paper elaborates on the way of dealing with the dynamic implementation context of the educational programme "Krachtvoer" (ENG: "Power food") for prevocational schools, how the programme can be adapted to each unique implementation context, and how the programme can be progressively kept up to date. Following a co-creation-guided approach with various intersectoral stakeholders within and outside the school setting, action-oriented mixed research methods (i.e., observations, semi-structured interviews, focus group interviews, programme usage monitoring, and questionnaires) constantly provide input to develop the programme and its implementation strategy via continuous micro-process cycles. Successful co-creation of school-based health promotion seems to be dependent on proper intersectoral cooperation between research and practice communities, a national partner network that can provide project-relevant insights and establish capacity building aimed at improving contextual fit, and a time-investment balance in and between sectors.