Between 1975 and 2016, the prevalence of overweight and obesity among 5-19-year-olds nearly tripled in boys and more than doubled in girls.1,2 In the World Health Organization European Region, nearly one third of children aged 6-9 years (29% of boys and 27% of girls) are living with overweight or obesity.1 Obesity can affect a child's physical and mental health, educational attainment, health in later life and quality of life.2,3 Obesity often continues into adulthood.4 Children with overweight/obesity who also have obesity in adulthood have increased risks of adverse cardiometabolic outcomes.5 Previous research shows that children with overweight or obesity who reach a healthy weight in adulthood have similar risks to those who were never obese.5 Therefore, early prevention and treatment of childhood overweight and obesity are essential for present and future health.

An “obesogenic environment” comprises interacting physical, economic and sociocultural factors that shape eating and physical activity beyond individual choice and contribute to childhood obesity.6 These conditions interact with social determinants of health, reinforcing socioeconomic inequalities in childhood obesity.7 Preventing and treating childhood obesity requires multidisciplinary action on social determinants of health.8,9 Effective prevention requires supporting families and professionals in settings that shape children's everyday lives. Strategies are needed to support the implementation and transfer of effective practices within and across countries and cultures.10,11 International collaboration and knowledge exchange can play a significant role in adapting practices across contexts.

The Joint Action for the implementation of best practices and research results on healthy lifestyles for health promotion and the prevention of non-communicable diseases and risk factors (Health4EUKids) aimed to promote healthy lifestyles and prevent childhood obesity among families with children. Two best practices were selected for implementation: Grunau Moves and Smart Family (originally Neuvokas perhe).12

The objectives of Smart Family are aligned with international policies and recommendations on health promotion and obesity prevention.1–3,8 The practice has been recognised as an EU Best Practice13 and as an effective practice in Finland.14 It builds on national Finnish recommendations for lifestyle counselling, which emphasise assessing the initial situation, information exchange, goal setting, planning, monitoring and feedback.14 Smart Family translates these components into a practical, multilevel and family-centered counselling approach for professionals working with children aged 0–12 years and their families.15,16

In Finland, Smart Family is integrated into the daily work of professionals in maternity and child welfare clinics, schools, early childhood education, and oral health services, primarily through public health nurses, reaching approximately 90% of Finnish families. The approach in the Smart Family practice recognises that immediate biometric changes, such as weight reduction, are difficult to achieve and measure in the short term, and therefore priorities initiating a process of positive development.15,16 It trains professionals to use motivational interviewing, recognise families’ strengths and resources, and support autonomy and self-efficacy in lifestyle choices. The practice includes structured and semi-structured counselling tools, such as visual self-assessment instruments, goal-setting worksheets and thematic materials, which translate its theoretical basis into concrete family-centered counselling interactions.15,16 National development, professional training and materials are funded by the non-governmental Finnish Heart Association, with partial external public-sector and project-based support.17

Smart Family is informed by evidence from the STRIP study, which showed that sustained and repeated lifestyle counselling can lead to lasting improvements in cardiovascular risk factors in children and families.18,19 It draws on health psychology theories and a strength-based approach to lifestyle counselling.20,21 Early implementation and evaluation studies suggest that Smart Family tools can help initiate conversations about physical activity and dietary habits, and that parents supported by trained public health nurses more strongly perceived that their family's lifestyle-related strengths were recognised compared with usual counselling.22,23 Recognising these strengths may support self-efficacy and autonomy, both established predictors of sustained behaviour change.20,24,25

Translating these mechanisms into new national and cultural contexts is not straightforward. Most implementation efforts fail before any service reaches its intended recipients, and the completeness of pre-implementation activity has been shown to predict whether programmes start up and are delivered competently. In an analysis of 1,287 sites across twenty-seven evidence-informed programmes, pre-implementation process fidelity was significantly associated with these downstream milestones.26

This study examines the pre-implementation planning of the Finnish Smart Family practice across six European countries: Croatia, Greece, Lithuania, Poland, Slovenia, and Spain. The study aims to:

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  Examine how a common implementation strategy was used to prepare country-specific implementation plans.

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  Compare the baseline situations of lifestyle counselling provision, perceived facilitators and barriers, and proposed adaptations across the participating countries.

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  Identify lessons for planning the transfer of evidence-based best practices in health promotion across different countries and contexts.

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  The study aims to generate implementation knowledge on how evidence-based practices can be prepared for transfer across diverse contexts. Outcomes from the implementation phase will be reported separately.

Health promotion activities are often strengthened through project-based development,30 but fixed schedules and funding periods require effective planning and structured implementation. Carefully designed implementation strategies can enhance implementation success,11,27,31,32 and pre-implementation is a consequential phase in which contextual determinants of later outcomes are established.27,33,34 This study suggests that pre-implementation can function not merely as preparation, but as a mechanism for structuring and comparing the transfer of best practices across countries. The previously tested CHRODIS PLUS implementation strategy11,27 provided a framework for systematically analysing baseline situations and planning the context-sensitive transfer of Smart Family across six countries. Shared templates supported comparability by identifying common implementation needs and context-specific differences, while ongoing mentoring from the original Finnish developers helped partners distinguish the core elements of Smart Family from local adaptations and translate them into feasible plans. Transparent reporting of this process also addresses a recognised gap in how transfers of public health best practices are described.34

Implementing best practices is inherently complex,35 particularly across national and cultural contexts. The participating countries differed in their settings, target populations, professional roles, governance, institutional mandates, and data availability. Lifestyle counselling was delivered in both healthcare and education by multiple professional groups but was not consistently supported by national or institutional guidance or systematic training. However, professionals already working with children and families provided a basis for developing motivational, strength-based lifestyle counselling.

Country-level differences shaped what was feasible. Countries with established programmes or structured prevention pathways could integrate Smart Family into routine work, whereas others relied more on project-based delivery. Implementing teams also differed in their institutional mandates, ranging from universities and municipalities to national research institutes under ministries. These findings are consistent with implementation science literature showing that context and system complexity influence feasibility and adaptation.35,36

Planning to integrate Smart Family into established health promotion frameworks and professional education structures may promote local ownership and create more favourable conditions for longer-term continuity. Moreover, identifying ongoing or upcoming initiatives during the planning phase may allow the implementation to be aligned with existing developments, making it timelier and more efficient, although these outcomes require subsequent evaluation.

These findings illustrate the importance of understanding the “black box” between research and practice. Implementation science seeks to explain how evidence-based interventions can be integrated into routine practice, considering contextual constraints, organizational capacities, and professional roles.36,37 The structured pre-implementation process used in this study enabled countries to identify contextual factors early and tailor their plans accordingly, consistent with previous research.38

Cross-country exchange can support learning and contextual adaptation by facilitating the exchange of knowledge and ideas.39 In this study, shared learning helped identify potentially feasible implementation pathways and develop a common understanding of how Smart Family might be adapted while retaining its core principle: the motivational, strength-based approach to lifestyle counselling. Understanding the core of the best practice in terms of why it works, what principles underpin it, and under which conditions it can achieve similar outcomes elsewhere is important. Transferring a Finnish best practice requires cultural and contextual adaptation to succeed in other countries. The Finnish partners played a significant role by providing guidance, templates, materials, and feedback on implementation plans. This support helped implementing teams understand that transferring Smart Family required changes in professional counselling practices, not only the provision of health information or materials to families. The findings suggest that support from original developers may facilitate transfer to new contexts, consistent with previous studies using similar methodology,11,27 but requires further investigation.

All piloting countries planned to promote multisectoral collaboration by engaging professionals from health, education, and community sectors with the intention to build supportive networks around families and contribute to health-promoting communities and environments. Such multisectoral action is widely recommended in childhood obesity prevention.8 However, as this study focuses on pre-implementation planning documents and processes, the findings do not establish whether the planned adaptations will result in successful implementation, sustained delivery, or long-term transferability of the Smart Family practice. Rather, they identify conditions and mechanisms that may support these outcomes. Implementation fidelity, the effects of local adaptations, sustainability, and longer-term integration into routine practice should therefore be examined in subsequent implementation and outcome evaluations.

The shared indicator may support future evaluation of fidelity to the core elements of the Smart Family practice by focusing on the counselling process rather than on context-specific outputs. As a self-reported measure, it may be subject to social desirability bias and does not capture observed counselling practice or family-level outcomes. It is therefore appropriate to the pre-implementation and early implementation context and should be complemented by observational and outcome measures in subsequent evaluation.

This study has several limitations. EU Joint Actions are not primarily research projects, and the analysed documents were produced to support implementation planning rather than research. Reporting depth and specificity varies between countries, which may increase the risk of selective reporting and limit the precision of cross-country comparisons. The SWOT analyses were also country-generated, and the classification of factors reflected country teams’ own interpretations of their contexts. In addition, the authors functioned as implementers or work package leaders, which may have introduced insider or observer bias. Finally, although common templates were used, a strict protocol was not applied to preserve flexibility. This flexibility supported local adaptation but made standardised cross-country transfer more demanding.

Differences in service structures, professional roles, and local governance added further complexity to the planning of the implementation across countries. The cross-country variation suggests that balancing local adaptation with fidelity to the core elements of the practice is most likely to remain a central challenge for sustainable cross-country transfer. Subsequent phases should include systematic documentation of adaptations to determine their implications for fidelity, feasibility, and sustainability. The template-driven approach used in this study could also be further developed into a transferable toolkit to support future international implementation projects.

The planning process highlights the tension between adaptation and fidelity: how to tailor a best practice to new contexts while retaining its core identity. The sustainability and long-term feasibility of these adaptations should be assessed in future evaluations.

The pre-implementation phase of the Smart Family implementation strategy appeared useful for structuring planning across six European countries with diverse health-system configurations. It enabled implementing teams to define goals and actions, consider local contexts and develop country-specific implementation plans using a shared framework. To our knowledge, this represents one of the first simultaneous multi-country applications of the CHRODIS PLUS implementation strategy to a family-oriented lifestyle counselling practice. Across countries, the plans shared an emphasis on strengthening professionals’ counselling competence, supporting families, and integrating Smart Family activities into existing service pathways.

There is no online material available for replication. For additional content, please contact the author.

Jorge Marcos-Marcos.

The corresponding author, on behalf of the other authors guarantee the accuracy, transparency and honesty of the data and information contained in the study, that no relevant information has been omitted and that all discrepancies between authors have been adequately resolved and described.

N. Savolainen: study conception and design, data gathering, data analysis and interpretation, article writing and critical reviewing. M. Lang Morović: study conception and design, data gathering, data analysis and interpretation, article writing and critical reviewing. S. Meštrić: study conception and design, data gathering, data analysis and interpretation, article writing and critical reviewing. E. Magriplis: study conception and design, data gathering, data analysis and interpretation, article writing and critical reviewing. M.J. Ramos Monserrat: study conception and design, data gathering, data analysis and interpretation, article writing and critical reviewing. M. Mutter: study conception and design, data gathering, data analysis and interpretation, article writing and critical reviewing. T. Sainio: study conception and design, data gathering, data analysis and interpretation, article writing and critical reviewing. E. Koivurinta: data curation, editing, reviewing. H. Kuusipalo: resources and supervision, data analysis and interpretation. J. Nowak: study conception and design, data gathering, data analysis and interpretation, article writing and critical reviewing. P. Mäki: study conception and design, data gathering, data analysis and interpretation, article writing and critical reviewing. All authors have read and agreed to the published version of the manuscript.

The authors would like to acknowledge Professor Apostolos Vantarakis from the University of Patras for his work as a leader of the Joint Action Health4EUKids and the following people in addition to the authors, who participated in the project group of Work Package 6 in Health4EUKids: Kati Kuisma, Carmen Ortiz Martínez, Sabina Torne, María Belén Peris, Agata Szymczak, Anja Bohinec, Katarzyna Brukało, Vasiliki Iliopoulou, Georgios Karydas, Kyriaki Premtou, Lamprini Lachanioti and Tautvydas Lukavicius.

The authors declare financial support was received for the research, authorship, and publication of this article. Project: Health4EUKids, received funding from the European Union's EU4HEALTH Program under the Grant Agreement no 101082462.

None.