YAHEE

Young Adults in Health-Enhancing Equitable Environments (YAHEE)

Early adulthood is a period of major transitions in life: individuals move out of their parents’ home, start to live alone or with peers, form families and embark on their careers. Lifestyle habits that develop during this phase often persist throughout adulthood and older age. This phase is also often characterised by shifts to less healthy dies and lower levels of physical activity, and an increase in overweight and obesity. This trend has accelerated in recent years: the prevalence of obesity among 18-29 year olds has more than tripled between 2003 and 2023 in Germany, for example. This pattern is particularly pronounced among socio-economically disadvantaged young adults, among whom unhealthy lifestyles, poor physical and mental health, and economic disadvantage are often mutually reinforcing.

The YAHEE project addresses these challenges by: i) assessing diet, physical activity and body weight trajectories of young adults in the French NutriNet-Santé cohort study; ii) examining effects of physical activity and food environments on health by linking cohort and geospatial data; iii) working with adolescents and young adults in participatory citizen science projects to improve the bikeability and walkability of their neighbourhoods; and iv) identifying promising strategies for supporting the adoption of evidence-based food and physical activity policies.

Funder: Federal Ministry of Research, Technology and Space (BMFTR) with co-funding from the European Union through the ERA4Health partnership

Project partners: University Sorbonne Paris Nord, Ghent University, Sciensano, University of Amsterdam, National Cheng Kung University Taiwan, LMU Munich

Project period: 2024-2027

Project website: https://yahee-project.com/

Selected study protocols

• Sell K, Vandevijvere S, Schmitz J, Cardon G, Oppert JM, Goedons B, Anton N, Rehfuess E & von Philipsborn P (shared last authors): Strategies for the adoption of policies for healthy food and physical activity environments: Protocol for a systematic review and best-fit framework synthesis. Open Science Framework (OSF) 2025. https://doi.org/10.17605/OSF.IO/HCGS4
  
  
• Proebstl S, Klinger C, Vandevijvere S, Rehfuess E, Goedons B, Cardon G, Oppert JM, Wahnschaft S, Leibinger A, Maintz EM, von Philipsborn P: Factors shaping the adoption of selected evidence-based food environment policies: a study protocol for policy process analyses through interviews in Belgium and Germany. Open Science Framework (OSF) 2026. https://osf.io/jn89x