The global food system, responsible for up to 37% of GHG emissions, requires urgent transformation due to challenges from urbanisation and unsustainable diets. Additionally, climate change and biodiversity loss exacerbate the vulnerability of European food systems, as seen in recent climate-related disasters like wildfires and droughts, compounded by disruptions such as the COVID-19 pandemic. Despite food abundance in Europe, food insecurity threatens millions of European citizens, necessitating a comprehensive approach encompassing knowledge, technologies, behaviours, and policies that promote healthier and more sustainable food systems. Given citizen science (CS) as a potent tool for achieving these goals, SPOON takes the innovative approach to food insecurity by employing CS to empower citizens in creating a more inclusive and sustainable food environment. SPOON’s four main aims are to: deepen scientific knowledge about food environments; increase capacity of policymakers in data-driven decision-making; foster cross-sector collaboration; increase agency of citizens to change their food consumption behaviour and local food environments; and foster more confidence in citizens in sharing personal food data. SPOON bridges the intention-action gap towards healthier and more sustainable diets by placing citizens at the forefront of transforming the food system through CS integration. SPOON's conceptual framework centres around six CS Labs in Europe, coordinated by local partners and utilising a multi-actor approach. Citizens engage as both researchers and subjects, testing and validating innovative digital tools to collect, analyse and interpret data on their food consumption behaviors and local food environments to then co-design and run small-scale behaviour change interventions together with other stakeholders. SPOON prioritises GDPR compliance and FAIR principles in its data management.