The current food system is insufficient and unsustainable, generating 17% of the total GHG emissions for animal farming while only supplying 18% of the global calories and 37% of the global proteins. The cultured meat (CM) and cultured seafood (CSF) industry is emerging to meet the growing demand of protein with promises of lower environmental footprint. However, the current knowledge on the impact of this sector is limited, based on developments that have not happened yet and lacking important considerations such as its social impact or its adaptability to current and future demand. Current race-to-market pressures, fueled by recent market approvals overseas, highlight the need to define a roadmap that can develop the sector in an ethical, sustainable and cost-competitive way. This is a unique opportunity for an effective reorganisation of the food system to establish resilient value chains in the EU. Gathering a large set of independent food system actors, FEASTS will provide an unprecedented, unbiased and robust knowledge base for the assessment of the sustainability aspects of the CM/CSF sector by actively promoting multistakeholder engagement and co-creation activities grounded on transparent dialogue and open science practices. It will explore different production methods, product types, supply and value chains as well as business models to provide balanced solutions that are not only sustainable by design and cost-efficient, but also ethically responsible, safe and nutritious, fair and inclusive. FEASTS, designed as a think-tank, adopts a Food Systems Thinking approach and a multidimensional impact assessment including not only LCA, TEA and SLCA of CM/CSF products and their comparison to conventional counterparts but also systems dynamic modelling and integrated scenario analysis that will provide a decision support tool for informed policy- and decision-making in the EU.