Nowadays, population ageing represents a major social and public health challenge. It is characterised in particular by an increase in the vulnerability of seniors to physiological and metabolic disorders which may be due to poor diet. Different factors can be linked to this malnutrition: socio-economic context, sensory deficit, loss of appetite, oral problems or even reduced mobility. If preventive nutrition throughout life is essential in limiting the occurrence of diseases linked to ageing, it is also essential to be able to offer a specific diet adapted to seniors (sensory and nutritional enrichment, modified textures, adapted portions, etc. ) in order to prevent these disorders. In this context, this project aims to develop a new approach integrating the involvement of key players (from farmers to seniors) during the design and development phases of food products adapted for seniors. The objective will be to take into account multiple constraints related to the food product to be designed (agronomic, nutritional, technological or sensory), but also related to the multiplicity of actors involved. Participatory research will be conducted with the actors of this food system: farmers, food science researchers, culinary chefs, sociologists, dieticians and non-dependent seniors, in order to better understand and integrate their behaviours, needs, preferences and to identify levers to develop adapted food.Different associations will be involved in the project: Alim50+ for séniors, Institut Paul Bocuse for chefs and Terre et Cité for farmers. This study will be a proof of concept for the implementation of participatory research to design healthy, sustainable and appreciated food products, integrating the stages of multi-stakeholder ideation and co-creation, the construction and implementation of a dissemination and communication plan for the results, as well as the validation of the acquisition of knowledge by the stakeholders involved.