Sustainable food systems have the potential to protect humans and planet health. Green public procurement (GPP) is a tool for the sustainable transformation. In Poland, the share of GPP is extremely low. As part of the StratKIT project, a survey-based research study was carried out in the city of Rybnik (Silesia Region). The aim of this paper is to diagnose the level of awareness in the field of sustainable development of the project stakeholders, and to propose further sustainable actions related to GPP in Poland. The survey was conducted in social care homes and two primary schools. Statistical analyses were performed using SPSS 24 software. The results show that the level of education has an impact on the assessment of the environment, and that the place of residency interferes with the level of environmental, organic and nutritional knowledge. Correlational analysis showed no statistically significant relationships between age, level of education, place of residence and willingness to introduce action connected to GPP (e.g., organic food). In conclusion, there is a need for an appropriate educational program for the public procurement and catering services (PPCS) sector, teaching about advantages of GPP for the food systems in connection to sustainable agriculture, consumption and climate actions.