## 4 Discussion
The awareness and knowledge of environmental, agricultural and health problems of the respondents was found to be at a low (31%) and sufficient (50%) level. A small percentage of respondents had knowledge at a very low (5%) or high (14%) level. The results of none of the respondents allowed us to conclude that their level of knowledge is at a very high level, which means that there is a need of a better educational system. These findings are connected with the research conducted in the Medical University of Silesia, which showed that there is a necessity to increase the awareness and appropriate nutrition intake of future medical workers who will be responsible for public health in their professional life [37]. The public procurement and catering services stakeholders are also important actors in the public health sector, as public canteens can improve or worsen everyday dietary habits, especially in schools and kindergartens [37; 38; 39]. Not only high-quality nutrition is crucial for childhood growth and development, but it is also greatly relevant to mental well-being [40]. Green public procurement in canteens, as written in the introduction, can greatly influence sustainable and healthy decisions in the public health sector. An intervention study among students and staff at a Dutch university found that greater knowledge of healthy or sustainable food choices is associated with eating meals with a more environmentally friendly impact. The correlation between pre-intervention knowledge and observed dietary alteration was significant, especially concerning the CO2 and land use impacts of food choices [41]. The study demonstrates that the education program for PPCS stakeholders has to be complex, and it should connect different aspects of sustainability in the food systems. In our research, the majority of the respondents knew the proper definition of climate change, sustainable development, and sustainable fishing, but only a minority were able to recognise the problems associated with the low sustainability of food systems. Only few respondents knew that nitrogen fertilisers (32%) increased industrial livestock breeding (14%), while diet (12%) and agricultural intensification (11%) were also responsible for climate change. The consequences of climate change are connected to difficulties in agriculture was known to only 33% of participants and only 31% linked it to reduced food security. The least important environmental problem to respondents was overfishing of the seas and oceans (3.0). None of the respondents have indicated such an environmental problem as soil degradation due to monocultures, but 31% incorrectly chose the development of agriculture through monocultures as an element of sustainable development. Sustainable eating is not only about rules and regulations, but it should be an enjoyable and tasty experience with traditional and cultural likings respected [42]. The general knowledge is not the only element of sustainable and healthy choices [43]. Although it is necessary, as the Polish Supreme Audit Office reported a lack of knowledge among employees and decision makers of canteens about balanced school meals and showed that none of the inspected establishments provided lunches that met 100 per cent of the appropriate nutritional standards for children and young people. All assessed menus were found to be too high in protein and carbohydrates, and over 85 per cent also in fat [44]. The most common changes suggested by respondents in the survey for the canteens' menus were: more vegetables and vegetable dishes (15%); more fruit (8%); more variety of dishes (6%) and smaller portions (5%). Respondents considered fruit (15%), vegetables (14%), soups (12%), and salads (10%) to be the most environmentally friendly dishes, and at the same time raw salads (32%), soups (25%), fruit (12%), fish (12%), salads (12%), vegetables (10%) and cereals (9%) to be the healthiest ones.