The planetary health diet is a proposition of a diet that is healthy for both people and the environment. The aim of this study was to investigate the nutritional behaviours among people who follow the planetary health diet and those who do not and assess the source of motivation that drives a willingness to follow sustainable diet guidelines. Using a self-administered questionnaire, data were collected from Polish adult volunteers. For analysis, respondents were divided into the following two groups: those following a planetary health diet (PD) and those who were not (O). Of the 216 respondents, 39.4% followed the PD. Non-adherence to the PD was linked to a higher prevalence of overweight and obesity. Taste was the most important factor for both groups during grocery shopping. However, sustainable agriculture and the health benefits of products were significantly more important for the PD followers. It can be concluded that adherence to the planetary diet is associated with lower body mass. This highlights the need for increased awareness and education about a diet's health benefits and environmental impact.
Keywords: Poland; food choices; planetary health diet; public health; self-determination theory.