Background: There is an increasing concern regarding the impacts of food choices in the environment. Therefore, in order to plan actions to promote more sustainable diets, it is crucial to understand the influence of environmental and political determinants on people’s food choices. Objective: This work aimed at studying the extent to which environmental and political determinants influence people’s food choices in a sample of the Portuguese population. Methods: A descriptive cross-sectional study was undertaken on a non-probabilistic sample of 1314 participants living in the Centre of Portugal. The questionnaires were applied after informed consent only to adults (aged 18 or over) and the data were collected from January and December 2017 among the Portuguese population. Results: The participants’ food choices were, in general, influenced by environmental and political determinants (0.77 ± 0.53, in a scale from -2 to +2). It was also observed that the elderly, men and the participants who had a university degree were more influenced by these determinants. These findings were similar for those who lived in urban areas, the retired, the participants who had a professional activity or studies in agriculture areas and those who were responsible for buying their own food. Furthermore, there were found significant differences between age groups, genders and the levels of education. There were also observed significant differences between the different living environments, professional status, regarding the areas of work or studies and also between the participants who were responsible for buying their one food and the ones who were not. These findings are very important because they highlight the complicity of people’s food choices and are determinant for the development of strategies that can improve people’s eating habits. Conclusion: This paper fulfills an identified need to study the environmental and political determinants underlying the Portuguese food choices.