The aim of the study was to determine the impact of social media on the food purchasing decisions and dietary attitudes of Polish consumers. Methods: The research was conducted using the diagnostic survey method, employing an online questionnaire technique CAWI (Computer Assisted Web Interview). A total of 1099 adults participated in the study, including 54.23% women and 45.77% men. The survey data were analysed using multidimensional discriminant analysis. Results: The study demonstrated that social media significantly affects the purchasing decisions of Polish consumers regarding food products. The study indicated that there is a gender difference in the impact of social media. Women more often use SM to gain knowledge about food products and shape their dietary attitudes, and they are more susceptible to marketing content. Conclusions: It seems necessary to regulate online advertising and eliminate excessive advertising, as this form of publication in the media is the most effective and has a significant impact on the purchase of food products by Polish consumers. Unrestricted access to content and lack of regulation lead to misinformation, which can result in erroneous purchasing choices.