Exploring Drivers of Children’s Food Choices: A Multi-Source Process Evaluation of a School-Based Nutrition Education Program

Children’s food choices are shaped early in life through cognitive, social, and environmental influences, yet relatively little is known about how school-based nutrition education supports these processes in routine settings. This study examined mechanisms potentially relevant to children’s food choices using a multi-source process evaluation of the municipal “I Know What I Eat” program implemented in Warsaw primary schools. A prospective observational implementation study was conducted in 81 public schools, covering 198 workshop cycles for students aged 8–9 years. Data were obtained from teacher-observers (n = 198), trained program implementers (n = 6), and implementation records. The evaluation focused on implementation quality, fidelity, acceptability, and mechanisms relevant to food-related decision-making. Quantitative data were analyzed using descriptive statistics, Kruskal–Wallis tests, and Spearman correlations; qualitative comments were examined using content analysis. The program was implemented with high quality and consistency, with mean ratings ranging from 4.88 to 4.96 on a five-point scale and no significant differences by implementer or class size. Qualitative findings indicated that experiential learning, practical food preparation, peer interaction, and active participation supported children’s engagement. These findings suggest that school-based nutrition education can create conditions relevant to food-related decision-making, although direct behavioral measures are needed.