Effect and process evaluation of a real-world school garden program on vegetable consumption and its determinants in...

This study aimed to investigate the effectiveness of a school garden program on children's vegetable consumption and determinants and to gain insight into the process of the program.

The "Taste Garden" is a real-world nine-week school garden program developed and implemented by a local organization. A total of 350 children (149 intervention group, 201 control group) filled out questionnaires on vegetable consumption, determinants and process of the program. Additionally, teachers filled out a process evaluation questionnaire. For effect evaluation, interaction effects (time x group) were considered, using multilevel repeated measures analyses in MLwiN 3.02. Interaction effects were repeated, taking into account quality of implementation (time x implementation group). Process evaluation was descriptively assessed with SPSS 24.0.

Overall, beside some practical concerns of teachers, the program was well perceived by teachers and children. However, an intervention effect of "The Taste Garden" was only found for knowledge (p = 0.02), with a very small effect size (0.55%). When taking into account implementation quality, only small effects were found for awareness (p between 0.005 and 0.007 and an effect size of 0.63%) and knowledge (p between 0.04 and 0.09 and an effect size of 0.65%).

Evaluation of the real-world "Taste Garden" program, which was positively perceived by teachers, showed no effects on vegetable consumption and small effects on its determinants. Adaptations of the current format and longer follow-up periods are therefore recommended.