Nudge-based intervention to promote vegetable consumption in the school meal: a nonrandomized community trial

Purpose This study aimed to evaluate the effect of nudge-based interventions on the acceptance of vegetables in school meals in a Brazilian public school. Design/methodology/approach A non-randomized community trial with historical control was conducted among elementary school children aged 7–12 years (n = 148). Data were collected using self-administered electronic questionnaires. The four-week intervention used nudge strategies to encourage consumption of school meals at lunchtime, with an emphasis on vegetable intake. The primary outcome was the weekly vegetable consumption in school meals, and the secondary outcome was the proportion of students who reported being familiar with and having tried the vegetables offered on the school meal. An intention-to-treat approach was applied, and changes in the outcomes after the intervention were assessed using crude and adjusted (sex, age and weight status) mixed models for repeated measures. Findings In the post-intervention study, 135 students were examined. Following the intervention, the odds of consuming vegetables at school at least once a week more than doubled (OR = 2.3; 95% confidence interval = 1.6; 3.3). Students also reported greater willingness to try new vegetables among those included in the school meal. Practical implications The positive changes observed in school meal and vegetable consumption among elementary school children indicated that simple, low-cost and easily replicable strategies can reinforce the National School Feeding Program in promoting nutrition education and healthy eating. Originality/value This study adds to the evidence on the use of nudge strategies in middle-income countries and provides insights into their effect in diverse school food environments.