The present study aimed to evaluate the effect of the school-based educational intervention “FOODcamp” on dietary habits among 6th–7th graders (aged 11–13 years), focusing on the food groups: fruits and vegetables, fish, meat, discretionary food, and sugar-sweetened beverages. In this cluster-based quasi-experimental controlled intervention study, 16 intervention classes (322 children) and 16 control classes (267 children) from nine schools were recruited during the school year 2019–2020. The children were asked to record their food intake for four consecutive days (Wednesday to Saturday) before (baseline) and after (follow-up) attending FOODcamp, using a validated self-administered web-based dietary record. Eligible dietary intake registrations from 124 and 118 children from the control and interventions classes, respectively, were included in the final statistical analysis. Hierarchical mixed model analysis was used to evaluate the effect of the intervention. No statistically significant effects of participating in FOODcamp were found on the average food intake of the food groups eaten regularly (vegetables, fruit, vegetables/fruit/juice combined, or meat) (p> 0.05). Among the food groups not eaten regularly (fish, discretionary foods, and sugar-sweetened beverages), a non-significant tendency to lower odds of consuming sugar-sweetened beverages from baseline to follow-up (OR = 0.512; 95% CI: 0.261–1.003;p= 0.0510) was seen among FOODcamp participants compared to control participants. In conclusion, this study found no effect of the educational intervention FOODcamp on the dietary intake of vegetables, fruit, vegetable/fruit/juice combined, meat, fish, or sugar-sweetened beverages. The intake frequency of sugar-sweetened beverages tended to decrease among FOODcamp participants.