Background and Objectives: Regarding the high prevalence of unhealthy food habits among Iranian children, we aimed to assess the effect of a school-based nutrition education program on nutritional status of primary school students in Shiraz.

Materials and Methods: This randomized educational controlled trial was carried out on 221 primary school age children selected by cluster sampling in the elementary schools of Shiraz-Iran. The intervention consisted of 6 nutrition education sessions carried out through one year for children, using active learning methods. Mothers’ education was carried out in person in both lecture and question-answer sessions also via sending text messages and pamphlets. Weight, height and waist circumference (WC) of children were measured before and after the intervention. Also a 168-item food frequency questionnaire was completed. Two separate nutrition knowledge questionnaires were filled up by children and their mothers. Data were analyzed using SPSS version 16.

Results: 171 children (83 in the case and 88 in the control group), aged 9.5-10.5 years, completed the study. Anthropometric and nutritional knowledge of the participants in both the intervention and control groups was significantly increased. Weight, height, WC and nutritional knowledge increased significantly more in the intervention group compared to the controls. Consumption of fruits and vegetables decreased in the intervention group while plain sugar and fast foods intake increased among the controls. There were no significant differences between the changes in the intake of any of the food groups in the two groups.

Conclusions: In conclusion, the designed nutrition education program could increase students’ nutritional knowledge, and lead to a non-significant change towards reducing the consumption of unhealthy foods such as fast foods, sweets and salty snacks.