Introduction: Unhealthy nutrition increases the risk of diseases incidence. Some researchers suggest that the interventional programs related to the prevention of chronic diseases including preventive nutritious recommendation should be started in childhood period especially in schools. The purpose of this study was to assess the effectiveness of an educational health intervention based on the Health Belief Model (HBM) in order to reduce junk foods consumption among the primary school children of Araak / Iran (2003-2004).
Materials and Methods: The present double blind randomized semi-experimental study was carried out in the form of a clinical trial on 1200 students in two groups called the experiment and the control (600 in each) from schools randomly selected in two stages, classification and cluster sampling. The study of variables was comparably assessed before and three months after the educational intervention both in the experiment group and in the control one. In the experiment group, the educational intervention was based on HBM framework during a three-month period, in which, the educational messages were designed to increase the students' perception of diseases, susceptibility, severity and its preventive methods, as well as, the benefits and barriers of nourishing behaviors, and also self efficacy. But in the control group, the educational intervention was based on the current methods. Two questionnaires and a check list were used for data gathering. Frequency matching method was used to match the two groups in terms of age, gender, educational degree and social class. The reliability of the questions was determined by "test retest". Data were analyzed by using χ
2, McNemar, ANOVA, Pooled t-test, Paired t-test and followed by scheffe test for multiple comparisons.
Results: The mean age of the students (50% male and 50% female) was 8.63±0.092. Before the intervention, there was no significant difference regarding the socioeconomic class, age, gender, educational degree and the average expenses of the consumed junk foods between the two groups. Also before the intervention, the results showed that 15.6% of the experiment group and 12.3% of the control group didn't use to have breakfast. After the intervention, these values were reduced to 11% and 13.6% in the two groups, respectively. The difference in the experiment group was significant (P<0.05), but in the control group, it wasn't statistically significant (P=0.566).In baseline, 71.6% of the experiment group and 59.1% of the control group were daily consuming junk foods (p<0.001). After the intervention, these figures changed into 62.9% and 67.9%, respectively (p<0.05). Also the average expenses of the consumed junk foods from October to May increased from 44.12 to 46.02 in the experiment group and from 41.29 to 54.59 in the control group. In other words, the increase in the experiment group was much less (1.6) than in the control group (p=0.05). After the intervention, no significant difference was observed or reported in the number of the consumers of the carbonated beverages in the two groups (p=0.204).
Conclusion: The results of current study approved the existence of unhealthy nutritious behaviors among the primary school children, and that applying HBM framework was useful to modify some of these behaviors in a three-month occasion. Our findings also supported the feasibility of an educational health program based on HBM as well as welfare authorities' role in order to induce behavior changes against unhealthy nutrition in primary school children.