Document Type : Research Article (s)


Department of Nursing and Midwifery, Shiraz University of Medical Sciences, Shiraz, IR Iran


Background: The peers play an important role in choosing the foods and shaping the dietary habits. Obesity and many other diseases result from consumption of unhealthy foods by children and adolescents.
Objectives: The aim of this study was to determine the deleterious effect of junk foods on knowledge, attitude and body mass index (BMI) of school students in Shiraz, southern Iran.
Patients and Methods: This study was conducted in two stages and comprised 480 (240 boys and 240 girls) of fifth grade in primary schools from four education and culture districts of Shiraz. The students were selected randomly and divided into two groups of intervention (120 girls and 120 boys in case group) and (120 girls and 120 boys in control group). In the first stage, both case and control groups completed the questionnaire on their knowledge, and attitude, in addition to calculating and recording their BMI. Initially, 3-4 active candidate students were selected from each class and after educating them about disadvantages of junk foods, commissioned them to educate their classmates daily about deleterious impact of such diets. The second stage started after three months when the same questionnaires were recompleted by both case and control groups, while their BMI re-calculated and recorded. The collected data were statistically analyzed using SPSS 15, chi square, paired t test, ANOVA and Post hoc test.
Results: The results showed that, before intervention, out of 480 girls and boys, 13.0% were thin, 38.2% had normal weight, and 11.9% were overweight of whom 36.9% were obese. By comparing the average weight and height for girls and boys (case and control group), only in the region-1, there was a statistically significant difference in the mean weight (P = 0.002) and height (P = 0.015) of the girls in control and in the case group. Case groups from all four regions were overweight but without any statistically significant difference (P = 0.381).However, after intervention, a significant difference in overweight was found between case and control groups (P = 0.041). There was a significant relationship (P < 0.05) in comparing the score mean difference of attitude of students’ girls and boys (case-control) in four regions before intervention. The attitude score of girls was better than the boys. There was no significant correlation (P > 0.05) between average knowledge scores of girls and boys (case and control) before and after intervention and attitude after intervention.
Conclusions: Children spend a long time at schools which are ideal places for education. The peers chosen for this study proved to be highly successful in educating their classmates in cautioning them against unhealthy diets, an approach of potential educational Value.