Background The objective of the study was to evaluate the effectiveness of a school-based physical activity and nutritional behavior intervention, on the reduction of clustering of chronic diseases risk factors among school children. Materials and methods A quasi-experimental school-based intervention was conducted with an intervention group and a control group in the region of Sousse in Tunisia. The intervention was implemented between 2010 and 2013, with data collected at pre and at post intervention. Studied risk factors were: smoking, sedentary behavior, low fruit and vegetable intake and obesity. Odds ratios (ORs) were used to calculate the clustering of two risk factors. We calculated ORs in each group before and after the intervention. Results In the intervention group, the prevalence of adolescents that had no risk factors has significantly increased (p = 0.004). In the control group the prevalence of adolescents carrying two or more risk factors has increased (p = 0.06). The results showed that all risk factors tended to cluster together in both groups. In the intervention group, the calculated OR for smoking and sedentary behavior decreased after assessment (OR = 5.93) as well as the OR for smoking and low fruit and vegetable intake (OR = 3.26). In the control group, all ORs increased, showing an enhancement of the association. Conclusion This study showed the effectiveness of a school-based intervention in reducing the clustering of chronic diseases risk factors.
Keywords: adolescent; chronic diseases; cluster analysis; risk factors.