The Impact of Planned Behavior TheoryBased Education on Female Students’ Obesity-Related Behaviors

Background Adolescence is associated with rapid changes in behavioral patterns, which predispose adolescents to high-risk behaviors, such as immobility and unhealthy eating habits. This study was undertaken to evaluate the impact of an educational intervention based on the Theory of Planned Behavior on high-school female students’ obesity-related behaviors. Methods This was a randomized controlled field trial. A sample of 112 first-year high-school female students was selected through cluster random sampling from high schools located in Nehbandan, Iran. A researcher-made instrument was used for data collection, the validity of which was investigated by assessing its content validity, and its reliability was evaluated by using test-retest methods. The test-retest correlation coefficient of the instrument was 0.7. An educational intervention was developed and implemented based on the theory of planned behaviors. The data were collected at three measurement time points including before, immediately after, and three months after the study intervention. Data analysis was performed using the SPSS software (v. 16.0) through conducting independent-sample t test, repeated-measures analysis of variance, and least significant difference post hoc test at a significance level of 0.05. Results There was no significant difference between the groups regarding the students’ demographic characteristics (P<0.05). The results of the statistical tests revealed that in the experimental group, there was a significant difference among the three measurement time points concerning all constructs of the Theory of Planned Behavior. In the control group, the difference among the three measurement time points was statistically significant only for the scores of subjective norms, perceived behavioral control and behavior (P < 0.05). Conclusions The findings of the current study indicated that educational intervention based on the theory of planned behavior has significant effects on adolescent students’ obesity-related attitude and behavioral intention.