Effect of Education Based on the Theory of Planned Behavior on Health Promoting Behaviors in 12-14-Year-Old Girls

Background: adolescence is one of the most important and valuable times in every person's life. therefore, creating a way to adopt and maintain healthy behaviors, education and health interventions seem to be necessary. the present study was aimed to investigate the effect of planned theory-based education on health promoting behaviors in adolescent girls aged 12-14 years in selected schools in tehran, iran. materials and methods: a quasi-experimental study (n=80) was conducted on female students (first course of secondary education) in tehran's schools in 2016. sample size was estimated based on the mean comparison formula of the two groups. the data gathering tool included health promoting behaviors questionnaire and demographic questionnaire. in the intervention group (n=40), the training (three one-hour sessions) was conducted by the researcher through lecture, question and answer and group discussion. before intervention and two months after the intervention, the intervention group and the control group (n=40) completed the questionnaires twice in a two-month interval. results: the results of independent t-test showed no significant difference in mean and standard deviation of scores of attitude, subjective norms, perceived behavior, behavioral intention and behavior before intervention in the two groups (p> 0.05). independent t-test result showed a significant difference in mean and standard deviation of scores of attitudes, subjective norms and perceived behavior after the intervention (p<0.05). conclusion: the results showed that education based on the theory of planned behavior improved health promoting behaviors of adolescent girls. therefore, it is recommended that schools use theory-based educational programs to increase the health promoting behaviors of adolescent girls.