Implementation of health education programs is one of the necessary ways to prevent diabetes in teenagers. The aim of this study is to determine the effect of educational intervention on preventive behaviors of type 2 diabetes based on the health belief model.

This Quasi-experimental study was conducted in 2019 on 143 at-risk high school boys in Khash city (in the southwest of Iran) who were selected by cluster random sampling and were randomly assigned into two groups (70 students in the intervention group, 73 students in the control group). The data collection tool was a questionnaire of demographic characteristics, knowledge, model constructs, and disease prevention behaviors. The educational program was held in 7 one-hour sessions. The control group did not receive any intervention. The data were collected before the intervention, immediately, and three months after the intervention and were analyzed using chi-square test, independent t- test, and two-way repeated measures ANOVA.

The changes in the mean score of knowledge, model constructs, and behavior in the intervention group during three times (before training, immediately, and three months after training) were significant (p<0.001). The average behavior score of the intervention group in the pre-test stage was 17.36 out of 35, which increased to 22.96 immediately after the intervention and declined to 18.57 three months later, but this trend in the control group was decreasing over time.

Considering the effect of the program based on the health belief model in promoting diabetes prevention behaviors in students, it is recommended to design, implement, and evaluate a theory-based program with the aim of controlling and preventing diabetes in adolescents.