RESUMO
In the experimental group, the average scores of knowledge, constructs of theory of planned behavior, nutrition, and walking had a significant enhancement compared to the control group after the educational intervention. After the intervention, the value of the lumbar spine bone mineral density T-score in the experimental group increased, while in the control group, it decreased. INTRODUCTION: Osteoporosis is a global public health problem currently affecting millions of people worldwide and in Iran. This study was conducted to assess the effect of an educational intervention based on the theory of planned behavior on the prevention of osteoporosis in postmenopausal women. METHODS: This quasi-experimental study was performed on 160 women aging over 50 who were referred to health centers in Fasa City, Iran, in 2019. A simple random sampling method was applied to assign the participants into control and intervention groups (80 participants for each group). Data were gathered by questionnaires arranged based on the constructs of the theory of planned behavior, nutrition performance, and walking performance. The educational intervention included seven 50-minute educational sessions. The obtained data were analyzed using SPSS 22 software and Chi-square test, independent T-test, and paired T-test, and the significance level was considered 0.05. RESULTS: The mean ages of the studied participants in the experimental and control groups were 59.18 ± 6.56 and 57.92 ± 5.70, respectively. In the experimental group, the average scores of knowledge, constructs of the theory of planned behavior, nutrition performance, and walking performance had a significant enhancement compared to the control group one year after the intervention (p < 0.001). At 12 months after the intervention, the value of the lumbar spine bone mineral density T-score in the experimental group increased, while in the control group, it reduced (p < 0.001). CONCLUSIONS: The theory of planned behavior affected nutrition and walking performance in osteoporosis prevention of subjects. This theory can be used as a framework for designing and performing educational interventions for preventing osteoporosis and promoting women's health.