Development and validation of a healthy diet and physical activity tool based on health action process approach among patients undergone bariatric surgery

Background The purpose of this study was to develop and evaluate the validity and reliability of a healthy diet and physical activity assessment tool among patients one year after bariatric surgery based on Health Action Process Approach. Methods We compiled 53 items based on healthy diet and physical activity behaviors among patients undergone bariatric surgery through reviewing the literature. Using quantitative and qualitative methods, and a panel of experts, we evaluated the face and content validities of the tool. The reliability was evaluated by Intra-class correlation coefficient and Cronbach’s alpha. Results The content validity ratio and the content validity index were 0.62 and 0.79, respectively. Exploratory factor analysis showed seven factors, including risk perception, outcome expectations, task self-efficacy, coping, recovery self-efficacy, action planning, coping planning, and behavioral intentions. The Intra-class correlation coefficient was between 0.8 and 0.91; and Cronbach’s alpha for different constructs was between 0.8 and 0.95. Conclusion The findings showed that the constructs of the Health Action Process Approach tool regarding healthy diet and physical activity had adequate validity and reliability in bariatric surgery patients.