Development and evaluation of social cognitive measures related to adolescent dietary behaviors.

Background: This study aimed to develop and evaluate the reliability and factorial validity, of social-cognitive measures related to adolescent healthy eating behaviors.
Methods: A questionnaire was developed based on constructs from Bandura's Social Cognitive Theory and included the following scales: self-efficacy, intentions (proximal goals), situation (perceived environment), social support, behavioral strategies, outcome expectations and expectancies. The questionnaire was administered with a two week test-retest among secondary school students (n = 173, age = 13.72 ± 1.24). Confirmatory factor analysis was employed to examine model-fit for each scale using multiple indices including: chi-square index, comparative-fit index (CFI), goodness-of-fit index (GFI), and the root mean square error of approximation (RMSEA). Reliability properties were also examined (ICC and Cronbach's alpha).
Results: The reliability and factorial validity of each scale is supported: fit indices suggest each model to be an adequate-to-exact fit to the data; internal consistency was acceptable-to-good (α = 0.65-0.79); rank order repeatability was strong (ICC = 0.81-0.89).
Conclusions and Implications: Results support the reliability and factorial validity of social cognitive scales relating to healthy eating behaviors among adolescents. As such, the developed scales have utility for identifying potential social cognitive correlates of adolescent dietary behavior, mediators of dietary behavior change and validity testing of theoretical models based on Social Cognitive Theory.