Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Andrea Paiva


Despite significant public health efforts, obesity remains a stagnant outcome comprised of multiple health behaviors including fruit and vegetable intake (FV) and physical activity (PA). Existing research has provided correlates of FV and PA behaviors over development, with secular trends towards acquiring negative health behaviors (e.g., sedentary behaviors). This study examined demographic and dynamic predictors of FV and PA regression at one-year post-intervention within three samples including middle school, high school, and college. Regression is defined using the Transtheoretical Model (TTM) as being in Action or Maintenance at baseline and regressing to a pre-Action stage at one-year follow-up. The novel phenomenon of coregression, the likelihood of regressing on a second behavior given a change in the first, was explored within each sample. Results of univariate and multivariate logistic regressions produced odds ratios that suggest inconsistent demographic but reliable dynamic predictors of FV and PA regression within each sample. Univariate logistic regressions revealed co-regression for FV and PA among middle school and college samples, but not the high school sample. These results indicate that existing behaviors, decisional balance variables (i.e., “Pros”), and self-efficacy are the most salient predictors of regression. The exploration of co-regression as a novel phenomenon provides a foundation for future research in the field. Implications for this study include the tailoring of individualized evidence-based interventions and new directions for public health research.