Objectives: We examined perceived behavior change since implementation of physical distancing restrictions and identified modifiable (self-rated health, resilience, depressive symptoms, social support and subjective wellbeing) and non-modifiable (demographics) risk/protective factors. Methods: A representative US sample (N = 362) completed an online survey about potential risk/protective factors and health behaviors prior to the pandemic and after implemented/recommended restrictions. We assessed change in perceived health behaviors prior to and following introduction of COVID-19. We conducted hierarchical linear regression to explore and identify risk/protective factors related to physical activity, diet quality, and social isolation. Results: There have been substantial decreases in physical activity and increases in sedentary behavior and social isolation, but no changes in diet quality since COVID-19. We identified modifiable and non-modifiable factors associated with each health behavior. Conclusions: Negative effects indicate the need for universal intervention to promote health behaviors. Inequalities in health behaviors among vulnerable populations may be exacerbated since COVID-19, suggesting need for targeted invention. Social support may be a mechanism to promote health behaviors. We suggest scaling out effective health behavior interventions with the same intensity in which physical distancing recommendations were implemented.