Principal Findings
This study investigated whether engagement with different tailored behavioral sessions, measured in terms of log-in status and duration, was associated with improvements in MVPA among African American families. Among parents, logging into the PA session was not associated with greater MVPA. However, consistent with our hypothesis, MVPA did increase with greater log-in duration for the PA and sedentary activity sessions, suggesting that greater exposure to the tailored PA-related content had a positive impact on parents’ MVPA. Surprisingly, the results also indicated that logging into the fast food session was associated with greater MVPA, but log-in duration for the fast food session was not significantly associated with parent MVPA. Consistent with past reviews, which have found that the clustering effects of PA and diet are complex [The results also indicated that engagement with different behavioral content sessions was not significantly related to MVPA after the web-based intervention among adolescents, suggesting that the effects observed in parents did not carry over to their adolescent children. Although parent involvement is viewed as an important component for adolescent eHealth interventions [