Abstract Body (Do not enter title and authors here): Background: Physical inactivity and poor adherence to healthy eating guidelines impact cardiovascular health (CVH) outcomes in African American (AAs). Our randomized controlled trial (RCT) testing the FAITH! App, an mHealth lifestyle intervention, showed efficacy in promoting ideal CVH, particularly diet and physical activity (PA) among AAs, warranting exploration of underlying factors. Psychosocial factors (e.g., self-regulation, self-efficacy, social support) are key to healthy behavior adoption.

Hypothesis: The intervention group would have greater improvements in diet and PA-related psychosocial factors than the control group after using the FAITH! App.

Methods: A 2-arm cluster RCT was conducted among AAs from 16 churches in Minnesota comparing the FAITH! App intervention to a delayed intervention control group. The FAITH! App included culturally relevant, CVH-focused education modules, diet/PA self-monitoring and a sharing board. The outcomes were change in diet and PA self-regulation and self-efficacy (primary) and social support and barriers (secondary) at 6 months post-intervention. The intervention effect was assessed using linear regression.

Results: Sixty-eight participants were included (71% female; mean age [SD]: 54.7 [12.6] years) (Table 1). The intervention group showed a significantly greater increase in diet self-regulation [planning/tracking nutrition] (+0.66, p<.03) and PA self-regulation [step count strategies] (+0.47, p=.003) than the control group. Within groups, the intervention group demonstrated significant improvements across diet and PA self-regulation measures, while the control group showed an improvement only in fruit/vegetable and grain intake. No effect was observed in self-efficacy, social support, or barriers.

Conclusions: Our culturally tailored mHealth lifestyle intervention was associated with notable increases in diet and PA self-regulation, suggesting a potential mechanism by which the FAITH! App improves healthy eating and PA among AAs.