The Gray Matters App Targeting Health Behaviors Associated with Alzheimer's Risk: Improvements in Intrinsic Motivation and Impact on Diet Quality and Physical Activity.

Objective: We examine if the Gray Matters intervention (education and behavioral self-monitoring app targeting lifestyle risks for Alzheimer's disease [AD]) affected participants' motivation for change and whether high motivation predicts improved diet and physical activity over 6 months.

Design: In this 6-month randomized controlled trial (treatment n=104; control n=42; assessed pre/post intervention) amotivation, external regulation, identified regulation, and intrinsic motivation were assessed via the Situational Motivation Scale (SIMS). Diet quality was assessed via adherence to the DASH diet, and physical activity was assessed in minutes.

Participants: Eligibility criteria included not having significant cognitive impairment. Participants were aged 39-64 (M = 54.17, SD = 6.9), 66% female, 81% married, 90% White, and 80% had a college degree.

Intervention: Treatment included an activity tracker, Gray Matters app, access to booster sessions, contact with a student health coach, and study website.

Setting: Participants were in the general community.

Results: Independent samples t-tests determined that intrinsic motivation (IM) increased significantly for the treatment group (M = 2.09 SD = 4.82), compared to the control group (M = 1.00 SD = 5.52; t (130) = -3.04, p = .003). Comparing subgroups of people with High vs Low IM we found that High IM males increased vigorous physical activity more than Lower IM males (F(1,42)=5.053, p=.030). Comparing persons aged 58-64 years with High vs Lower IM, High IM persons had less improvement in diet quality F(1,48)=4.538; p=0.038).

Conclusion: RCT results support that the Gray Matters AD-focused intervention increased IM, and IM was associated with improved physical activity and diet quality for some subgroups.