The DASH Diet Education intervention is a 6-week web-based nutrition education program delivered through the e-Learning Commons (eLC) platform. The program consists of six structured modules focused on evidence-based DASH dietary recommendations and heart-healthy eating behaviors. Content includes dietary quality improvement, meal planning, portion control, label reading, and dietary self-monitoring to support behavior change.

Change in motivation for regulating eating behaviors from baseline to 6 weeks was measured using the Regulation of Eating Behaviors Scale (REBS), a 24-item self-report measure based on Self-Determination Theory. The REBS assesses six types of motivation: Intrinsic Motivation, Integrated Regulation, Identified Regulation, Introjected Regulation, External Regulation, and Amotivation. Items are rated on a 7-point scale. Autonomous motivation is calculated by summing Intrinsic, Integrated, and Identified Regulation subscales; controlled motivation is calculated by summing Introjected, External Regulation, and Amotivation subscales. Both scores range from 12 to 84, with higher scores indicating stronger motivation in the respective category. A self-determination score is calculated from weighted subscale scores, with higher values indicating greater autonomous motivation to regulate eating behaviors.

Change in body weight from baseline to 6 weeks was measured using a calibrated digital scale. Weight was recorded in kilograms (kg). Lower values indicate weight loss.

Change in body mass index (BMI) from baseline to 6 weeks. BMI was calculated using the CDC Adult BMI Calculator based on measured height (cm) and weight (kg). BMI is reported in kg/m², with lower values indicating reduced body weight relative to height. Lower values indicate reductions in body weight relative to height.

Change in waist circumference from baseline to 6 weeks measured in centimeters (cm) using a standardized tape measure. Lower values indicate reduced central adiposity.

Change in waist-to-hip ratio from baseline to 6 weeks. Waist-to-hip ratio was calculated by dividing waist circumference (cm) by hip circumference (cm). Lower values indicate a more favorable body fat distribution and lower cardiometabolic risk.

The Mindful Attention Awareness Scale (MAAS) was administered at baseline and used as a stratification variable for randomization, and was reassessed at 6 weeks to evaluate change in trait mindfulness. The MAAS is a 15-item self-report measure of present-moment attention and awareness. Items are rated on a 6-point scale ranging from 1 (almost always) to 6 (almost never). Total scores range from 15 to 90, with higher scores indicating greater trait mindfulness and present-moment awareness.

Change in retinal carotenoid status from baseline to 6 weeks was measured as macular pigment optical density (MPOD) using customized heterochromatic flicker photometry with a Macular Metrics Densitometer (Macular Metrics, Rehoboth, MA, USA). MPOD reflects concentrations of the dietary carotenoids lutein, zeaxanthin, and meso-zeaxanthin in the retina. Participants adjusted the intensity of alternating blue (460 nm) and green (570 nm) light stimuli to minimize perceived flicker, and measurements were obtained at a retinal eccentricity of 30 minutes. MPOD is reported in optical density units, with higher values indicating greater retinal carotenoid status.

Change in perceived stress from baseline to 6 weeks was measured using the Perceived Stress Scale-10 (PSS-10), a 10-item self-report measure assessing the degree to which individuals perceive situations in their lives as stressful, unpredictable, uncontrollable, and overwhelming. Items are rated on a 5-point scale ranging from 0 (never) to 4 (very often). Total scores are calculated by summing item responses after reverse-scoring positively worded items and range from 0 to 40. Higher scores indicate greater perceived stress.

Change in fasting total cholesterol from baseline to 6 weeks was measured from fasting venous blood samples collected by a trained phlebotomist and analyzed using the Piccolo Xpress analyzer (Abaxis, Union City, CA). Total cholesterol was reported in milligrams per deciliter (mg/dL). Desirable levels are less than 200 mg/dL, borderline high levels are 200-239 mg/dL, and high levels are 240 mg/dL or greater. Lower values indicate improved lipid status.

Change in fasting triglycerides from baseline to 6 weeks was measured from fasting venous blood samples collected by a trained phlebotomist and analyzed using the Piccolo Xpress analyzer (Abaxis, Union City, CA). Triglycerides were reported in milligrams per deciliter (mg/dL). Normal levels are less than 150 mg/dL, borderline high levels are 150-199 mg/dL, high levels are 200-499 mg/dL, and very high levels are 500 mg/dL or greater. Lower values indicate improved lipid status.

Change in fasting low-density lipoprotein cholesterol (LDL-C) from baseline to 6 weeks measured from fasting venous blood samples collected by a trained phlebotomist and analyzed using the Piccolo Xpress analyzer (Abaxis, Union City, CA). LDL-C was reported in milligrams per deciliter (mg/dL). Optimal levels are less than 100 mg/dL, near optimal levels are 100-129 mg/dL, borderline high levels are 130-159 mg/dL, high levels are 160-189 mg/dL, and very high levels are 190 mg/dL or greater. Lower values indicate improved cardiovascular risk profile.

Change in high-density lipoprotein cholesterol (HDL-C) from baseline to 6 weeks was measured from fasting venous blood samples collected by a trained phlebotomist and analyzed using the Piccolo Xpress analyzer (Abaxis, Union City, CA). HDL-C was reported in milligrams per deciliter (mg/dL). Low HDL-C is defined as less than 40 mg/dL for men and less than 50 mg/dL for women. Higher values indicate an improved cardiovascular risk profile

Change in fasting blood glucose from baseline to 6 weeks measured from fasting venous blood samples collected by a trained phlebotomist and analyzed using the Piccolo Xpress analyzer (Abaxis, Union City, CA). Glucose was reported in milligrams per deciliter (mg/dL). Normal fasting glucose ranges from 70-99 mg/dL, prediabetes is defined as 100-125 mg/dL, and diabetes is defined as 126 mg/dL or greater. Lower values indicate improved glycemic status.

EMA engagement was assessed during the 6-week intervention using survey completion metrics, including the number of days with completed EMA responses, average completion rate, time to complete surveys, and the time of day at which responses were submitted. Completion rate was calculated as the percentage of EMA surveys completed out of all EMA prompts delivered, with higher percentages indicating greater responsiveness to real-time data collection.

Recruitment feasibility was assessed during study enrollment. Recruitment rate was calculated as the proportion of screened individuals who met eligibility criteria and enrolled in the study. Higher percentages indicate greater feasibility of identifying and enrolling participants from the target population.

Participant retention assessed during the 6-week intervention. Retention rate was calculated as the proportion of enrolled participants who completed the intervention and attended follow-up assessments. Higher percentages indicate greater acceptability of the intervention and study procedures.

Intervention engagement was assessed during the 6-week intervention using eLearning platform metrics. Engagement was measured by the number of assigned educational modules completed, the proportion of modules completed, and the time spent engaging with intervention content (minutes). Higher values indicate greater engagement with the Mind Your Heart program.

Completion of study assessments was calculated as the proportion of participants who completed anthropometric measurements, blood pressure assessments, blood biomarker collection, dietary records, and questionnaires at baseline and follow-up. Higher percentages indicate greater feasibility of study assessment procedures.