SMARTer Weight Loss Management

Participant percent change in weight (kg) from baseline to 6-months.

Participant change in weight (kg) from baseline to 6-months.

Costs of SMARTer versus DPP versus Control implementation. We will utilize a micro-costing approach to capture all costs associated with the implementation of the treatment arms.

Explore whether SMARTer stepped care treatment produces greater weight-loss (percent change) from baseline to 12-months and is noninferior to DPP

Explore whether SMARTer stepped care treatment produces greater weight-loss (difference in kilograms) from baseline to 12-months and is noninferior to DPP

Interaction effect between intervention group (SMARTer vs DPP vs Control) and food insecurity on percent weight loss at 6 months, estimated using a linear regression interaction term (β coefficient). Food insecurity will be assessed using a validated 2-item screener based on the U.S. Household Food Security Survey Module, consisting of two items: (1) worry that food would run out and (2) food not lasting. Response options are "Often true," "Sometimes true," and "Never true." Responses will be scored dichotomously (food insecure vs food secure), with food insecurity defined as ≥1 response of "Often true" or "Sometimes true." Percent weight loss will be calculated as percent change in body weight from baseline to 6 months.

An interaction effect between intervention group (SMARTer vs DPP vs Control) and neighborhood deprivation on percent weight loss at 6 months will be estimated using a linear regression model with an interaction term (β coefficient). Neighborhood deprivation will be assessed using a Neighborhood Deprivation Index (NDI) derived from U.S. Census tract-level socioeconomic indicators obtained from the American Community Survey, following methods developed by Diez Roux and colleagues. The NDI will be expressed as a standardized continuous score (z-score), with higher values indicating greater neighborhood deprivation. Percent weight loss will be calculated as percent change in body weight from baseline to 6 months.

Interaction effect between intervention group (SMARTer vs DPP vs Control) and technology literacy on percent weight loss at 6 months, estimated using a linear regression interaction term (β coefficient). Technology literacy will be assessed using the eHealth Literacy Scale (eHEALS; 8-item measure) total score (range: 8-40), with higher scores indicating greater perceived eHealth literacy. Percent weight loss will be calculated as percent change in body weight from baseline to 6 months.

Interaction effect between intervention group (SMARTer vs DPP vs Control) and executive functioning on percent weight loss at 6 months, estimated using a linear regression interaction term (β coefficient). Executive functioning will be assessed using the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) Global Executive Composite (GEC) T-score (standardized score; mean = 50, SD = 10), with higher scores indicating greater executive dysfunction. Percent weight loss will be calculated as percent change in body weight from baseline to 6 months.

Interaction effect between intervention group (SMARTer vs DPP vs Control) and emotional eating on percent weight loss at 6 months, estimated using a linear regression interaction term (β coefficient). Emotional eating will be assessed using the Palatable Eating Motives Scale (PEMS) Coping subscale mean score (range: 1-5), with higher scores indicating greater eating in response to negative emotions. Percent weight loss will be calculated as percent change in body weight from baseline to 6 months.

Indirect effect of intervention group (SMARTer vs DPP vs Control) on percent weight loss at 6 months through change in negative affect, estimated using mediation analysis (indirect effect coefficient). Negative affect will be assessed using the Positive and Negative Affect Schedule (PANAS) Negative Affect subscale score (range: 10-50), with higher scores indicating greater negative affect. Change will be calculated from baseline to follow-up assessments.

Indirect effect of intervention group (SMARTer vs DPP vs Control) on percent weight loss at 6 months through change in craving, estimated using mediation analysis (indirect effect coefficient). Craving will be assessed using a 1-item visual analogue scale (VAS) (range: 0-100), with higher scores indicating greater craving. Change will be calculated from baseline to follow-up assessments.

Indirect effect of intervention group (SMARTer vs DPP vs Control) on percent weight loss at 6 months through change in reward-based eating, estimated using mediation analysis (indirect effect coefficient). Reward-based eating will be assessed using the Reward-Based Eating Drive (RED) scale total score (continuous; higher scores indicate greater reward-driven eating). Change will be calculated from baseline to 6 months.

Indirect effect of intervention group (SMARTer vs DPP vs Control) on percent weight loss at 6 months through change in inhibitory control, estimated using mediation analysis (indirect effect coefficient). Inhibitory control will be assessed using the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) Inhibit subscale T-score (mean = 50, SD = 10), with higher scores indicating poorer inhibitory control. Change will be calculated from baseline to 6 months.