Stanford Healthy Heart Study

This randomized trial will test the efficacy and cost-effectiveness of novel modules administered prior to weight loss that are explicitly designed to enhance enjoyment of healthy lifestyle behaviors independent of any longer-term health effects, and thus escalate the proportion of individuals sustaining ≥7% weight loss over the long-term. Overweight/obese individuals with elevated blood pressure will be randomized to one of two 12-month weight-management interventions (Fun First or Weight Watchers) and followed for 36 months. For Aim 1 (Primary outcome), we will test whether Fun First is more efficacious than Weight Watchers using a mediator-intervention interaction model with sufficient a priori statistical power for the interaction effect as well as the intervention and mediator main effects. The posited mediator assesses participants' change in enjoyment for four key healthy lifestyle behaviors (healthy eating, physical activity, weighing and self-nurturing) via online survey from 0-2 months. The primary outcome is the proportion of participants who lose a clinically significant amount of initial body weight and maintain it during the trial (i.e., lose \>=7% of their initial body weight from 0-12 months and gain \<=5 lbs from 12-36 months), assessed on clinic scales during in-person visits at the research clinic. Secondary outcomes include the proportion of individuals sustaining ≥7% weight loss over the trial assessed by digital cellular scales in participants' homes and participants' change in systolic blood pressure over the trial assessed at the research clinic. For Aim 2 (Other pre-specified outcomes), we will test whether Fun First is more cost effective than Weight Watchers using both individual-level trial data and systems science modeling for long-term, population-level hypertension and cardiovascular disease incidence, health care and disability costs, and quality-adjusted life-years over the life course.