Up to 50% of obese patients are not interested in, or ready for, weight loss. Clinical practice guidelines clearly recommend that these patients avoid gaining weight. Doing so might contain, or even attenuate, the adverse cardiometabolic risks that will likely accrue with additional weight gain. However, despite the clinical benefits, weight gain prevention interventions are not available in primary care practice. This evidence gap disproportionately affects medically vulnerable populations -- those who are low income, often racial/ethnic minority, and may reside in rural settings. These patients have the highest rates of obesity and weight gain but the least interest in, readiness for, and success with weight loss. The implications for these patients are clear: without intervention, most will continue to gain weight and incur cardiometabolic risks. Our Shape Program trial was the first to evaluate a weight gain prevention intervention in primary practice. Shape's participants were medically vulnerable, overweight and obese Black women who were not explicitly interested in weight loss. The 12-month Shape intervention consisted of tailored behavior change goals, weekly self-monitoring and tailored feedback via interactive voice response and monthly coaching calls from a clinic-based registered dietitian. After 18 months, intervention participants were twice as likel to have maintained their weight, compared to those receiving usual care. Recent analyses show that Shape's weight gain prevention effects have persisted for up to four years. To make Shape consistent with the latest obesity treatment guidelines, a key translational priority is to show tht Shape has generalized effects in a population of impoverished, rural, racially/ethnically diverse adults who are at high cardiometabolic risk. We propose to evaluate the effectiveness of an updated Shape 2 weight gain prevention intervention in a pragmatic trial conducted in a rural community health center system. We will randomize 442 overweight and obese adults to either: 1) usual care, or 2) a 12-month weight gain prevention intervention consisting of self-monitoring and feedback via interactive voice response and/or text messaging, tailored skills training, and responsive coaching from a clinic dietitian. The primary outcome is the prevention of weight gain over 24 months post-baseline. We will also compare the updated Shape 2 intervention to usual care with respect to 24-month changes in cardiometabolic risk markers. Finally, we will evaluate Shape 2's dissemination potential and incremental cost-effectiveness.
Clinical practice guidelines emphasize that weight gain prevention is a key component of comprehensive obesity care, but no evidence-based treatments are available in primary care. This pragmatic effectiveness trial will test a scalable treatment approach for medically vulnerable overweight and obese adults, those who suffer disproportionately from obesity and its health outcomes. The recent AHRQ review on weight gain prevention noted: 'We did not find strong evidence that any strategy prevents weight gain.' We hope to provide that evidence.
