摘要：Objectives. We examined whether adding behavioral weight loss strategies could improve the outcomes of a community weight loss campaign. Methods. Shape Up RI is a 12-week, online, team-based program for health improvement in Rhode Island. In study 1, we randomly assigned participants to the standard Shape Up RI program or to the program plus video lessons on weight loss. In study 2, we randomly assigned participants to the standard program or to the program plus video lessons; daily self-monitoring of weight, eating, and exercise; and computer-generated feedback. Results. Adding video lessons alone (study 1) did not result in significantly improved weight loss (2.0 ±2.8 kg vs 1.4 ±2.9 kg; P = .15). However, when the video lessons were supplemented with self-monitoring and feedback (study 2), the average weight loss more than doubled (3.5 ±3.8 kg vs 1.4 ±2.7 kg; P < .01), and the proportion of individuals achieving a weight loss of 5% or more tripled (40.5% vs 13.2%; P < .01). Participants in study 2 submitted self-monitoring records on 78% of days, and adherence was significantly related to outcome. Conclusions. Adding behavioral strategies to community campaigns may improve weight loss outcomes with minimal additional cost. Given the increasing prevalence of overweight and obesity, it is critical to find cost-effective ways to provide assistance with weight loss to large numbers of individuals. Intensive lifestyle interventions that combine diet, exercise, and behavioral strategies typically produce average weight losses of 7% to 10% of initial body weight (7–10 kg) after approximately 6 to 12 months of treatment 1 , 2 and markedly improve obesity-related comorbidities. 3 – 5 However, intensive lifestyle programs are expensive to administer, are time-intensive, and are accessible to only a small minority of the overweight and obese population. Community weight loss campaigns offer the opportunity to reach large numbers of overweight and obese individuals and engage them in weight loss efforts. Several studies done in the 1980s suggested the potential of team-based competitions for weight loss. 6 – 9 Recently, there has been a resurgence of interest in such team-based approaches, which are now offered on a larger scale via the Internet. A recent example is Shape Up RI (available at www.shapeupri.org ), a self-sustaining, annual community campaign designed to help Rhode Islanders lose weight and increase their physical activity through an online, team-based competition. Shape Up RI, like other similar campaigns, is impressive in its ability to reach and retain large numbers of overweight and obese individuals at minimal cost; however, the weight loss outcomes are modest compared with face-to-face programs 1 , 2 and earlier worksite competitions. 3 – 6 For example, in the 2007 Shape Up RI campaign the 4717 participants in the weight loss component averaged a 3.2 kg weight loss. 10 The challenge moving forward is to maximize the weight losses achieved in this new generation of community-based campaigns without substantially increasing participant burden or delivery cost. Intensive lifestyle programs are derived from social learning theory. 11 These programs have been used in recent clinical trials including Look AHEAD and the Diabetes Prevention Program. 1 , 2 A structured protocol of weekly lessons is available online. 12 Typically, these programs are delivered face-to-face with weekly group or individual meetings for 6–12 months. Key components of these programs include clearly defined goals for weight loss, diet, and physical activity and self-monitoring of these parameters. In addition, social learning theory emphasizes the importance of changing physical, social, and emotional cues that may act as barriers to adopting new behaviors and developing positive reinforcers to sustain new behaviors. In the present 2-part study, we tested the efficacy of incorporating key components of intensive lifestyle programs into the Shape Up RI program. In study 1, we tested the hypothesis that providing participants with the content of the Diabetes Prevention Program behavioral weight loss lessons delivered via the Internet would improve treatment outcomes. In study 2, we tested an enhanced intervention, involving not only Internet behavioral weight loss lessons but also regular self-monitoring of diet, activity, and body weight and automated feedback on this self-monitoring that recommended strategies for overcoming barriers and provided positive reinforcement for behavior change. Primary outcomes were weight loss at the end of the 12-week program and the proportion of participants losing at least 5% of their initial weight. Secondary outcomes were calories expended in physical activity, frequency of self-weighing, and adherence to other prescribed behavioral strategies.
