Low Intensity Weight Loss for Young Adults: Autonomous vs. Extrinsic Motivation

描述（由申请人提供）：40%的18-25奥尔兹超重或肥胖，但这一人群在标准行为减肥（BWL）计划中的代表性明显不足，迄今为止，还没有针对这一年龄组减肥的完全有效的试验。对这一年龄组进行的形成性工作表明，现有的BWL计划不能满足他们的独特需求，并确定缺乏动力是体重管理的根本障碍。这项建议的主要目的是测试两种新的，低强度的基于网络的减肥方法在这个年龄段的相对有效性，这些方法特别注重增强动机，相对于标准的基于网络的计划。我们最近对这两种方法进行了试点测试，取得了可喜的成果。这两个为期3个月的干预计划包括一个单一的小组为基础的会议，其次是一个基于网络的计划，每周的教训，自我监测平台和个性化的反馈。其中一个项目植根于自我决定理论，旨在通过在治疗项目中提供各种个人选择，强调围绕行为目标和每周反馈的自主性，促进内在动机和促进自主自我调节。另一种干预基于学习理论和行为经济学原理，并为满足自我监测目标提供小的经济激励;此外，实现临床显著体重减轻的参与者参加抽奖，以获得额外的经济激励。这两种方法的初步数据都非常有希望-参与和保留都很强，参与者在3个月时实现了临床显著的体重减轻（ITT=自主动机计划中的4.8%，外在动机计划中的8.8%）。此外，在没有任何额外接触的情况下，6个月时体重减轻保持不变（分别为5.1%和10.1%）。我们提出了一个3臂随机对照试验，以测试这些新的方法来减肥在这个高风险人群的长期疗效。受试者为381名18-25岁的年轻人，体重指数（BMI）为25-45 kg/m2，随机分为3组：1）标准Web BWL（Web），2）Web +自主动机（Web+Aut）或3）Web +外部动机（Web+Ext）。所有组将接受6个月的计划，随后是6个月的无接触随访期。将在第2周和第2、4和6个月评估动机。将在0、3、6和12个月时评估体重和次要结局。我们将在6个月时比较所有三个组的治疗效果，并比较6至12个月期间维持体重减轻的组。我们还将研究与我们的理论框架（即自主动机，外在动机）一致的治疗结果的介质。我们假设，与Web相比，Web+Aut和Web+Ext条件在6个月时将产生更大的体重减轻和次要结局的改善。我们进一步假设，与Web+Aut相比，Web+Ext将在6个月时实现更大的体重减轻和次要结局改善。

DESCRIPTION (provided by applicant): Forty percent of 18-25 year olds are overweight or obese, yet this population is also markedly under- represented in standard behavioral weight loss (BWL) programs and to date, no fully powered trials exist which target this age group for weight loss. Formative work conducted with this age group revealed that existing BWL programs do not meet their unique needs, and also identified lack of motivation as a fundamental barrier for weight management. The primary aim of this proposal is to test the relative efficacy of two novel, low intensity web-based approaches to weight loss in this age group that are specifically focused on enhancing motivation, relative to a standard web-based program. We recently pilot tested these two approaches with promising results. Both 3-month intervention programs consisted of a single group based session, followed by a web- based program with weekly lessons, a self-monitoring platform and personalized feedback. One program was rooted in Self-Determination Theory and designed to facilitate intrinsic motivation and promote autonomous self-regulation by offering a variety of personal choices in the treatment program and emphasizing autonomy around behavioral goals and in weekly feedback. The other intervention was grounded in learning theory and principles of behavioral economics, and offered small financial incentives for meeting self-monitoring goals; further, participants achieving a clinically significant weight loss were entered into a raffle for additionl monetary incentives. Preliminary data for both approaches are quite promising - engagement and retention were strong, and participants achieved clinically significant weight losses at 3 months (ITT=4.8% in the Autonomous Motivation program and 8.8% in the Extrinsic Motivation program). Moreover, weight losses were maintained at 6 months without any additional contact (5.1% and 10.1%, respectively). We propose a 3-arm randomized controlled trial to test the longer-term efficacy of these novel approaches to weight loss in this high risk population. Participants will be 381 young adults, 18-25 years, with a body mass index (BMI) of 25-45 kg/m2, who will be randomized to 1 of 3 arms: 1) Standard Web BWL (Web), 2) Web + Autonomous Motivation (Web+Aut), or 3) Web + Extrinsic Motivation (Web+Ext). All arms will receive a 6-month program followed by a 6-month no-contact follow-up period. Motivation will be assessed at week 2 and months 2, 4, and 6. Assessments of weight and secondary outcomes will occur at 0, 3, 6, and 12 months. We will compare treatment effects across all three arms at 6 months, and compare arms on weight loss maintenance from 6 to 12 months. We will also examine mediators of treatment outcomes consistent with our theoretical framework (i.e. autonomous motivation, extrinsic motivation). We hypothesize that the Web+Aut and the Web+Ext conditions will produce greater weight loss and improvement in secondary outcomes at 6 months, compared with Web. We further hypothesize that Web+Ext will achieve greater weight loss and improvement in secondary outcomes at 6 months, relative to Web+Aut.