Effectiveness Trial of a Dissonance-Based Obesity Prevention Program

描述(由申请人提供)：很少有肥胖预防计划在后续行动中降低体重增加的风险，而且那些计划非常密集(M持续时间=52小时)，使得传播困难和昂贵。一项简短的3小时选择性预防计划(健康体重)包括参与者驱动的健康饮食和体力活动、生活方式改变，通过3年的随访，相对于替代干预和仅评估对照，显着降低了BMI和肥胖症发病的增加。它以对身体不满意的年轻人为目标，因为这是肥胖的普遍风险因素，这些人被激励着改变健康的生活方式。为了提高疗效，我们从一个高效的基于不和谐的饮食失调预防计划中，增加了旨在诱导不健康饮食和活动习惯不和谐的活动。社会心理学实验表明，人们努力保持思想、语言和行为之间的一致性。因此，我们增加了口头、书面和行为练习，在这些练习中，年轻人讨论肥胖的成本、不健康的饮食和久坐行为、瘦的好处、健康的饮食和体育活动，以及导致肥胖的机构。参与这些活动可能会增加参与者寻求将他们的行动与会议中表达的观点相一致的可能性，从而产生更健康的未来生活方式选择。一项试点试验发现，与健康体重干预和教育手册情况相比，这一新的健康干预项目显著减少了从治疗前到治疗后BMI的增长(d分别为0.40和0.42)，与最有效的强化预防计划的效果规模相比，这一点是有利的。此外，其他肥胖预防计划的效果并没有显著优于可信的替代干预措施。我们建议进行一项严格的多点有效性试验，以测试在原本有效的健康体重干预措施中加入不和谐诱导因素是否可以改善体重增加的预防效果：300名因身体不满意而有可能出现未来不健康体重增加的大学生将被 随机分为8小时不和谐项目健康干预或8小时健康体重干预，在治疗前、治疗后、6个月、12个月和24个月完成体脂和其他结果的评估。目标1将测试项目健康是否减少相对于健康体重增加的体脂百分比；次要结果是抑郁和进食障碍症状。目标2将测试项目健康参与者是否报告了关于吃不健康食物和从事久坐行为的认知不协调，以及不协调的变化，以及报告的饮食摄入量和客观测量的活动水平，是否中介了干预对体脂百分比变化的影响。目标3将调查可能放大(预试身体不满意，偏爱一致性)或缓解(情绪性进食，物质使用)干预效果的潜在调节因素。我们将通过长期随访、主动控制条件以及直接测量身体成分和活动量来改进大多数肥胖预防试验。

DESCRIPTION (provided by applicant): Few obesity prevention programs have reduced risk for weight gain over follow-up and those that have are very intensive (M duration = 52 hrs.), making dissemination difficult and costly. A brief 3-hr selective prevention program (Healthy Weight) involving participant-driven healthy dietary and physical activity lifestyle changes significantly reduced increases in BMI and obesity onset relative to alternative interventions and assessment- only controls through 3-yr follow-up. It targets young adults with body dissatisfaction as this is a prevalent risk factor for obesity and such individuals are motivated t make healthy lifestyle changes. To enhance efficacy, we added activities designed to induce dissonance regarding unhealthy dietary and activity practices, drawing from a highly efficacious dissonance-based eating disorder prevention program. Social psychology experiments show that people strive to maintain consistency between thoughts, words, and actions. Thus, we added verbal, written, and behavioral exercises wherein youth discuss costs of obesity, an unhealthy diet, and sedentary behaviors, benefits of leanness, a healthy diet, and physical activity, and institutions that contribute to obesity. Engaging in these activities putatively increases the likelihood that participants will seek to align their actions with the perspectives expressed in the sessions, resulting in healthier future lifestyle choices. A pilot trial found tha this new Project Health intervention significantly reduced increases in BMI relative to both the Healthy Weight intervention and an educational brochure condition from pre to post (d = .40 and .42 respectively), comparing favorably to effect sizes from the most efficacious intensive prevention programs. Further, other obesity prevention programs have not significantly outperformed credible alternative interventions. We propose to conduct a rigorous multisite effectiveness trial that will test whether adding the dissonance-induction elements to the originally efficacious Healthy Weight intervention improves weight gain prevention effects: 300 college students at risk for future unhealthy weight gain by virtue of body dissatisfaction will be randomized to a refined 8-hr dissonance-based Project Health intervention or an 8-hr Healthy Weight intervention, completing assessments of body fat and other outcomes at pre, post, and 6, 12, and 24 month follow-ups. Aim 1 will test whether Project Health reduces increases in % body fat relative to Healthy Weight; secondary outcomes are depressive and eating disorder symptoms. Aim 2 will test whether Project Health participants report cognitive dissonance regarding eating unhealthy foods and engaging in sedentary behaviors and whether changes in dissonance, as well as reported dietary intake and objectively measured activity level, mediate the effects of the intervention on change in % body fat. Aim 3 will investigate potential moderators that may amplify (pretest body dissatisfaction, preference for consistency) or mitigate (emotional eating, substance use) intervention effects. We will improve upon most obesity prevention trials by using a long-term follow-up, an active control condition, and direct measures of body composition and activity.