A Test of Nutritional Interventions to Enhance Weight Loss Maintenance

描述（由研究者提供）：肥胖是一种普遍且严重的疾病。行为治疗（BT）已成为肥胖（非医学）治疗的标准护理方法，既能在医学上显著减轻体重，又能改善心理社会功能。然而，长期减肥维持仍然具有挑战性。致肥环境似乎是使减肥难以维持的一个因素。研究表明，改善BT长期效果的一个有希望的方法是更加重视改变食物的结构、成分和可获得性。持续使用代餐（mr）是一种先前支持的方法，但没有随机对照试验测试这种方法在减肥维持期间的有效性。其他有希望改善减肥维持的营养方法包括降低食物能量密度和种类，增加食物结构和蛋白质摄入量，以及改变个人的个人食物环境。我们建议将这些其他的营养方法结合起来，形成一种叫做Nutritrol的治疗方法。将MRs或Nutritrol干预纳入传统BT可以减少或消除BT后通常出现的体重反弹。本研究的第一个目的是确定，相对于标准BT， BT + MR或BT + Nutritrol在治疗期间是否会产生更好的体重减轻，治疗后是否能更好地维持体重减轻，或在心理社会结果方面产生不同的变化。第二个目的是确定实验干预的具体目标在干预期间在预期方向上的实际变化程度，并评估这种变化是否可以解释减肥维持的改善。这项研究很重要，因为它可以提供第一个证据，证明目前的肥胖生活方式治疗标准可以通过添加MRs或全面营养改变计划来改善。研究设计要求将超重个体随机分配到三种治疗条件中的一种：1)BT, 2) BT+MR，或3)BT+Nutritrol。治疗将在德雷塞尔大学和宾夕法尼亚大学进行。每次治疗将持续1年，以小组形式进行75分钟的治疗。治疗将在第1-6个月每周进行一次，在第7-12个月每两周进行一次。治疗结束后，参与者将被随访1年。评估将在基线、6个月、12个月（即治疗结束）以及6个月和12个月的随访时完成。主要结果变量包括体重、营养摄入和社会心理测量。公共卫生相关性：肥胖正达到流行病的程度，并对健康造成严重后果。肥胖的标准行为治疗有效地促进了体重减轻，但长期维持体重减轻仍然具有挑战性。这项研究的主要目的是测试两种营养方案，当与标准行为治疗相结合时，可能会改善减肥的维持。

DESCRIPTION (provided by investigator): Obesity is a prevalent and serious medical condition. Behavioral treatment (BT) has become the standard of care for the (nonmedical) treatment of obesity, yielding both medically significant weight reductions and improvements in psychosocial functioning. However, long-term weight loss maintenance remains challenging. The obesogenic environment is one factor that appears to make weight loss maintenance difficult to achieve. Research suggests that a promising approach to improving the long-term results of BT is to place greater emphasis on modifying the structure, composition, and availability of food. Ongoing use of meal replacements (MRs) is one previously-supported way of doing so, but no randomized, controlled trial of this approach has tested its effectiveness during weight loss maintenance. Other promising nutritional methods for improving weight loss maintenance include decreasing food energy density and variety, increasing food structure and protein intake, and modifying individuals' personal food environments. We propose to combine these other nutritional methods into a treatment called Nutritrol. Integrating either MRs or the Nutritrol intervention into traditional BT could reduce or eliminate the weight regain that typically follows BT. The first aim of the proposed study is to determine if, relative to a standard BT condition, BT plus MR or BT plus Nutritrol will produce superior weight loss during treatment, better weight loss maintenance after treatment, or differential change in psychosocial outcomes. A second aim is to determine the degree to which the specific targets of the experimental interventions do in fact change in the anticipated direction during the intervention and to evaluate whether such changes might account for improvements in weight loss maintenance. This study is important because it could provide the first evidence that the current standard of care for obesity lifestyle treatment could be improved by the addition of MRs or a program of comprehensive nutritional change. The study design calls for randomly assigning overweight individuals to one of three treatment conditions: 1) BT, 2) BT+MR, or 3) BT+Nutritrol. Treatment will be carried out at Drexel University and the University of Pennsylvania. Each treatment will last 1 year and will be delivered through 75-minute sessions in a small group format. Treatment will be conducted on a weekly basis for months 1-6 and a bi-weekly basis for months 7-12. Following termination of treatment, participants will be followed for 1 year. Assessments will be completed at baseline, 6 months, 12 months (i.e., end of treatment), and at 6- and 12- month follow-ups. Major outcome variables will include body weight, nutritional intake, and psychosocial measures. PUBLIC HEALTH RELEVANCE: Obesity is reaching epidemic proportions and has serious health consequences. Standard behavioral treatment for obesity effectively promotes weight loss, but long-term maintenance of weight loss remains challenging. The primary aim of this study is to test two nutritional programs that, when combined with standard behavioral treatment, might improve weight loss maintenance.