A Test of Nutritional Interventions to Enhance Weight Loss Maintenance

描述（由研究者提供）：肥胖是一种普遍的严重疾病。行为治疗（BT）已成为（非医学）治疗肥胖症的标准护理，产生医学上显著的体重减轻和心理社会功能的改善。然而，长期减肥仍然具有挑战性。肥胖的环境是一个因素，似乎使减肥维持难以实现。研究表明，改善BT长期结果的一种有希望的方法是更加重视改变食物的结构，成分和可用性。持续使用代餐（MR）是一种以前支持的方法，但没有这种方法的随机对照试验在减肥维持期间测试其有效性。其他有希望的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营养方法联合收割机组合成一种名为Nutritrol的治疗方法。将MR或Nutritrol干预整合到传统BT中可以减少或消除通常在BT之后的体重反弹。拟议研究的第一个目的是确定相对于标准BT条件，BT加MR或BT加Nutritrol是否会在治疗期间产生上级体重减轻，治疗后更好的体重减轻维持或心理社会结局的差异变化。第二个目的是确定在干预过程中，实验干预的具体目标实际上在预期方向上发生变化的程度，并评估这种变化是否可能导致体重减轻维持的改善。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MR或全面的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之一：1）BT，2）BT+MR，或3）BT+Nutritrol。治疗将在德雷克塞尔大学和宾夕法尼亚大学进行。每次治疗将持续1年，并将以小组形式进行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，将对受试者进行为期1年的随访。将在基线、6个月、12个月（即，治疗结束时）以及6个月和12个月随访时。主要结果变量包括体重、营养摄入和心理社会指标。

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.