Weight Suppression, Dieting and Bulimia Nervosa: A Biobehavioral Study

描述（申请人提供）：体重抑制，节食和神经性贪食：一项生物行为研究。神经性贪食症（BN）是一种使人衰弱的精神疾病，主要影响年轻女性。已经确定了经验支持的治疗BN的方法，但只有不到一半的治疗个体从这种疾病中获得长期缓解，可能是因为目前的治疗方法没有充分考虑到有助于维持这种疾病的变量。BN的社会心理模型强调节食是暴食和排便的近端原因。节食既有心理方面的，也有生物方面的，但现有的减肥模型绝大多数都集中在其心理影响上。我们区分了饮食引起的长期能量不平衡（体重抑制（WS），或一个人最高体重与当前体重之间的差异）和短期能量不平衡（当前节食以减轻体重或避免体重增加）。最近的研究表明，BN中的WS水平升高，WS的程度预测了BN各种特征的严重程度及其临床病程。对当前节食（CD）减肥的研究发现，它与BN中暴饮暴食的减少有关，这一发现与该疾病的主流模型相冲突。拟议的研究将检查BN患者WS和CD的生物学（如能量消耗、神经内分泌和食欲激素）和行为（如暴饮暴食和排便）相关性。（相对较少的患有BN的人报告节食是为了避免体重增加，但其生物学和行为相关性也将被检查。）该项目将招募132名女性（66名来自德雷塞尔大学，66名来自哥伦比亚大学），她们符合DSM-V的BN临时诊断标准。我们将检验以下假设：1)CD和升高的WS将与代谢和食欲的生物指标改变有关；2)WS将预测更大的暴食和排便，CD将预测更少的暴食，使用生态瞬时评估（EMA）测量；3)更高的每日食物限制意图实时评级将预测当天暴食的可能性降低，但在随后的几天暴食的可能性增加。所有参与者的评估将包括：体重和以前报告的最高体重（用于计算WS）、饮食失调检查、14天的EMA（用于评估食物限制意图）、暴饮暴食和排泻发作、3次24小时食物召回、静息能量消耗、代谢和食欲激素（包括完整的甲状腺检查、瘦素、胃促生长素、皮质醇和雌激素）。参与者将被要求在6个月后返回进行体重的后续评估。本研究将阐明两种常见但尚未探索的节食类型如何影响BN患者的生物学和行为变量，这可能导致对BN流行模型的修改和改善治疗结果的新策略。

DESCRIPTION (provided by applicant): Weight Suppression, Dieting and Bulimia Nervosa: A Biobehavioral Study. Bulimia nervosa (BN) is a debilitating psychiatric disorder that primarily affects young women. Empirically supported treatments for BN have been identified but less than half of treated individuals achieve long-term remission from the disorder, possibly because current treatment approaches do not sufficiently account for variables that help maintain the disorder. Psychosocial models of BN emphasize the role of dieting as a proximal cause of binge eating and purging. Dieting has both psychological and biological facets but existing models of BN have overwhelmingly focused on its psychological impact. We have differentiated between a diet-induced long-term energy imbalance (weight suppression (WS), or the difference between one's highest-ever body weight and current weight) and a short-term energy imbalance (current dieting to either lose weight or avoid weight gain). Recent research has shown that WS levels in BN are elevated and that degree of WS predicts the severity of various BN characteristics and its clinical course. Studies of current dieting (CD) to lose weight have found that it is associate with reduced binge eating in BN, a finding that conflicts with prevailing models of the disorder. The proposed research will examine biological (e.g., energy expenditure, neuroendocrine and appetitive hormones) and behavioral (e.g., binge eating and purging) correlates of WS and CD in those with BN. (Relatively few of those with BN report dieting to avoid weight gain but its biological and behavioral correlates will also be examined.) The project will recruit 132 women (66 at Drexel University and 66 at Columbia University) meeting provisional DSM-V diagnostic criteria for BN. We will test the hypotheses that 1) CD and elevated WS will be associated with alterations in biological indices of metabolism and appetite, 2) WS will predict greater binge eating and purging, and CD will predict less binge eating, measured using Ecological Momentary Assessment (EMA), and 3) higher real time ratings of daily food restriction intentions will predict a reduced probability of binge eating during the same day but an increased probability of binge eating in subsequent days. Assessments for all participants will include: weight and reported previous highest weight (to calculate WS), the Eating Disorders Examination, 14 days of EMA to assess food restriction intentions, binge eating and purging episodes, three 24-hr food recalls, and resting energy expenditure and metabolic and appetitive hormones (including complete thyroid panel, leptin, ghrelin, cortisol and estradiol). Participants will be asked to return 6 months later for follow-up assessments of weight. This study will elucidate how two common yet largely unexplored types of dieting influence biological and behavioral variables in patients with BN, which could lead to modifications of prevailing models of BN and new strategies for improving treatment outcome.