Addictive mechanisms in obesity: Is there a unique contribution of food addiction compared to binge eating disorder?

肥胖是西方世界的主要健康问题之一。目前，德国约有18%的人口被诊断为肥胖，BMI≥30kg/m2。不幸的是，减肥干预的长期效果很低。提高疗效的一种方法可能是为肥胖患者的特殊亚群提供更有针对性的干预措施。这种干预措施的发展需要更好地了解导致肥胖的心理机制。在这方面，与肥胖相关的两种情况特别相关：暴食症（BED）和食物成瘾（FA）。BED是肥胖症中最常见的精神障碍，其特征是频繁、反复发作的暴饮暴食，在此期间，个体会主观地失去对饮食的控制。因此，吃东西最初似乎能缓解负面情绪，但结果是羞耻和痛苦。FA的概念是基于这样的假设，即某些美味的食物（即高盐、高脂肪和精制碳水化合物）可能会引发物质使用障碍（如渴望）的反应模式，但也会失去控制。在患有BED的肥胖患者中，观察到FA的患病率为57%，这表明这两种结构并不完全重叠。然而，目前在区分肥胖和FA以及肥胖和BED的潜在心理过程方面的研究相当缺乏。在此背景下，本研究的目的是调查BED和FA是否在导致肥胖的情感和认知心理过程中是两种不同但重叠的条件。采用混合方法受试者间设计，分为“肥胖+FA+BED”、“肥胖+FA”、“肥胖+BED”、“肥胖”四组，共360名受试者。BED和FA的诊断将基于icd -11标准，对于FA，物质使用障碍的标准将适用于食物；所有组将根据年龄和性别进行匹配（50%为女性）。所有参与者的纳入标准为BMI≥30 kg/m2，年龄≥18岁，≤65岁。这项研究将包括一次持续约3小时的单次测试，以及为期6个月的随访（以探索诊断的稳定性）。与食物相关的和中性刺激的实验任务将被执行和问卷调查，例如情绪调节的困难和从食物中获得满足和补偿的体验。我们预计，FA的诊断将与更严重的线索反应性、对食物更明显的方法偏见、延迟折扣方面的缺陷和食物带来的更高满足感有关，而BED将与情绪调节方面的更高缺陷和食物带来的更高补偿感有关。我们预计，与所有其他组相比，患有FA和BED的肥胖患者在食物相关抑制控制方面表现出最大的损害。

Obesity is one of the major health problems in the Western World. At present, about 18% of the German population are diagnosed as obese as indicated by a body mass index (BMI) ≥ 30kg/m2. Unfortunately, the long-term efficacy of weight loss interventions is low. One way to enhance the efficacy may be to provide more tailored interventions for special subgroups of patients with obesity. The development of such interventions requires a better understanding of the psychological mechanisms that contribute to obesity. In this regard, two conditions related to obesity are particularly relevant: binge eating disorder (BED) and food addiction (FA). BED is the most common mental disorder reported in obesity and is characterized by frequent, recurrent episodes of binge eating during which the individual experiences a subjective loss of control over eating. Eating thereby seems to provide initially a relief from negative feelings, but results in shame and distress. The FA concept is based on the assumption that certain palatable foods (i.e. high in salt, fat, and refined carbohydrates) may trigger response patterns known from substance use disorders like craving, but also loss of control. In obese patients with BED, prevalence rates of FA of 57% are observed, suggesting that the constructs do not entirely overlap. However, there is at present a considerable lack of research differentiating obesity and FA and obesity and BED regarding underlying psychological processes. Against this background, the aim of this study is to investigate whether BED and FA are two distinct, yet overlapping, conditions regarding affective and cognitive psychological processes contributing to obesity. A mixed-methods between-subjects design with four groups (“obesity+FA+BED”, “obesity+FA“, obesity+BED, “obesity”; total N=360 participants) will be implemented. Diagnosis of BED and FA will be based on ICD-11-criteria, in the case of FA the criteria of substance use disorders will be adapted for food; all groups will be matched regarding age and gender (50% female). For all participants, inclusion criteria are BMI ≥30 kg/m2, and age ≥18 and ≤65 years. The study will comprise a single test-session lasting about three hours as well as a sixth-months follow-up (to explore the stability of the diagnoses). Experimental tasks with food-related and neutral stimuli will be administered and questionnaires on, for example, difficulties of emotion regulation and experiences of gratification and compensation from food. We expect that a diagnosis of FA will be associated with more severe cue-reactivity, a more pronounced approach bias towards food, deficits regarding delay discounting and higher gratification from food, while we expect that BED will be associated with higher deficits of emotion regulation and higher feelings of compensation from food. We expect that obese patients with FA and BED will show the greatest impairment of food-related inhibitory control compared to all other groups.