An exploration of the relationship between gastric interoceptive sensibility, body image, and food choice.

身体形象(BI)，即我们如何感知和感受我们的身体外观(Cash&Deagle，1997)，由外部身体感知和内部感觉信号提供信息。感觉间感觉是对源自我们的内脏器官(心、肺、胃；Garfinkel等人，2015)的身体内部感觉的主观检测和评估，对于进食障碍(EDS)等BI障碍来说很重要。EDS的一个诊断标志是身体形象紊乱(美国心理协会，2013年)，尤其是神经性厌食症(AN)患者高估了他们的身体尺寸，并对他们的身体进行了负面评估(Hagman等人)。2015年)。与健康参与者相比，勃起功能障碍患者表现出内感敏感性差异(Jenkinson等人。关于饮食障碍清单(EDI；Garner，Olmsted，&Polivy，1983)和相互感知意识的多维评估(Maia；Mehling等人，2012)。然而，EDI和MAIA测量了整个身体的相互感觉敏感性，掩盖了特定身体系统对BI的贡献。胃间感觉敏感性(GIS)与BI特别相关，因为那些患有亚临床和临床ED的人被发现干扰了胃内感觉(van Dyck等人，2020)。通过水负荷-II问卷衡量的地理信息系统也与生物多样性指数相关(Todd等人，2020年)。但是，这份问卷并没有全面涵盖地理信息系统。这是因为它是使用小样本数据开发的，是一维的，侧重于对胃感觉的负面评估(例如，询问不适和内疚)，使其与饱腹感而不是饱足感相关，这是两种不同的感觉(van Dyck等，2016)。此外，这一量表还没有得到实证验证。因此，我们的目标是使用主题、解释因素、验证性因素和分层多元回归分析来开发一个地理信息系统量表。为了扩展先前的研究，表明地理信息系统和商业智能之间的相关性(Todd等人，2020)，新的量表将被用来调查地理信息系统和商业智能是否直接相互调节。在虚拟现实全身错觉中，地理标志和商业智能将分别通过装水和头像身体大小进行操纵。证明地理信息系统和BI之间的调节联系将使新的量表有助于识别患有ED风险的个人，考虑到这些患者的高死亡率和糟糕的健康结果，这是一个主要优势(field等人，2012；Mascolo，Trent，Colwell，&Mehler，2012；Smink，Van Hoeken&Hoek，2012)。此外，了解胃内感觉的独特作用将有助于更广泛的理论，即内感觉敏感性的多维性质及其对心理健康的影响。尽管有证据表明内感觉与身体形象之间存在关系，但探索两者在食物选择中的作用的研究有限。饥饿和饱腹感是胃系统产生的感觉，与食物选择有关(Benelam，2009；Tuorila等人，2001)。身体形象在食物选择中的作用还不是很清楚。Verhulst等人(2018)使用虚拟现实来操纵感知的身体大小，但发现这对食物选择没有影响。相反，Tambone等人。(2021)发现，化身为苗条的化身可以避免高卡路里食物。这些混合的发现可能是因为两项研究都没有对胃内感觉进行控制。因此，我们的目标是对地理信息系统和商业智能对食物选择的相对贡献进行计算建模。漂移扩散模型显示了地理信息系统和商业智能是如何影响食物选择的。了解这一点对于开发鼓励健康食品选择的工具至关重要。这可能是重要的一步，不仅对于AN等精神疾病，而且对于解决肥胖问题也是如此，肥胖症是西方世界日益关注的健康问题(世界卫生组织，2021年)。

Body image (BI), how we perceive and feel about our body's appearance (Cash & Deagle, 1997), is informed by external bodily perceptions and interoceptive signals. Interoceptive sensibility, the subjective detection and appraisal of internal bodily sensations originating from our visceral organs (heart, lungs, stomach; Garfinkel et al., 2015), is important for disorders of disturbed BI, like eating disorders (EDs). A diagnostic hallmark of EDs is a disturbed body image (American Psychological Association, 2013), as anorexia nervosa (AN) patients in particular overestimate their body size and negatively evaluate their body (Hagman et al. 2015). ED patients show interoceptive sensibility differences compared to healthy participants (Jenkinson et al. 2018) on The Eating Disorder Inventory (EDI; Garner, Olmsted, & Polivy, 1983) and Multidimensional Assessment of Interoceptive Awareness (MAIA; Mehling et al., 2012). However, the EDI and MAIA measure interoceptive sensibility across the whole body, masking the contribution of specific body systems to BI. Gastric interoceptive sensibility (GIS) is particularly relevant to BI as those with subclinical and clinical EDs are found to have disturbed gastric interoception (van Dyck et al., 2020). GIS, measured by the Water Loading-II questionnaire, also correlates with BI (Todd et al., 2020). However, this questionnaire does not comprehensively capture GIS. This is because it was developed using data from a small sample, is unidimensional, and focuses on the negative evaluation of gastric sensations (e.g. asking about discomfort and guilt), making it relevant to fullness rather than satiation, two distinct sensations (van Dyck et al., 2016). Furthermore, this scale has not been empirically validated. Therefore, we aim to develop a GIS scale using thematic, explanatory factor, confirmatory factor, and hierarchical multiple regression analyses.To extend previous research showing a correlation between GIS and BI (Todd et al., 2020), the new scale will be used to investigate if GIS and BI directly modulate each other. GIS and BI will be manipulated by water-loading and avatar body size in a virtual reality full-body illusion, respectively. Evidencing a modulatory link between GIS and BI would make the new scale useful for identifying individuals at an ED risk, a major advantage considering the high mortality rate and poor health outcomes of these patients (Field et al., 2012; Mascolo, Trent, Colwell, & Mehler, 2012; Smink, Van Hoeken & Hoek, 2012). Furthermore, understanding the unique role of gastric interoception will contribute to the wider theory of the multidimensional nature of interoceptive sensibility and its impact on mental health.Although there is evidence for a relationship between interoception and body image, there is limited research exploring the role of both in food choice. Hunger and satiety, sensations arising from the gastric system, have been linked to food choice (Benelam, 2009; Tuorila et al., 2001). The role of body image in food choices is less clear. Verhulst et al., (2018) used virtual reality to manipulate perceived body size, but found this to have no influence on food choices. Conversely, Tambone et al. (2021) found that embodying a slim avatar induced avoidance of high calorie food. These mixed findings may be because neither study controlled for gastric interoception. Therefore, we aim to computationally model the relative contributions of GIS and BI to food choices. Drift diffusion modelling shows how GIS and BI influence food choice. Understanding this is crucial for developing tools to encourage healthy food choices. This may be an important step, not just for psychiatric conditions such as AN, but also for tackling obesity, a growing health concern in the western world (World Health Organisation, 2021).