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

身体意象（BI），我们如何感知和感受我们的身体的外观（Cash & Deagle，1997），是由外部身体感知和内感受信号告知的。内感受性，对源自我们的内脏器官（心脏、肺、胃; Garfinkel等人，2015），对于BI紊乱的疾病，如进食障碍（ED）很重要。ED的诊断标志是身体意象紊乱（美国心理学会，2013），因为神经性厌食症（AN）患者尤其高估了自己的体型，并对自己的身体进行了负面评价（Hagman等人，2015）。与健康参与者相比，艾德患者在进食障碍量表（EDI; Garner，Olmsted，& Polivy，1983）和内感受意识的多维评估（马亚; Mehling et al.，2012年）。然而，EDI和马亚测量整个身体的内感受性敏感性，掩盖了特定身体系统对BI的贡献。胃内感受性（GIS）与BI特别相关，因为发现具有亚临床和临床ED的那些人具有紊乱的胃内感受（货车Dyck等人，2020年）。通过水负荷-II问卷测量的GIS也与BI相关（托德等人，2020年）。然而，这份调查表并没有全面反映地理信息系统。这是因为它是使用来自小样本的数据开发的，是一维的，并且专注于胃感觉的负面评价（例如询问不适和内疚），使其与饱腹感而不是饱食感相关，这是两种不同的感觉（货车Dyck等人，2016）。此外，这一尺度尚未得到实证验证。因此，我们的目标是开发一个GIS规模使用专题，解释性因素，验证性因素，和分层多元回归分析。为了扩展以前的研究表明GIS和BI之间的相关性（托德等人，2020年），新的尺度将用于调查GIS和BI是否直接相互调节。GIS和BI将分别通过虚拟现实全身错觉中的水负载和化身身体大小来操纵。证明GIS和BI之间的调节联系将使新量表可用于识别处于艾德风险的个体，考虑到这些患者的高死亡率和不良健康结果，这是一个主要优势（Field等人，2012; Mascolo，Trent，科尔韦尔，& Mehler，2012; Smink，货车Hoeken & Hoek，2012）.此外，了解胃内感受的独特作用将有助于更广泛的内感受性的多维性及其对心理健康的影响的理论。虽然有证据表明内感受和身体形象之间的关系，有有限的研究探索两者在食物选择中的作用。饥饿和饱腹感，由胃系统产生的感觉，与食物选择有关（Benelam，2009; Tuorila等人，2001年）。身体形象在食物选择中的作用还不太清楚。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，化身苗条的化身会导致避免高热量食物。这些混合的结果可能是因为两项研究都没有控制胃内感受。因此，我们的目标是计算模型的GIS和BI的食物选择的相对贡献。漂移扩散模型显示了GIS和BI如何影响食物选择。了解这一点对于开发鼓励健康食物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，这是西方世界日益增长的健康问题（世界卫生组织，2021）。

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).