Body dissatisfaction (BD) includes negative thoughts and feelings about one’s body shape. Although typically assessed as a trait, BD has been found to fluctuate within a day. The present study examined whether daily instability in BD differs according to trait BD, eating disorder (ED) diagnosis, and engagement in maladaptive exercise. Participants with EDs ( = 166) and controls ( = 44) completed a self-report measure of trait BD and reported BD and engagement in maladaptive exercise five times daily for 14 days as part of an ecological momentary assessment protocol. BD instability was calculated as adjusted mean squared successive difference. On average across assessments, participants with EDs reported a 16% change in their BD ratings between consecutive assessments, which was significantly higher than the 12% change in controls. Trait BD was significantly inversely associated with BD instability in individuals with EDs, but not in controls. BD instability did not differ across ED diagnoses or between days with versus without maladaptive exercise. Findings suggest that BD is a dynamic state that varies within a day, especially in participants with EDs. Further research is needed to clarify whether this heightened instability in BD is a clinically relevant factor underlying ED symptoms.

中文翻译：

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有或没有饮食失调的个体每日身体不满意程度不稳定

身体不满意 (BD) 包括对自己体型的负面想法和感受。尽管通常将 BD 作为一种特征进行评估，但人们发现 BD 在一天内会发生波动。本研究检验了 BD 的日常不稳定性是否因 BD 特征、饮食失调 (ED) 诊断和参与适应不良运动而异。ED 参与者 (= 166) 和对照组 (= 44) 完成了对 BD 特征的自我报告测量，并报告了 BD 和参与适应不良运动，每天 5 次，持续 14 天，作为生态瞬时评估方案的一部分。BD 不稳定性计算为调整均方连续差。平均而言，患有 ED 的参与者报告称，在连续评估之间，他们的 BD 评分发生了 16% 的变化，明显高于对照组 12% 的变化。在患有 ED 的个体中，BD 特质与 BD 不稳定呈显着负相关，但在对照组中则不然。BD 不稳定性在不同 ED 诊断之间或有与没有适应不良运动的天数之间没有差异。研究结果表明，BD 是一种动态状态，一天之内就会发生变化，尤其是患有 ED 的参与者。需要进一步的研究来阐明 BD 的这种高度不稳定性是否是 ED 症状背后的临床相关因素。