高中生外貌導向社群媒體意識經體重高估對問題飲食行為的影響：自尊之調節式中介效果分析

Abstract

背景：問題飲食行為不僅是衍生成疾病的高風險前驅狀態，同時也與健康相關生活品質下降密切關聯。我國71.1%的國高中生對自己身型外觀感到不滿意，且57.8%的青少年認為自己該增重或減重才會達到心中完美的樣貌，社群媒體不只重塑大眾對身體意象的關注，人們也因經常接觸到理想化的照片以及社會比較的文化，進而產生越來越多的不滿足感、心理困擾以及問題飲食行為的風險。 目的：本研究欲探討青少年外貌導向社群媒體意識(ASMC)、體重高估、自尊和問題飲食行為之關係。具體研究問題為：（1）探討高中生ASMC、體重高估、自尊與問題飲食行為之相關性（2）檢驗ASMC對高中生問題飲食行為之直接預測力（3）探討體重高估在ASMC與問題飲食行為間的中介作用（4）檢驗自尊在ASMC影響問題飲食行為路徑中的調節效果。 方法：研究採次級資料分析，以新北市某高中786名學生為研究對象。首先以描述性統計了解樣本分布情形，接著使用廣義結構方程模型（Generalized Structural Equation Model, GSEM）來檢驗體重高估對ASMC與三種問題飲食行為的中介效果，最後再進一步討論自尊在ASMC與體重高估間，以及自尊在ASMC與問題飲食行為間是否具有調節效果。 結果：ASMC對三種問題飲食行為皆有顯著的直接預測能力。在中介機制上，僅「認知約束飲食」路徑獲得支持，意即ASMC不只直接與認知約束飲食有所相關，參與者體重高估的程度也較高，並同時控制飲食以避免增重。在加入調節變項後，自尊僅顯著調節了ASMC對情緒性飲食行為的直接路徑，惟三個模型的調節中介指數皆未達統計上的顯著，調節式中介模型皆不成立。 討論：研究發現體重高估在ASMC與認知約束飲食間扮演部分中介角色，意即媒體與社會壓力易使青少年產生錯誤的體重認知，進而引發節食與減食行為。然而，本研究的調節式中介模型皆並未成立，推測整體自尊可能不足以完全緩衝社群媒體外貌情境對問題飲食的負面影響。未來研究可進一步聚焦於社群媒體情境下，「外貌自尊」或其他的心理概念對不同飲食行為的具體作用機制。

Background: Problematic eating behaviors are not only high-risk precursors for developing diseases but are also closely associated with decreased health-related quality of life. In Taiwan, 71.1% of junior and senior high school students are dissatisfied with their body appearance, and 57.8% of adolescents believe they need to either gain or lose weight to achieve their ideal appearance. Social media has reshaped public attention toward body image; frequent exposure to idealized photos and a culture of social comparison have led to increasing dissatisfaction, psychological distress, and a heightened risk of problematic eating behaviors. Aims: This study aims to explore the relationships among adolescents’ appearance- related social media consciousness (ASMC), weight overestimation, self-esteem, and problematic eating behaviors. The specific research questions are: (1) To examine the correlations among ASMC, weight overestimation, self-esteem, and problematic eating behaviors in high school students. (2) To test the direct predictive power of ASMC on problematic eating behaviors among high school students. (3) To investigate the mediating role of weight overestimation in the relationship between ASMC and problematic eating behaviors. (4) To examine the moderating effect of self-esteem on the pathway through which ASMC influences problematic eating behaviors. Methods: This study uses secondary data analysis, with a sample of 786 students from a high school in New Taipei City. Descriptive statistics were first used to understand the sample distribution. Weight overestimation was then treated as a mediating variable to examine the effect of ASMC on disordered eating. Furthermore, the study explored whether self-esteem moderates the relationships between ASMC and weight overestimation, as well as between ASMC and problematic eating behaviors. Results: ASMC showed significant direct predictive power for all three types of problematic eating behaviors. Regarding the mediating mechanism, only the pathway of “cognitive restraint eating” was supported. This indicates that ASMC not only directly triggers cognitive restraint eating but also leads participants to develop cognitive bias in overestimating their weight, which in turn results in dieting behaviors. In terms of the moderated mediation model, self-esteem significantly moderated the direct pathway between ASMC and emotional eating behavior. In other words, individuals with higher self-esteem demonstrate greater emotional resilience when facing ASMC, thereby reducing the tendency to eat in response to negative emotions. Discussion: The findings indicate that weight overestimation partially mediates the relationship between ASMC and cognitive restraint in eating, suggesting that media and social pressures may lead adolescents to develop inaccurate perceptions of their body weight, which in turn may contribute to dieting and food-restriction behaviors. However, none of the moderated mediation models in the present study were supported. This may indicate that global self-esteem alone is insufficient to fully buffer the negative effects of social media–related appearance contexts on disordered eating. Future research could further investigate the specific mechanisms through which appearance-related self-esteem or other psychological constructs influence different types of eating behaviors in social media contexts.