مشکل دوگانه برای آسیب شناسی تغذیه ای؟ یک مطالعه تجربی در مورد نقش ترکیبی کمال گرایی و نارضایتی بدن

Background and objectives A number of correlational studies suggest that the combined presence of perfectionism and body dissatisfaction creates elevated risk for the development of eating disorder pathology. The aim of this study was to examine the causal role of this combination of risk factors for eating pathology. Method We conducted an experimental study in a sample of female college students (N = 47). Specifically, we performed an experimental manipulation of perfectionism and examined whether this manipulation would interact with body dissatisfaction to predict eating disorder symptoms. Results We found that the effect of the experimental manipulation was moderated by body dissatisfaction, such that women in the perfectionism condition and scoring high on body dissatisfaction exhibited the highest levels of eating disorder symptoms. Limitations The sample was rather small (resulting in limited statistical power) and the participants were predominantly healthy and well-adjusted women, which may limit the generalizability and interpretation of our findings. Conclusions The results suggest that the combination of perfectionism and body dissatisfaction is particularly detrimental and predictive of risk for eating disorder symptoms.

Research has shown that perfectionism has a robust association with eating disorder pathology (Bardone-Cone et al., 2007, Boone et al., 2011 and Bulik et al., 2003), with Evaluative Concerns (EC) perfectionism (i.e., being self-critical and being overly concerned with failure) yielding more pronounced associations than Personal Standards (PS) perfectionism (i.e., setting high personal standards). However, research also suggests that both components of perfectionism are associated not only with eating disorder pathology. Indeed, perfectionism has been found to affect a diversity of problems in various domains of life, such as the domains of education, sports, and work. For instance, perfectionism has been related to academic (Zhang, Gan, & Cham, 2007), work-related (D'Souza, Egan, & Rees, 2011), and athletic (Appleton, Hall, & Hill, 2009) burn-out. Further, perfectionism is a transdiagnostic vulnerability factor that has been shown to be highly prevalent in a variety of types of psychopathology, including not only eating disorders but also depression (Egan, Wade, & Shafran, 2011), anxiety (Shafran & Mansell, 2001), and chronic fatigue syndrome (Kempke et al., 2011). Although evidently there is a certain degree of comorbidity between eating disorder pathology and dysfunction in other life domains and other types of psychopathology, the breadth of maladaptive outcomes associated with perfectionism suggests that perfectionism may manifest in eating disorder symptoms only for some people. This is basically a question about the multifinality of risk factors for psychopathology (Nolen-Hoeksema & Watkins, 2011): why does perfectionism lead to eating pathology in some people while it may lead to other types of psychopathology in other people? In this study, we aimed to examine the moderating role of body dissatisfaction in this relation, thereby using an experimental study design. We hypothesized that young adult women with high levels of perfectionism who already experience difficulties to accept their own body will be particularly at risk for the development of a diverse range of eating disorder symptoms. 1.1. Multidimensional perfectionism and eating disorder symptoms Perfectionism is a rich and multidimensional construct referring to the tendency to set very high standards for achievement to oneself as well as the tendency to be self-critical and to engage in negative self-evaluation after failure (Hamachek, 1978). In the past few decades, a number of different multidimensional models of perfectionism have been developed, the most important ones being the models developed by Frost, Marten, Lahart, and Rosenblate (1990) and by Hewitt and Flett (1991). Central to each of these models is the notion that perfectionism entails the setting of high personal standards. Apart from this dimension of perfectionism, which often has been referred to as Personal Standards (PS) perfectionism, several scholars have emphasized that perfectionism also entails a tendency to be highly self-critical and to engage in negative self-evaluation, which has been referred as Evaluative Concerns (EC) perfectionism (e.g., Frost et al., 1993 and Frost et al., 1990). There is a rich clinical tradition identifying perfectionism as a critical vulnerability factor for eating disorder pathology (Bardone-Cone et al., 2007). In many cases, eating disorder patients' excessive attempts to regulate their food intake and body weight would represent a defensive coping mechanism to deal with the insecurity and need for control stemming from a perfectionist personality orientation (Shafran, Cooper, & Fairburn, 2002). Systematic empirical research has indeed confirmed associations between perfectionism and eating disorder pathology (see Egan et al., 2011 and Shafran et al., 2002 for reviews). Both PS perfectionism and EC perfectionism have been found to be related to eating disorder symptoms in both non-clinical (e.g., DiBartolo, Li, & Frost, 2008) and clinical populations (see Bardone-Cone et al., 2007 for a review), although associations between PS perfectionism and eating pathology are typically somewhat less pronounced than associations between EC perfectionism and eating pathology (Bardone-Cone et al., 2007 and Boone et al., 2010). The somewhat inconsistent association between PS perfectionism and ED pathology is also found in longitudinal studies. Whereas some longitudinal studies confirmed that PS perfectionism is related to increases in ED symptomatology across time (e.g., Boone et al., 2011), other studies did not yield evidence for such predictive effects (Gustafsson, Edlund, Kjellin, & Norring, 2009). These relatively inconsistent findings suggest that the relation between PS perfectionism and eating pathology in particular may be moderated by other vulnerability factors (such as body dissatisfaction). Additional evidence for the role of PS perfectionism as a (causal) risk factor for ED symptoms was obtained in a recent series of experimental studies (Boone et al., 2012 and Shafran et al., 2006). In these studies, participants were randomly assigned to a perfectionistic condition, in which participants were asked to set high personal standards during 24 h, or to a non-perfectionistic condition, in which participants were asked not to strive to meet high expectations. These studies found that at the end of the day participants in the perfectionistic condition reported significantly more anorectic symptoms (e.g., eating less caloric food, more restrained eating, and more regret after eating) and bulimic symptoms (e.g., overeating, feelings of loss of control) compared to those in the non-perfectionistic condition (Boone et al., 2012 and Shafran et al., 2006). Although these findings suggest that PS perfectionism represents a causal risk factor for both restrictive and bulimic symptomatology, it should be mentioned that effect-sizes were relatively small and that the experimental effect was not found on all of the hypothesized ED symptoms. As such, these experimental findings call for an examination of the combined and interactive role of another risk factor for eating pathology. Therefore, in this study, we aim to examine whether the effect of PS perfectionism on eating disorder outcomes is conditional upon the presence of an already existing proneness to body dissatisfaction. 1.2. Body dissatisfaction, eating disorder pathology, and the interaction with perfectionism Body dissatisfaction, which refers to a negative subjective evaluation of one's physical body, is said to be highly prevalent among adolescent girls and young adult women and has been shown to be associated quite strongly with eating disorder symptoms (Stice & Shaw, 2002). Body dissatisfaction has been shown to predict future levels of both restrained eating and bulimic symptoms (Allen et al., 2012, Johnson and Wardle, 2005 and Stice and Agras, 1998). Importantly, body dissatisfaction has also been found to be associated with over-evaluation of weight and shape (i.e. the extent to which a person judges its self-worth in terms of weight and shape), which is considered to be the core psychopathological feature of eating disorders (Wilksch & Wade, 2009). Given that body dissatisfaction has a strong and robust association with ED symptoms, it was deemed a likely candidate to serve as a factor explaining when perfectionism becomes associated with ED symptomatology. We hypothesized that the combination of PS perfectionism and body dissatisfaction is particularly likely to translate into ED symptoms for at least two reasons. First, when people with high personal standards are dissatisfied with their body, they might develop an unhealthy preoccupation with the perceived flaws of their body. According to Shafran et al. (2002), people with high standards are indeed likely to be hypervigilant to shortcomings. Because they perceive their body to be flawed, their body would start to take a central position in their experience and they would become more likely to invest their self-worth in this highly relevant and central domain (Shafran et al., 2002). As a result, they would only be satisfied with themselves when they are able to control their body and when they meet their own criteria for weight. In contrast, they would engage in harsh self-criticism when they fail to meet their self-imposed criteria (Shafran et al., 2002). This dysfunctional scheme of self-evaluation, where self-worth has become contingent upon the attainment of criteria for body weight and shape, is considered to be the core psychopathology of EDs (Fairburn, 2008). Second, when people with high levels of PS perfectionism invest in a particular life domain, they are likely do so in a rigid fashion (Shafran et al., 2002). That is, to gain control over their life they may develop an excessive urge to control body weight and shape and they may apply rigid standards to the domain of eating. As a consequence, individuals with high levels of body dissatisfaction and perfectionism might be vulnerable to engage in rigid dieting (Verstuyf, Patrick, Vansteenkiste, & Teixeira, 2012). Research has shown that rigid dieting often results in the opposite of what dieters aspire, that is, a temporary loss of control under the form of binge eating episodes (Howard & Porzelius, 1999). On the basis of this reasoning, we expected that the combined presence of perfectionism and body dissatisfaction may not only result in heightened drive for thinness and over-evaluation of weight and shape but also in binge eating symptoms. The interactive effects of perfectionism and body dissatisfaction are also represented in the three-factor interactive model of Vohs and colleagues (e.g., Vohs et al., 2001). They argued and found that the joint presence of high levels of perfectionism and body dissatisfaction were associated with bulimic symptomatology in people with low self-esteem. However, further support for this model has been rather inconsistent and limited to its effect on bulimic symptoms. Whereas Steele, Corsini, and Wade (2007) found that the predictive effect of the interaction between PS perfectionism and body dissatisfaction was strongest for women with high self-esteem (while the model predicted that the interaction would be strongest among women with low self-esteem), Watson, Steele, Bergin, Fursland, and Wade (2011) could not replicate the three-way interactive effect at all. Besides studies testing the three-factor interactive model of Vohs and colleagues, a number of previous cross-sectional (Welch, Miller, Ghaderi, & Vaillancourt, 2009) and longitudinal (Boone, Soenens, & Luyten, 2014) studies have provided some evidence for the interactive effect of perfectionism and body dissatisfaction in predicting (increases in) ED symptoms. However, these studies used a correlational design and were limited in their possibility to draw conclusions about the causal role of perfectionism in particular. 1.3. The present study To overcome the limitations of previous correlational research, the aim of the present study was to investigate the interactive effect of perfectionism and body dissatisfaction on a broad range of eating disorder symptoms using an experimental design, based on the procedure developed by Shafran et al. (2006). We aimed to examine whether the effect of experimentally manipulated perfectionism on the eating disorder symptoms would be most pronounced (or only significant) among participants with initially high levels of body dissatisfaction. To provide a conservative test of our hypotheses, we also measured participants' trait levels of PS perfectionism and EC perfectionism prior to the experimental manipulation and we controlled for these trait levels of perfectionism when examining the effect of the experimental manipulation.