بررسی یک مدل اجتماعی فرهنگی به تفصیل شرح داده از اختلال خوردن زنان دانشجو: نقش مقایسه اجتماعی و نظارت بدن

Abstract Social comparison (i.e., body, eating, exercise) and body surveillance were tested as mediators of the thin-ideal internalization-body dissatisfaction relationship in the context of an elaborated sociocultural model of disordered eating. Participants were 219 college women who completed two questionnaire sessions 3 months apart. The cross-sectional elaborated sociocultural model (i.e., including social comparison and body surveillance as mediators of the thin-ideal internalization-body dissatisfaction relation) provided a good fit to the data, and the total indirect effect from thin-ideal internalization to body dissatisfaction through the mediators was significant. Social comparison emerged as a significant specific mediator while body surveillance did not. The mediation model did not hold prospectively; however, social comparison accounted for unique variance in body dissatisfaction and disordered eating 3 months later. Results suggest that thin-ideal internalization may not be “automatically” associated with body dissatisfaction and that it may be especially important to target comparison in prevention and intervention efforts.

Introduction There is support for sociocultural models of disordered eating among college women (e.g., Dual Pathway Model – Stice, 1994 and Stice et al., 1996a; Tripartite Influence Model – Thompson, Heinberg, Altabe, & Tantleff-Dunn, 1999) – a group with high rates of diagnosable eating disorders, disordered eating, and body dissatisfaction in the USA and other Western countries (e.g., Berg et al., 2009, Eisenberg et al., 2011, Mikolajczyk et al., 2010, Said et al., 2013 and White et al., 2011). These sociocultural models tend to have several elements in common. According to them, disordered eating is partially a result of pressure for women to achieve the thin ideal (Striegel-Moore, Silberstein, & Rodin, 1986). In order for this pressure to have the most pronounced negative impact, it must be internalized. Indeed, if a woman internalizes this pressure/the thin ideal, it is likely that this thin-ideal internalization will have adverse effects (Thompson, van den Berg, Roehrig, Guarda, & Heinberg, 2004). It is of note though that among samples of college women, pressure for thinness accounts for unique variance in body dissatisfaction, even above and beyond the variance accounted for by thin-ideal internalization (e.g., Stice, Nemeroff, & Shaw, 1996). That is, on their own, repeated messages that one is not thin enough may increase dissatisfaction with the body (e.g., Stice, 2001). Thus, pressure for thinness may result in body dissatisfaction both directly and indirectly via its influence on thin-ideal internalization (e.g., Stice & Shaw, 2002). Both cross-sectional and prospective research studies have demonstrated that thin-ideal internalization is associated with body dissatisfaction (e.g., Keery et al., 2004, Shroff and Thompson, 2006 and Stice and Whitenton, 2002). Body dissatisfaction can in turn lead to disordered eating (Halliwell & Harvey, 2006). Yet, as highlighted by Fitzsimmons-Craft, Harney, et al. (2012), sociocultural models of disordered eating typically lack explanations as to how thin-ideal internalization leads to body dissatisfaction and subsequent disordered eating. In theory, women who have internalized the thin ideal would be at risk for developing body dissatisfaction when the ideal is not met, but how does a woman come to know that there is a discrepancy between what she would ideally like to look like and what she currently looks like? A better understanding of the mechanisms through which thin-ideal internalization is associated with body dissatisfaction would inform prevention and intervention efforts and provide researchers and clinicians with a more comprehensive understanding of the sociocultural influences underlying body dissatisfaction development. The current study focused on two prominent social psychological theories, namely social comparison (Festinger, 1954) and objectification (Fredrickson and Roberts, 1997 and McKinley and Hyde, 1996) theories, as explanations of the thin-ideal internalization-body dissatisfaction relation in the context of a sociocultural model among college women.

Results Descriptive and Preliminary Analyses We evaluated skewness and kurtosis for each measure (including the individual items of the OBCS Body Surveillance subscale) that was to be used in the SEM analyses at either T1 or both T1 and T2. We determined that no substantial violations existed (per Tabachnick & Fidell, 2012), and thus, no measures/items were transformed. Table 1 contains means and standard deviations for the study variables at T1, and Table 2 contains correlations among the study variables at T1. Correlations were in the directions expected based on the literature; that is, we found positive correlations between all measured variables, with the exception that BMI exhibited a significant negative correlation with the IBSS-R (r = −.18, p = .006). In SEM analyses, it is recommended that indicators of separate latent variables not be very highly correlated (i.e., rs should be less than .90; Tabachnick & Fidell, 2012). As can be seen in Table 2, many indicators of separate latent variables are related but the rs do not reach .90. This was also the case when we examined the correlations between the OBCS Body Surveillance subscale items, which were used as indicators of the body surveillance latent variable, and the other study constructs at T1, and when we examined correlations for the study variables/items at T2 that were used in SEM analyses. Table 1. Means and standard deviations of the measured variables at T1 (n = 226). Construct Measure M SD Possible range Pressure for thinness 1. Perceived Sociocultural Pressure Scale (PSPS) 2.48 0.75 1–5 2. Sociocultural Attitudes Toward Appearance Questionnaire-4 (SATAQ-4), Pressure 34.42 11.08 12–60 Thin-ideal internalization 3. Ideal-Body Stereotype Scale-Revised (IBSS-R) 3.78 0.53 1–5 4. SATAQ-4, Internalization 17.48 4.75 5–25 5. Beliefs About Attractiveness Scale-Revised (BAAR), Importance of Being Attractive and Thin 3.04 1.15 1–7 Social comparison 6. Body, Eating, and Exercise Comparison Orientation Scale (BEECOM), Body 31.26 7.20 6–42 7. BEECOM, Eating 28.26 7.43 6–42 8. BEECOM, Exercise 22.97 8.03 6–42 9. BEECOM, Total 82.51 20.48 18–126 Body surveillance 10. Objectified Body Consciousness Scale (OBCS), Surveillance 5.04 0.93 1–7 Body dissatisfaction 11. Body Shape Questionnaire (BSQ) 92.17 34.48 34–204 12. Eating Disorder Inventory-Body Dissatisfaction (EDI-BD) 31.94 10.22 9–54 13. Eating Disorder Examination-Questionnaire-6 (EDE-Q-6), Weight Concern/Shape Concern 2.67 1.53 0–6 Disordered eating 14. Bulimia Test-Revised (BULIT-R) 49.57 16.39 28–140 15. EDE-Q-6, Restraint 1.50 1.36 0–6 16. Eating Attitudes Test-26 (EAT-26) 9.24 7.30 0–78 Body mass index 17. Body mass index (BMI) 22.69 3.42 Actual range: 17.43–41.60 Table options Table 2. Correlations among the measured variables at T1 (n = 226). 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 1. PSPS – 2. SATAQ-4, Pressure .82*** – 3. IBSS-R .17* .26*** – 4. SATAQ-4, Internalization .40*** .49*** .42*** – 5. BAAR, Importance of Being Attractive and Thin .32*** .36*** .41*** .45*** – 6. BEECOM, Body .49*** .52*** .45*** .61*** .42*** – 7. BEECOM, Eating .44*** .50*** .38*** .56*** .42*** .73*** – 8. BEECOM, Exercise .39*** .43*** .41*** .52*** .43*** .69*** .69*** – 9. BEECOM, Total .50*** .55*** .47*** .63*** .48*** .90*** .90*** .89*** – 10. OBCS, Surveillance .28*** .30*** .34*** .52*** .39*** .65*** .47*** .47*** .60*** – 11. BSQ .61*** .66*** .28*** .57*** .46*** .70*** .65*** .62*** .74*** .54*** – 12. EDI-BD .56*** .61*** .20** .47*** .44*** .60*** .53*** .49*** .61*** .45*** .85*** – 13. EDE-Q-6, Weight Concern/Shape Concern .49*** .57*** .26*** .60*** .48*** .67*** .61*** .55*** .68*** .52*** .89*** .81*** – 14. BULIT-R .41*** .45*** .25*** .46*** .41*** .54*** .56*** .49*** .60*** .38*** .74*** .58*** .71*** – 15. EDE-Q-6, Restraint .30*** .36*** .18* .42*** .30*** .33*** .46*** .40*** .45*** .29*** .56*** .42*** .61*** .54*** – 16. EAT-26 .34*** .39*** .27*** .57*** .41*** .50*** .54*** .49*** .57*** .44*** .62*** .48*** .64*** .65*** .56*** – 17. BMI .32*** .40*** −.18** .02 .10 .20** .22** .18** .22** .09 .48*** .47*** .38*** .31*** .14* .14 – Note. PSPS = Perceived Sociocultural Pressure Scale. SATAQ-4 = Sociocultural Attitudes Toward Appearance Questionnaire-4. IBSS-R = Ideal-Body Stereotype Scale-Revised. BAAR = Beliefs About Attractiveness Scale-Revised. BEECOM = Body, Eating, and Exercise Comparison Orientation Scale. OBCS = Objectified Body Consciousness Scale. BSQ = Body Shape Questionnaire. EDI-BD = Eating Disorder Inventory-Body Dissatisfaction. EDE-Q-6 = Eating Disorder Examination-Questionnaire-6. BULIT-R = Bulimia Test-Revised. EAT-26 = Eating Attitudes Test-26. BMI = Body mass index. Variables are continuous, with higher values reflecting higher levels of the construct. * p < .05. ** p < .01. *** p < .001. Table options Structural Equation Modeling (SEM) Analyses More traditional sociocultural model of disordered eating. Following the recommendations of Tabachnick and Fidell (2012), we evaluated the adequacy of the more traditional sociocultural model of disordered eating measurement model before simultaneously evaluating both the measurement and structural components of the model. The SRMR (.042), CFI (.959), and TLI (.941) all approximated good fit for the more traditional sociocultural model measurement model according to the aforementioned criteria. However, the RMSEA value we obtained (.088; 90% confidence interval: .068–.108) indicated mediocre model fit (MacCallum, Browne, & Sugawara, 1996). Chen, Curran, Bollen, Kirby, and Paxton (2008) recommend that RMSEA values be evaluated in the context of other fit indices, rather than solely on strict cutoff values. On this basis, and considering that the other fit indices indicated good model fit, we concluded that the more traditional sociocultural model measurement model had an acceptable fit. Additionally, all measures loaded significantly onto their respective latent factors. This information suggests that these latent factors were adequately operationalized. Thus, this measurement model was used to test the more traditional sociocultural model of disordered eating structural model. Correlations between the latent variables were all positive and significant (rs of .54–.86, all ps < .001), and factor loadings are included in Fig. 2. Standardized path coefficients and factor loadings for a more traditional ... Fig. 2. Standardized path coefficients and factor loadings for a more traditional sociocultural model of disordered eating structural model. PSPS = Perceived Sociocultural Pressure Scale. SATAQ-4 = Sociocultural Attitudes Toward Appearance Questionnaire-4. IBSS-R = Ideal-Body Stereotype Scale-Revised. BAAR = Beliefs About Attractiveness Scale-Revised; we note that we are using the Importance of Being Attractive and Thin subscale. BSQ = Body Shape Questionnaire. EDI-BD = Eating Disorder Inventory-Body Dissatisfaction. EDE-Q-6 = Eating Disorder Examination-Questionnaire-6. BULIT-R = Bulimia Test-Revised. EAT-26 = Eating Attitudes Test-26. ***p < .001. Figure options Next, we evaluated the more traditional sociocultural model structural model. As with the measurement model, the structural model provided an acceptable fit to the data. The SRMR (.048), CFI (.951), and TLI (.933) all approximated good fit. However, the RMSEA (.093; 90% confidence interval: .074–.113) again indicated mediocre model fit (MacCallum et al., 1996). Considering that the other fit indices indicated good model fit, we concluded that the more traditional sociocultural model structural model had an acceptable fit. All model paths were positive and significant and are presented in Fig. 2. Results indicated that pressure for thinness accounted for 37.7% of the variance in thin-ideal internalization. Pressure for thinness and thin-ideal internalization accounted for 65.7% of the variance in body dissatisfaction. Lastly, body dissatisfaction accounted for 75.2% of the variance in disordered eating. Elaborated sociocultural model of disordered eating. We next examined an elaborated sociocultural model of disordered eating that incorporated social comparison and body surveillance as mediators of the thin-ideal internalization-body dissatisfaction relation. We again first tested the measurement model before analyzing the structural model. The RMSEA (.068; 90% confidence interval: .058–.078), SRMR (.054), CFI (.935), and TLI (.921) all approximated good fit according to the aforementioned criteria. Further, all measures/items loaded significantly onto their respective latent factors. This information suggests that the latent factors were adequately operationalized, and thus, this measurement model was used to examine the elaborated sociocultural model structural model. Correlations between the latent variables were all positive and significant (rs of .38–.86, all ps < .001), and factor loadings are included in Fig. 3. Standardized path coefficients and factor loadings for the elaborated ... Fig. 3. Standardized path coefficients and factor loadings for the elaborated sociocultural model of disordered eating structural model. PSPS = Perceived Sociocultural Pressure Scale. SATAQ-4 = Sociocultural Attitudes Toward Appearance Questionnaire-4. IBSS-R = Ideal-Body Stereotype Scale-Revised. BAAR = Beliefs About Attractiveness Scale-Revised; we note that we are using the Importance of Being Attractive and Thin subscale. BEECOM = Body, Eating, and Exercise Comparison Orientation Measure. OBCS = Objectified Body Consciousness Scale. BSQ = Body Shape Questionnaire. EDI-BD = Eating Disorder Inventory-Body Dissatisfaction. EDE-Q-6 = Eating Disorder Examination-Questionnaire-6. BULIT-R = Bulimia Test-Revised. EAT-26 = Eating Attitudes Test-26. **p < .01. ***p < .001. Figure options We then evaluated the structural model for the elaborated sociocultural model of disordered eating, which provided an acceptable fit to the data. The RMSEA (.070; 90% confidence interval: .060–.079), SRMR (.057), and TLI (.917) all approximated good fit. The CFI (.928) was slightly below the aforementioned criterion of .95; however, some work has indicated that CFI values greater than roughly .90 may indicate adequate fit (Kline, 2005). Additionally, given that other fit indices indicated good model fit, we concluded that the elaborated sociocultural model structural model had an acceptable fit. All model paths except for two were positive and significant; the non-significant paths were: the path from thin-ideal internalization to body dissatisfaction (β = .07, p = .703) and the path from body surveillance to body dissatisfaction (β = .11, p = .196). See Fig. 3 for the full structural model for the elaborated sociocultural model of disordered eating. Results indicated that pressure for thinness accounted for 40.4% of the variance in thin-ideal internalization. Thin-ideal internalization accounted for 77.3% of the variance in eating disorder-related social comparison and for 51.5% of the variance in body surveillance. Pressure for thinness, thin-ideal internalization, eating disorder-related social comparison, and body surveillance accounted for 72.0% of the variance in body dissatisfaction. Thus, by including social comparison and body surveillance in the model, an additional 6.3% of the variance in body dissatisfaction was explained. Finally, body dissatisfaction accounted for 75.2% of the variance in disordered eating. Given our interest in examining whether social comparison and body surveillance would mediate the thin-ideal internalization-body dissatisfaction relation in the context of the sociocultural model of disordered eating, it is notable that the path from thin-ideal internalization to body dissatisfaction was no longer significant once these constructs (i.e., social comparison, body surveillance) were included in the model. Indeed, results indicated that the total indirect effect of thin-ideal internalization on body dissatisfaction through social comparison and body surveillance (as a set) was significant, with a standardized point estimate of .47 (p < .001). Thus, social comparison and body surveillance significantly mediated the relation between thin-ideal internalization and body dissatisfaction in the context of this model. Given that the direct effect of thin-ideal internalization on body dissatisfaction in this model was not significant (β = .07, p = .703), this suggests indirect-only mediation ( Zhao, Lynch, & Chen, 2010), which is also known as “full mediation” ( Baron & Kenny, 1986). The specific indirect effects of each mediator showed that social comparison was a unique and significant mediator, with a standardized point estimate of .39 (p = .003). However, body surveillance was not a significant specific mediator of the thin-ideal internalization-body dissatisfaction relation, with a standardized point estimate of .08 (p = .198). A contrast confirmed that the indirect effect of social comparison in the thin-ideal internalization-body dissatisfaction relation was significantly stronger (p = .001) than the indirect effect of body surveillance. Prospective examination of social comparison and body surveillance as mediators of the thin-ideal internalization-body dissatisfaction link. Given that the elaborated sociocultural model of disordered eating provided a good fit to the data and the fact that social comparison and body surveillance (as a set) were found to significantly mediate the thin-ideal internalization-body dissatisfaction relation in the context of this cross-sectional model, we were interested in investigating whether this mediation model would hold when investigating it using half-longitudinal techniques (i.e., using the paths in the regression of the T2 mediators onto T1 thin-ideal internalization controlling for T1 mediator values and the paths in the regression of T2 body dissatisfaction onto the T1 mediators controlling for T1 levels of body dissatisfaction to estimate the specific indirect effects). However, before examining whether social comparison and body surveillance mediated the relation between thin-ideal internalization and body dissatisfaction half-longitudinally, it was necessary to examine whether these constructs prospectively predicted one another and if they prospectively predicted one another when controlling for baseline levels of the outcome variable. A single analysis using latent variables (using the same indicators as shown in Fig. 3 but at T2 in the case of social comparison and body surveillance) was conducted to assess the relationships between the thin-ideal internalization at T1 and social comparison and body surveillance at T2. Results indicated that thin-ideal internalization at T1 predicted significant variance in both social comparison (β = .65, p < .001; R2 = .43) and body surveillance (β = .54, p < .001; R2 = .29) at T2. However, this model did not provide a good fit to the data (RMSEA: .131; SRMR: .076; CFI: .832; TLI: .789), and thus, it was unclear whether these parameter estimates could be meaningfully interpreted. Next, a single analysis using latent variables (using the indicators shown in Fig. 3 but at T2 in the case of body dissatisfaction) was conducted to assess the relationships between social comparison and body surveillance at T1 and body dissatisfaction at T2. Results indicated that T1 social comparison predicted unique variance in T2 body dissatisfaction (β = .67, p < .001), while body surveillance did not (β = .01, p = .957). This model explained 45.2% of the variance in T2 body dissatisfaction and provided a modest fit to the data (RMSEA: .086; SRMR: .056; CFI: .929; TLI: .911). We then investigated whether these constructs prospectively predicted one another when controlling for baseline levels of the dependent variable. Examining these effects in a single model with latent variables, results indicated that thin-ideal internalization at T1 did not predict T2 social comparison (β = .01, p = .936) or body surveillance (β = −.01, p = .952) after controlling for baseline levels of these constructs. Additionally, this model did not provide a good fit to the data (RMSEA: .102; SRMR: .069; CFI: .814; TLI: .788). Likewise, social comparison and body surveillance at T1 did not predict body dissatisfaction at T2 after controlling for baseline levels (β = .03, p = .781; β = −.07, p = .361, respectively). This model provided a possibly acceptable fit to the data (RMSEA: .100; SRMR: .055; CFI: .911; TLI: .891). Given that these constructs were not found to predict change in one another over the course of 3 months, it was not possible that social comparison and body surveillance would mediate the thin-ideal internalization-body dissatisfaction relation prospectively. Thus, a half-longitudinal mediation model was not investigated. Examination of the prospective relations between social comparison/body surveillance and disordered eating. Finally, we investigated the relations between social comparison and body surveillance at T1 and disordered eating at T2 both without and with controlling for baseline levels of disordered eating. A single analysis using latent variables was conducted to assess the relationships between social comparison and body surveillance at T1 and disordered eating at T2. Results indicated that T1 social comparison predicted unique variance in T2 disordered eating (β = .74, p < .001), while body surveillance did not (β = −.12, p = .328). This model explained 43.3% of the variance in T2 disordered eating and provided a modest fit to the data (RMSEA: .086; SRMR: .060; CFI: .912; TLI: .890). A separate analysis revealed that social comparison and body surveillance at T1 did not predict disordered eating at T2 after controlling for baseline levels of disordered eating (β = −.08, p = .577; β = −.14, p = .143, respectively). This model did not provide a good fit to the data (RMSEA: .101; SRMR: .062; CFI: .871; TLI: .842).