ساختار عاملی و ارتباط بالینی پرسشنامه سرکوب افکار غذایی در زنان چاق مبتلا به اختلال پرخوری افراطی در جستجوی درمان

Prior research on the relations among eating behaviors and thought suppression is limited to a measure of general thought suppression, the White Bear Suppression Inventory. To address this limitation, researchers recently validated the Food Thought Suppression Inventory (FTSI). Analyses using this measure suggest that food thought suppression is distinct from and is more predictive of eating disorder psychopathology than is general thought suppression. The FTSI, however, has not yet been validated in clinical samples. The purpose of the current study is to examine the factor structure and clinical correlates of the FTSI within treatment seeking obese women with binge eating disorder (BED; N = 128). Analyses revealed a valid and reliable one-factor measure of food thought suppression that was related to higher levels of eating and general psychopathology. The findings provide evidence for the use of the FTSI with obese women with BED. Future research should examine the psychometric properties of the FTSI within larger and more diverse samples.

The Ironic Processes Theory suggests that thought suppression, or purposely trying to avoid certain thoughts, may have unwanted consequences such as increases in priming of the target thoughts (hyperaccessibility; Wegner & Erber, 1992), increases in target thoughts immediately once an individual tries to suppress specific thoughts, and increases in target thoughts following cessation of suppression attempts (the rebound effect; Wegner, 1994 and Wegner and Erber, 1992). Rumination may, therefore, be a likely outcome of thought suppression attempts. Research indicates general thought suppression is related to higher levels of psychiatric symptoms, such as depression (Wenzlaff & Wegner, 2000). Thought suppression also has been investigated in the context of specific themes, including food and eating-related constructs. The little existing research examining the association between thought suppression and eating behaviors has resulted in mixed findings. The consequences of thought suppression, such as hyperaccessibility and rebound, have been found to result from attempting to suppress food-related thoughts in some studies (Dejonckheere et al., 2003, Smart and Wegner, 1999, Soetens and Braet, 2006, Soetens et al., 2006 and Soetens, Braet and Moen, 2008) but not all (May et al., 2010, Soetens and Braet, 2007 and Soetens, Braet and Bosmans, 2008). Of note is that May et al. (2010) did not consider dieting status or weight in their analyses, both of which may influence thought suppression (e.g., Erskine and Georgiou, 2010, Kemps et al., 2008, O'Connell et al., 2005, Pop et al., 2004 and Soetens et al., 2006). Initial studies of thought suppression and eating behaviors (e.g. Soetens et al., 2006) were limited to the White Bear Suppression Inventory (WBSI), a self-report measure of general thought suppression. To address the limitation that eating-related studies were restricted to a general measure of thought suppression, rather than one specific to eating, researchers recently created the Food Thought Suppression Inventory (FTSI), which was validated with non-clinical samples of women ( Barnes, Fisak, & Tantleff-Dunn, 2010) and men ( Barnes & White, 2010). The items are based on the WBSI, for example: “There are things I prefer not to think about” from the WBSI was changed to “There are foods I prefer not to think about” for the FTSI. The measure includes a single, reliable, and valid factor of food thought suppression, and higher scores on the FTSI have been shown to be associated with higher BMI ( Barnes and White, 2010 and Barnes et al., 2010). The FTSI is moderately related to the WBSI and more strongly associated with important eating-related constructs than is the WBSI ( Barnes and White, 2010 and Barnes et al., 2010), suggesting that food thought suppression is distinct from, albeit related to, general thought suppression. Psychometric evaluations of the FTSI, however, have been limited to non-clinical samples. Existing research indicates that food thought suppression may evidence even greater clinical significance for obese persons with disordered eating such as those with binge eating disorder (BED; i.e., feeling loss of control while eating unusually large quantities of food without inappropriate compensatory behaviors). While Ward, Bulik, and Johnston (1996) posited a relationship between binge eating and thought suppression over 15 years ago, their theory only recently received empirical attention in non-clinical (Barnes and Tantleff-Dunn, 2010 and Barnes and White, 2010) and clinical samples (Barnes, Masheb, & Grilo, 2011). The latter study, which compared matched samples of obese persons with versus without BED, reported significantly higher levels of food thought suppression in the BED group (Barnes, Masheb & Grilo, 2011). Barnes, Masheb and Grilo (2011) also reported a positive association between food thought suppression and binge eating frequency among women with BED, a finding that was previously reported in a non-clinical sample of women (Barnes & Tantleff-Dunn, 2010). Unexpectedly, a negative correlation was observed between food thought suppression and binge eating frequency among men with BED, a finding that conflicts with previous reports with male non-clinical samples (Barnes and Tantleff-Dunn, 2010 and Barnes and White, 2010). In summary, preliminary data suggest there may be an association between food thought suppression and various aspects of disordered eating patterns and this relationship may differ between obese individuals with versus without BED. Further investigation of such differences seems indicated, particularly given other well-established differences between obese persons with and without BED on a range of eating and psychological variables (Grilo et al., 2010, Grilo and White, 2011 and Grilo et al., 2008). A key step, however, is to confirm the factor structure and validity of the FTSI in clinical samples. The current study, therefore, examined the factor structure and clinical correlates of the FTSI in a consecutive series of obese women with BED. We hypothesized that the factor analysis would result in a valid, one-factor measure of food thought suppression and that FTSI score would be significantly and positively associated with general and specific eating disorder psychopathology.

3.1. Factor structure and internal consistency The original 15-item FTSI, requiring a minimum sample size of 75 (15 items × 5 participants per item; Bryant & Yarnold, 1994) was subjected to analysis. The current sample of N = 128 yielded 8.5 participants per item. We conducted an exploratory factor analysis with SPSS version 19 statistical package, using a maximum likelihood method, as our data demonstrated multivariate normality according to the Omnibus test of multivariate normality (p < .0001). We specified a varimax rotation. The Kaiser–Meyer–Olkin measure of sampling adequacy and the Bartlett's test of sphericity were calculated to assess the appropriateness of the data for factor analysis. The Kaiser–Meyer–Olkin index was 0.89 and the Bartlett's test was significant (p < 0.0001), indicating that the data were appropriate for analysis. Based on the scree plot and eigenvalue test, a one-factor solution was retained. Items were retained if they had a factor loading of 0.45 or greater. This procedure eliminated four items. The items, “There are foods I prefer not to think about,” “I always try to put eating problems out of my mind,” “I often do things to distract myself from my thoughts of food,” and “I have thoughts about food that I try to avoid,” failed to have factor loadings of .45 or above. Table 1 summarizes the resulting one-factor solution, which accounted for 56.1% of the total variance, along with item loadings which ranged from .52 to .91. The final 11-item FTSI yields a range of possible scores of 11 to 55 with higher scores indicating a higher degree of food thought suppression. Internal consistency (reliability) of the revised scale was good as evidenced by Cronbach's alpha of 0.92.