غذا برای فکر: بررسی رابطه بین سرکوب افکار غذایی و نتایج مرتبط با وزن

The current study sought to extend previous eating behaviors and thought suppression literature by assessing the relationship between food thought suppression and weight-related outcomes. Three hundred and twelve overweight/obese community men and women completed self-report measures of thought suppression, weight history, and eating behaviors. Women were more likely than men to endorse food thought suppression, as were individuals who currently were dieting, when compared with those nondieters. Food thought suppression also predicted binge eating, food cravings, and other eating disordered symptoms. Results have implications for obesity and support further exploration of third wave interventions, such as Acceptance and Commitment Therapy and Mindfulness, in the treatment of obesity.

In a seminal study, researchers instructed participants to suppress thoughts about a white bear (Wegner, Schneider, Carter, & White, 1987). Participants were unsuccessful at completely suppressing the target-thought and also reported a “rebound,” or increase, in white bear thoughts after the suppression period (Wegner et al., 1987, p. 7). Wegner (1994) developed the Ironic Processes Theory to explain the findings. The theory suggests that the outcomes of thought suppression include an immediate increase in target thoughts following instructions or attempts to suppress thoughts; an increase in target thoughts following suppression; and an increased priming of the to-be-suppressed thoughts as measured by Stroop tasks (i.e., hyperaccessibility; Wenzlaff & Wegner, 2000). The importance of examining the relationship between thought suppression and eating behaviors has been stressed in the literature (Polivy, 1998, Ward et al., 1996 and Wenzlaff & Wegner, 2000). The aforementioned outcomes of thought suppression (e.g., hyperaccessibility) have been demonstrated experimentally with individuals attempting to suppress food-related thoughts (Dejonckheere et al., 2003 and Smart & Wegner, 1999). Dieting individuals may be even less able to suppress food- and weight-related thoughts when compared to nondieting individuals (Giannopoulos, 2001, Harnden et al., 1997 and O'Connell et al., 2005), particularly if they are obese (Soetens & Braet, 2006). Suppressing food-related thoughts may not only increase the thoughts but also may alter individuals' behavior. Researchers theoretically linked thought suppression to bingeing (Ward et al., 1996) but few studies have examined the behavioral consequences of instructed suppression. Johnston, Bulik and Anstiss (1999) asked cravers and noncravers of chocolate to suppress thoughts about chocolate. Following the suppression period, and regardless of craving status, participants worked harder at a computer game to earn chocolates when compared to the nonsuppression control group. If women of a healthy weight respond to thought suppression by seeking more food, perhaps the unique response to thought suppression experienced by obese individuals may lead to more dramatic behavioral consequences such as binge eating. Making certain food forbidden increased thoughts of the food but did not result in increased food intake (Mann & Ward, 2001). The study, however, may have failed to replicate the experience of individuals who utilize thought suppression because participants were forbidden to eat certain foods but were not instructed to suppress thoughts. Additionally, participants' body mass indices (BMIs) were not reported. The sample consisted of undergraduates, and studies utilizing similar populations reported participant BMIs within the healthy range (e.g., Harnden et al., 1997). The participants may have managed their weight effectively, therefore limiting the generalizability to overweight or obese individuals. An exploratory investigation randomized thirty participants to a suppression or control condition and further categorized by weight and high/low restraint (Pop, Miclea, & Hancu, 2004). Two weeks of suppression resulted in increased food-related thoughts, regardless of weight, and increased food intake in restrained overweight/obese participants. The published abstract of this experiment did not include the age or sex of the participants. Regardless of the participant demographics, results certainly support further exploration of food-related thought suppression within an overweight/obese population. There appears to be a linear relationship between weight and utilization of food thoughts suppression, with healthy weight, overweight, and obese undergraduate women endorsing progressively higher levels of food thought suppression (Barnes, Fisak, & Tantleff-Dunn, 2010). Food thought suppression also predicted the young women's eating disorder symptomotology. Conversely, among a group of binge eaters, suppression of negative affect did not lead to increased food intake (Dingemans, Martijn, Jansen, & van Furth, 2009). However, researchers collapsed participants among weight categories rather than comparing healthy weight individuals to overweight/obese participants who may be more likely to experience the negative consequences of thought suppression (Pop et al., 2004 and Soetens & Braet, 2006). Taken together, the literature suggests that attempting to suppress food and weight-related thoughts may lead to increases and hyperaccessibility of the thoughts (Soetens & Braet, 2006 and Wenzlaff & Wegner, 2000) and individuals may even binge-eat (Ward et al., 1996), seek out food (Johnston et al., 1999), or increase food intake as a result of thought suppression (Pop et al., 2004). However, existing research generally is limited by samples of young, healthy weight undergraduates. Of the scant literature examining thought suppression within overweight or obese individuals, most have utilized an adolescent population and collapsed male and female participants rather than examine potential sex differences. Recent findings suggest that adolescents may respond differently to suppression than adults (Soetens & Braet, 2007), overweight/obese individuals respond differently than healthy weight individuals (Pop et al., 2004), and women rely on thought suppression more than men (Barnes, Klein-Sosa, Renk, & Tantleff-Dunn, in press). The current study sought to determine if food thought suppression was related to binge eating and food cravings as both may be related to obesity and other eating disorder symptomotology (Hudson et al., 2007 and Weingarten & Elston, 1990White, Whisenhunt, Williamson, Greenway, & Netemeyer, 2002). Previous literature will be extended by the use of an overweight/obese sample of men and women recruited from the community. The current study tested the following hypotheses: 1. women and current dieters will be more likely to utilize food thought suppression than men or nondieters; 2. individuals with a tendency to utilize general thought suppression will be more likely to attempt to suppress food-related thoughts; 3. food thought suppression will predict weight-related outcomes (e.g., food cravings, binge eating) after accounting for the general tendency to suppress thoughts.

Men and women were compared on the potential covariates of current BMI and age. Independent samples t-test revealed no significant differences between women (M = 32.93, SD = 6.74) and men's (M = 31.78, SD = 5.95) BMI, t(310) = 1.46, p = .145, or women (M = 40.24, SD = 12.08) and men's (M = 39.45, SD = 12.35) age, t(308) = .53, p = .600. Therefore, age and BMI were not included as covariates in sex comparisons. To test the first hypothesis, a 2 (dieting/not dieting) by 2 (men/women) ANOVA was conducted. There were significant main effects for sex, F(1, 278) = 15.39, p < .0005, η2 = .052, and dieting, F(1, 278) = 20.45, p < .0005, η2 = .069. The interaction was not significant, p = .35. Evaluation of the means indicated that women (M = 31.03, SD = 14.53) were more likely than men (M = 23.93, SD = 10.37) to utilize food thought suppression, and individuals who endorsed currently dieting (M = 33.13, SD = 15.24) endorsed higher levels of food thought suppression than nondieters (M = 24.58, SD = 10.58). Pearson product–moment correlations were computed to test the second hypothesis. There was a significant positive correlations between the WBSI and the FTSI, r(273) = .459, p < .0005. To test the third hypothesis, hierarchical multiple regressions were conducted. The first step included sex and BMI, the second step included the WBSI, and the third step the FTSI (see Table 1 for regression analyses and Table 2 for standardized coefficients).