اثر سرکوب افکار بر رفتار غذایی در مصرف کنندگان غذای محدود و غیرمحدود

Recent research has shown that suppressing food related thoughts can cause a subsequent increase in consumption relative to groups not suppressing, or thinking about food. The present study examined whether the effects of thought suppression on subsequent eating behaviour would interact with participants restrained eating status. One hundred and sixteen female participants were split into three groups. One third suppressed thoughts of chocolate, one third thought about chocolate and the final third thought about anything they wished. Following this, participants took part in a task where they rated two brands of chocolate on several taste characteristics. Participants were unaware that the dependent variable was the amount of chocolate consumed and not taste preference. Participants also completed measures of dietary restraint, craving, guilt and thought suppression. Results indicated that restrained eaters in the suppression condition consumed significantly more chocolate than restrained eaters in the expression or control condition. Participants low on restraint ate statistically equivalent amounts in all three groups. In addition, participants reporting frequent use of thought suppression (assessed by the White Bear Suppression Inventory) reported greater chocolate cravings.

The number of chocolates consumed and times participants reported thinking about chocolate were non-normally distributed. Therefore, scores on both measures were square root transformed prior to all analyses. However, for clarity untransformed means are reported throughout. Participants were divided (by median split) into restrainers and non-restrainers on their scores on the restraint scale.1 This variable was then used as an additional between subjects factor in further analyses. The first analysis investigated the main experimental hypothesis by examining the amount of chocolate consumed by group (suppression vs. expression vs. control) and restraint status (restrainer vs. non-restrainer) using between subjects ANOVA. Results indicated a main effect of group F(2, 110) = 4.86, p = .01, η2 = .08, no main effect of restraint F(1, 110) = 2.92, p = .09, η2 = .02, but a significant interaction of group and restraint F(2, 110) = 3.04, p = .05, η2 = .05. Tests of simple effects indicated that non-restrainers demonstrated no differences in consumption between the suppression, expression and control groups (p > .44 in all cases). However, for restrained eaters the suppression group consumed significantly more than the expression and control groups (p = .0001 and p = .02 respectively). The control and expression groups consumption was statistically equivalent (p = .16). See Fig. 1 for means. Alternatively, for the control and expression conditions there were no differences in the amount consumed for restrainers and non-restrainers (p = .28 and p = .43 respectively). However for the suppression group the restrainers consumed significantly more than the non-restrainers p = .007.