The potential impact of body mass index, cognitive dissonance, and stigma.

Abstract

We read with interest Ruddock et al. (1) “Believing in food addiction: Helpful or counterproductive for eating behavior?” The article reports two experiments that manipulated participants' beliefs as to whether or not they had food addiction and then had them engage in a taste test. Contrary to the literature reporting that the concept of food addiction has the potential to negate personal responsibility and lead individuals to “overindulge,” participants led to believe they scored high on food addiction ate less than those who believed they had scored lower. On the surface these results are compelling and could lead us to believe that the adoption of the food addiction construct and possibly the broader understanding of obesity as a form of an addiction could assist those struggling with overeating. However, it is thought that there are three alternative and related explanations for the results evident in this study, specifically, body mass index (BMI), cognitive dissonance, and stigma. Firstly and most fundamentally, the authors report that there was no significant difference in BMI between conditions in both studies; however, the mean BMI for either study was not reported. If the BMI of the participants was average, these results are in accordance with Hoyt et al.'s (2) results of inducing the belief that obesity is a disease. This study found that participants of average BMI who believed that obesity was a disease exhibited more concern for weight and dieting than participants with obesity (2). On the contrary, Hoyt et al.'s (2) participants with obesity who believed obesity was a disease were less concerned with their weight and dieting than the participants with obesity in the control group. Further, it is known that food addiction increases with obesity status in the general population, with Pedram et al. (3) finding a prevalence rate of 6.7% in females. This figure indicates that a total of 10.32 participants across the two studies should have been expected to be classified with food addiction, with 0 and 7 being classified with food addiction, respectively. As such, BMI may have been pivotal in the results of Ruddock et al.'s study (1). If the participants were of average BMI and induced to believe they had food addiction, this information may have caused cognitive dissonance, a psychologically uncomfortable state. Cognitive dissonance results when cognitions and behaviors are not consonant, resulting in the feeling of dissonance; self-consistency theory is a theory of cognitive dissonance concerned with situations that evoke inconsistency between self-concept and behavior (4). Therefore this information may have been dissonant with their self-concepts, resulting in the need to reduce the dissonance, and so they consumed less in the snack challenge than those in the low-food addiction group where cognitive dissonance may not have been aroused. Stigma could also explain these results, as those who believed they scored high on food addiction may have felt stigmatized and thus acted in the presumed socially desirable manner exhibiting more restraint on the snack challenge. Meanwhile, those who believed they scored low on food addiction did not feel the same stigma and subsequently did not display the same restraint. Taken together, it is thought that BMI may be fundamental in explaining results of Ruddock et al.'s study (1); however, cognitive dissonance and stigma could have also potentially impacted upon the results. Further, BMI, cognitive dissonance, and stigma could have jointly influenced the results. It would be of great interest to see Ruddock et al.'s study (1) replicated with particular attention to BMI and to ascertain if the results are congruent across BMI categories at a single time point as well as longitudinally.