Discrepancy between implicit and explicit preferences for food portions in obesity

Abstract

We investigated the implicit preference for food portion in obesity using the affective priming paradigm. Primes representing different portions of fast food (small, medium, big) were used to assess participants’ readiness to respond to a positive or negative target word. A self-reported affective rating of food portion and a portion judgment task were administrated to determine the explicit preference for food portion and portion misperception, respectively. The results of the affective priming paradigm showed an implicit preference for big food portions in the obese group. No implicit preference for food portion was found in the non-obese group. The explicit preference measure of food portion showed a rather negative attitude for big portions in the obese group, whereas the non-obese group reported no explicit preference for food portion. Thus, unlike the non-obese group, the obese group showed clear discrepancies between implicit and explicit preferences for food portion: obese participants demonstrated an implicit, but not explicit preference for big food portions. These results could not be attributed to a misperception of food portion, as revealed by the portion judgment task. The current findings suggest that social desirability might conceal self-reported preference for food portion and/or that obese individuals are less aware of their internal preferences.