Distraction suppresses high-fat flavor perception

Distraction during eating contributes to overeating, and when habitually eating with distraction, this may contribute to the development of obesity. One of the proposed mediating mechanisms is the suppression of intensity perception in odor and taste. The effect of distraction on fat intensity perception in flavor, the multisensory combination of odor, taste, and other sensory aspects, is still unknown. In this study, 32 participants (22 women) performed a flavor perception task while also performing a distracting working memory task. In each trial, participants were instructed to observe and memorize a string of 3 (low cognitive load) or 7 (high cognitive load) consonants. Then they received a small quantity of a high- or low-fat chocolate drink, and after that, they were asked to select the string they tried to memorize from three answer options. Last, they rated the intensity and fattiness of the flavor. As intended, in the working memory task, we observed that with a high cognitive load (relative to a low cognitive load), accuracy decreased and response times increased. Regarding perception of the flavors, we observed that overall, high-fat drinks were rated as more intense and fattier. Cognitive load and fat content interacted, such that for the low-fat drink, intensity and fattiness ratings were similar under both cognitive loads; however, under the high cognitive load (relative to the low cognitive load), intensity and fattiness ratings for the high-fat drink were lower. Our results show that distraction can impact the perception of fat in high-fat drinks. If distraction primarily reduces perception of high-fat foods, this may pose a particular risk of overeating high-calorie foods.