Multisensory food perception: a focus on obese subjects

Food perception and food acceptability are the result of multiple sensory modalities, including visual, olfactory, gustatory, and somatosensory inputs. Some evidence suggests that obese subjects are more prone to be affected by sensory cues than lean subjects. In particular, individuals characterized by higher body mass index (BMI) seem to be associated with a higher susceptibility to external stimuli, such as odor cues. Indeed, among food cues that have an established function in eating behavior, food odors have a key role in affecting food choices, appetite and food consumption. Recent results from our research group showed that multisensory interactions (odor-taste-texture) occur differently according to BMI and, to a lesser extent, to gender. Indeed, the use of aromas and thickener agents in model food, such as a custard dessert, produced stronger sensory interactions (odor-taste, odor-flavor and odor-texture) in subjects with higher BMI, especially in women, compared to the normal-weight subjects. In particular, the addition of an olfactory stimulus signaling high-calorie products, such as butter aroma, modified the perception of different sensory characteristics in a more effective way in obese subjects compared to the control group. Interestingly, subjects with higher BMI perceived the modified samples, added with butter aroma, as sweeter without a real addition of sugar. It seems evident that applying a sensory approach is noteworthy in order to deepen the study of the complex issue of overeating. Indeed, it is possible to hypothesize that sensory cues, especially odors, could affect food perception and consequently food consumption. How the mechanism of brain integration occurs in subjects with different nutritional status should be envisaged to develop new food products with a reduced caloric intake but which are still satisfying for the consumers.