Obese individuals have higher preference and sensitivity to odor of chocolate.

The worldwide epidemic of obesity has inspired a great deal of research into its causes and consequences. It is therefore surprising that so few studies have examined such a fundamental part of eating behavior: our sense of smell. The aim of the present study was to examine the differences in olfaction in obese and nonobese individuals. Participants (n = 40) categorized as obese (body mass index ≥ 30) or nonobese (body mass index < 30) completed a standardized olfactory threshold test to an ecologically valid food-related odor (chocolate), followed by a taste test. We found that compared with those not obese, obese individuals rated the chocolate odor as more pleasant and were substantially more sensitive to the odor. There was also evidence that their sense of taste was more acute for sour and salty tastants. Correlational analyses further revealed that those measures of olfaction and taste were positively associated with body mass index. These findings suggest that obese individuals show increased sensitivity and preference for an odor associated with energy dense foods. They also suggest that differences in our sense of smell offer a promising area for future research in obesity.