Within this project, we explored the neurocognitive mechanism of distracted eating. Olfactory and gustatory performance under different levels of distraction was systematically compared between lean and overweight participants. Odors and tastes were delivered using constant-flow olfactometry and a modular pump gustometer. An ecologically valid paradigm, a Tetris game utilizing two difficulty levels (low vs. high) was used as distraction task.
We observed that overweight participants rated intensity of taste and flavor stimuli as significantly diminished compared to lean participants within the high distraction condition. Thus, we assume changes on behavioral level induced by distraction are orchestrated by neural alternations that might be a unique biological marker of obesity.
Noteworthy, the hedonic properties of gustatory stimuli were also significantly influenced by distraction. Both lean and obese participants perceived the stimuli as significantly less pleasant within high-distraction compared to low-distraction condition.
Moreover, lean participants also perceived pleasantness of different food-associated odors as significantly decreased within the condition of high compared to low distraction. Contrary to our assumptions, the intensity perception of olfactory stimuli was not affected by distraction.
Within our sample, the overweight participants perceived intensity of olfactory and gustatory stimuli as significantly higher in comparison to the lean participants. This supports the assumption that overweight participants have higher sensitivity towards food-related chemosensory stimuli.
In conclusion, our findings suggest that the neurocognitive mechanism of distracted eating is different in effect and structure between the lean and obese populations and distracted eating is a contributing factor to obesity.