Predicting Appetitive Response to Food Odors from Expected Gustatory Properties and Taste-Liking Phenotypes in a...

Food intake is influenced by hedonic mechanisms involving the pleasure from consumption (liking) and the appetitive drive to eat a food (wanting). Taste is a key driver of liking, whereas orthonasal olfaction elicits wanting. However, how hedonic values from individual taste preferences are transferred onto food odors to influence their motivational value remains unclear.

This study examined the extent to which wanting for orthonasally presented odors is influenced by their perceived sweetness and savoriness and the individual's liking for sweet or savory tastes.

In total, 43 participants completed a taste identification and rating task involving 6 sweet and 6 savory stimuli of increasing concentration. Pleasantness ratings were used to characterize individual sweet- and savory-liking phenotypes using bounded negative quadratic functions. Subsequently, participants rated the perceived sweetness, savoriness, and wanting of 9 food odors. Linear mixed-effects models predicted odor wanting from taste liking. Model performance was compared using leave-one-subject-out cross-validation.

Most participants exhibited an inverted U-shaped hedonic response to both taste qualities, with sweet taste generally being preferred over savory taste. Taste liking profiles interacted with the perceived sweetness and savoriness of food odors to exert separate, orthogonal effects on wanting foods associated with them. An additive model, where odors were located on a sweet-savory space, outperformed a subtractive model, where odors were located on a sweet-savory spectrum, with a higher correlation between predicted and observed values (Δr = -0.24; t(42) = -2.79, P = 0.008; 95% confidence interval: -0.41, -0.07; Cohen's d = -0.43).

Taken together, our findings characterize a mechanism by which odors elicit food craving through taste associations. Our results have the potential to inform behavioral interventions and encourage healthier and more sustainable dietary patterns.