Predicting appetitive response to food odours from expected gustatory properties and taste-liking phenotypes: a cross-sectional study

Background: Food intake is influenced by hedonic mechanisms involving the pleasure from consumption (liking) and the appetitive drive to eat a food (wanting). While orthonasal olfaction occurs in anticipation to food intake, taste signals occur during consumption itself. However, how hedonic values from individual taste preferences are transferred onto food odours to influence their motivational value remains unclear.Objective: This study examines to what extent wanting for orthonasally presented odours is influenced by their perceived sweetness and savouriness and the individual liking for sweet or savoury tastes.Methods: Forty-three participants completed a taste identification and rating task involving six sweet and six savoury stimuli of increasing concentration. Pleasantness ratings were used to characterise individual sweet- and savoury-liking phenotypes using bounded negative quadratic functions. Subsequently, participants rated the perceived sweetness, savouriness and wanting of nine food odours. Linear mixed-effects models predicted odour wanting from taste liking. Model performance was compared using leave-one-subject-out cross-validation.Results: Most participants exhibited an inverted U-shaped hedonic response to both taste qualities, with sweet taste generally being preferred over savoury taste. Taste liking profiles interacted with the perceived sweetness and savouriness of food odours to exert separate, orthogonal effects on wanting for foods associated with them. An additive model, where odours were located on a sweet-savoury space, outperformed a subtractive model, where odours were located on a sweet-savoury spectrum, with a higher correlation between predicted and observed values (∆r = -0.24; t(42) = −2.79, p = .008; 95% CI [–0.41, –0.07]; Cohen’s d = -0.43).Conclusion: Taken together, our findings characterise a mechanism by which odours elicit food craving through taste associations. Our results have the potential to inform behavioural interventions and encourage healthier and more sustainable dietary patterns.