Abstract
<p>A mere glimpse of a food can tell us whether it is savoury or sweet, healthy or indulgent, before we have even tasted it. What structure underlies these visual judgements? Are they driven primarily by food categories, such as fruit, grain, or dessert, by food properties that cut across category boundaries, such as sweet versus savoury, or by some combination of the two? We studied this by collecting over 140,000 triplet judgements in which participants indicated which of three foods “doesn’t belong,” enabling us to reconstruct the representational space humans use to differentiate foods. The resulting space revealed two broad axes: a savoury–sweet continuum and a healthy–indulgent continuum. Food category membership was the strongest single organising principle, outperforming any individual flavour or appraisal dimension, while semantic dimensions explained substantial additional structure. A complementary data-driven analysis recovered a similar structure without access to category labels. Together, these findings show that visual food representations are organised around a categorical scaffold, with continuous semantic properties refining similarity within categories and creating links across category boundaries.</p>