Food hypersensitivity communication across physical and online foodservice menus in Brazil: fragmented regulation and consumer experiences in a mixed-methods study

Inadequate communication of food hypersensitivity in foodservice settings is a recognised risk to consumer safety, yet in Brazil no national regulation governs disclosure in non-prepackaged foods. This study characterises how food hypersensitivity is communicated through physical and online foodservice menus across Brazilian cities, and whether communication differs by the presence of local legislation. A convergent mixed-methods study assessed food hypersensitivity communication in 1,034 menus (323 physical; 711 online) from 18 Brazilian cities (seven with specific legislation, 11 comparators). Menus were classified by format: no information; ingredient-only; emphasised (typographic highlighting); or symbol/code-based (icons, codes or matrices). Four focus groups with 18 participants explored experiences of adults with food allergy, intolerance or coeliac disease, and parents of children with food allergy or coeliac disease. Most menus provided some information, predominantly ingredient-only (physical: 76.2%; online: 88.0%); few provided none (6.5%; 1.0%). Warning messages were uncommon (physical: 11.1%; online: 0.1%). Explicit food hypersensitivity information was more frequent in regulated than unregulated physical menus (regulated: 24.5%; unregulated: 12.7%; p < 0.001). Higher average customer expenditure predicted explicit information (OR = 3.46), and the effect of local regulation depended on establishment type (interaction p < 0.001). Regulation was associated with explicit information among independent establishments (OR = 8.29) but not among chains (OR = 0.55), which provided it at comparable levels regardless of regulatory context. No regulatory effect was observed online, where local laws rarely apply. Consumers valued clear, visually salient formats — icons and complete ingredient descriptions — and identified hidden hypersensitivity-relevant ingredients in composite dishes and inconsistent staff guidance as key barriers, particularly on delivery platforms. This is the first assessment of food hypersensitivity communication in Brazilian foodservice, showing that subnational regulation is associated with more explicit physical-menu communication among independent establishments. Establishments require structured communication and staff training; delivery platforms need mandatory disclosure fields and standardised warnings; policymakers should prioritise structured allergen fields on delivery platforms, with a national framework as a longer-term objective.