A between-groups experiment examined the salience of front-of-package (FOP) symbols. Adults from Canada, the US, Australia, and the UK completed an online survey (n = 11,617). Respondents were randomized to view cereal boxes displaying one of 11 FOP label conditions for 'high' levels of sugar and saturated fat: control (no FOP symbol), red circle, red 'stop sign', magnifying glass, magnifying glass + exclamation mark, and 'caution' triangle + exclamation mark, plus each of these five conditions accompanied by a 'high in' text descriptor. Participants identified the amount of saturated fat and sugar in the product ('low'/'moderate'/'high'). Participants were more likely to correctly identify the product as 'high' in saturated fat or sugar when shown the stop sign, triangle + exclamation mark, red circle, or magnifying glass + exclamation mark symbols incorporating 'high in' text (p < 0.01). The magnifying glass was the least effective symbol. The stop sign (37.7%) and triangle + exclamation mark (22.0%) were most frequently selected as the best symbol for indicating high nutrient amounts. Overall, FOP labels with 'high in' descriptions, red color and intuitive 'warning' symbols (e.g., stop signs, exclamation marks, 'caution' triangles) were more effective at communicating high levels of nutrients of public health concern in a time-limited environment.
Keywords: adult; diet; experiment; front-of-package; nutrition label.