When does a warning matter? Individual and product-related factors associated with front-of-pack label responses

Front-of-pack labelling is a public health initiative to promote healthier food choices. This study aimed to examine the association of Brazilian warning labels (WLs) with consumers' purchase intentions according to consumer label reading profiles (LRPs), product motivation (hedonic/utilitarian) and claims. This was done by identifying and characterising LRPs as an individual factor. A cross-sectional online survey (n = 370), predominantly female, young and highly educated, assessed label use frequency, food choice motives, and purchase intention for seven categories of packaged foods with/without WLs. Cluster analysis identified three LRPs: Detailed, Moderate, and Practical Readers. Logistic regression explored predictors of LRPs, and three linear mixed models evaluated purchase intention based on LRPs, WL presence, and product type, controlled for demographic characteristics. WLs were consistently negative, yet with small effect, driver of purchase intention. A stronger effect size was observed when displayed on utilitarian products and those carrying claims, compared with hedonic or without claims. LRPs were the strongest predictor of purchase intention, followed by the presence of claims, regardless of WLs. Health, natural content, and ethical concerns emerged as key drivers of Detailed label engagement, while those motivated by familiarity showed lower levels of engagement (Practical Readers). Moderate Readers, who showed intermediate levels of engagement, were the only to show a within-group reduction in purchase intention associated with WLs. In conclusion, the effectiveness of WLs appeared contingent on the interplay between individual label reading profiles and product context, functioning most effectively when challenging specific positive drivers rather than as a universal deterrent.