J Acad Nutr Diet. 2023 Sep 4:S2212-2672(23)01514-9. doi: 10.1016/j.jand.2023.08.135. Online ahead of print.
BACKGROUND: Given growing interest in warning labels as a form of front-of-pack nutrition label, it is important to better understand the mechanisms via which these labels may exert their effects, especially among those making suboptimal food choices.
OBJECTIVE: To assess the extent to which consumers with the weakest outcomes for objective understanding and choice in no-label conditions were able to improve their understanding/choices after exposure to warning labels on food product options.
DESIGN: Post-hoc analyses of the cross-sectional FOP-ICE study data generated from an online survey that included simulated food choice and nutritional quality ranking scenarios.
PARTICIPANTS/SETTING: 3680 adults from 18 countries: Argentina, Australia, Belgium, Bulgaria, Canada, Denmark, France, Germany, Italy, Mexico, Netherlands, Poland, Portugal, Singapore, Spain, Switzerland, the UK, and the USA.
INTERVENTION: Survey respondents selected their preferred product options and ranked foods according to their healthiness before and after exposure to mock breakfast cereal, cake, and pizza products displaying warning labels.
MAIN OUTCOME MEASURES: Objective understanding and food choice.
STATISTICAL ANALYSES PERFORMED: Within each product category, analyses were conducted on those who initially (i) incorrectly identified the healthiest option and/or (ii) selected the unhealthiest option as their preferred choice. Significant differences between proportions selecting each understanding and choice response option were assessed using two sample z-tests for proportions.
RESULTS: Salience of the warning labels was low: 46% reported noticing the labels while completing the survey. Just over one-third of those aware of the presence of warning labels were able to identify the least healthy option in the post-exposure condition. Around one-half re-selected the least healthy option post-exposure, and just over one-quarter switched to the healthiest option.
CONCLUSIONS: The results indicate warning labels can assist some consumers to improve their food quality assessments and choices. However, design improvements could enhance the salience and interpretability of this label format.