Impacts of warning labels on ultra-processed foods among Latino adults: A randomized trial

Introduction. Ultra-processed foods (UPFs), defined as foods in group 4 of the NOVA classification system, are a key contributor to chronic disease in the United States. Front-of-package warning labels ('warnings') offer a promising strategy to help Americans reduce consumption of UPFs. Requiring warning labels on UPFs could help reduce consumption of these foods. However, the effects of UPF warnings are largely unknown. The impact of warning labels on UPFs among Latino adults was examined. Study design. Online randomized trial. Setting/participants. 4,107 Latino adults (49% limited English proficiency) in the US. Intervention. Participants viewed one of three labels: control labels displaying barcodes; identity warnings stating 'WARNING: Ultra-processed food'; or health warnings stating 'WARNING: Consuming ultra-processed food and drinks can cause weight gain, which increases the risk of obesity and type 2 diabetes'. Main outcome measures. Participants viewed four UPF products displaying their randomly assigned labels. Participants indicated whether the product was UPF (primary outcome) and rated perceived healthfulness of the product, intentions to purchase the product, and perceived message effectiveness (secondary outcomes). Results. Identity warnings (70% correct) and health warnings (67% correct) both led to higher correct identification of UPF compared to control labels (54%, p<.001), with the identity warning having a larger impact than the health warning (p=.007). Compared to the control label, the identity warning and health warning both elicited higher perceived message effectiveness and lower perceptions of healthfulness and purchase intentions (p<.001 for all outcomes) with no significant differences between UPF labels. The impact of the health warning label (vs. the control label) on correct identification of UPF was greater for participants with high education (p=0.012) compared to those with low education, and participants with limited English proficiency (p=0.001). Conclusions: UPF warnings may help consumers identify UPFs and influence product perceptions and intentions.