Policies that require front-of-package (FoP) nutrient warnings are becoming increasingly common across the globe as a strategy to discourage excess consumption of sugary drinks and ultra-processed food. However, a better understanding of the pathway through which FoP nutrient warnings work, as well as a review of how outcomes being measured in recent studies map onto this pathway, are needed in order to inform policy on the most effective FoP label design for reducing purchases of ultra-processed foods. This scoping review describes a conceptual model for how FoP nutrient warnings affect consumer behavior, examines which of these outcomes are currently being measured, and summarizes evidence from randomized controlled experiments. Twenty-two studies which experimentally tested nutrient warnings against a control label or other labeling systems were included for full-text review. Our conceptual model includes attention; comprehension, cognitive elaboration, and message acceptance; negative affect and risk perception; behavioral intentions, and behavioral response, along with other elements such as external factors and interpersonal communications. We found that many studies focused on outcomes such as attention, comprehension, and behavioral intentions, but considerable gaps in the evidence remain, particularly for intermediary steps on the pathway to behavioral change, such as negative affect and social interactions. FoP nutrient warnings were visually attended to by consumers, easy to understand, helped consumers identify products high in nutrients of concern, and discouraged them from purchasing these products, although other labeling systems were perceived as containing more information and performed better at helping consumers rank the healthfulness of products. More research is needed to understand whether and how nutrient warnings work in the real world to discourage consumer purchases of sugary drinks and ultra-processed food.

Background: Front-of-pack (FOP) nutrition labeling is a cost-effective strategy to help consumers make informed and healthier food choices. We aimed to investigate the effect of the FOP labels used in the Latin American region on consumers’ shopping intentions when prompted to make their choices with specific nutrients-to-limit in mind among low- and middle-income Mexican adults (> 18 y).Methods: In this experimental study of an online simulated shopping situation participants (n = 2194) were randomly assigned to one of three labeling conditions: Guideline Daily Amounts (GDA), Multiple Traffic Lights (MTL), or red Warning Labels (WL). Participants were required to view a video explaining how to correctly interpret the assigned label. Primary outcomes were the overall nutritional quality (estimated using the Nutrient Profiling Scoring Criterion [NPSC] and NPSC baseline score) and mean energy and nutrient content of purchases. Secondary outcomes included shopping time variables. We also evaluated the impact of the labels across food categories (ready-made foods, dairy beverages, non-dairy beverages, salty snacks, and breakfast cereals) and sociodemographic subgroups.Results: The MTL and the WL led to a better overall nutritional quality of the shopping cart compared to the GDA (p < 0.05). According to the NPSC score, the WL led to a better nutritional quality across breakfast cereals and salty snacks compared to the GDA (p < 0.05); a similar effect was observed for the MTL among non-dairy beverages (p < 0.05). The MTL and the WL required shorter shopping times compared to GDA (p < 0.05). Across all labeling conditions, the nutritional quality of the shopping cart tended to be lower among those with low income, education and nutrition knowledge levels.Conclusion: WL and MTL may foster healthier food choices in a faster way among low- and middle-income groups in Mexico. To produce an equitable impact among consumers of all socioeconomic strata, efforts beyond simply the inclusion of a communication campaign on how to use and interpret FOP labels will be required.Trial registration: clinicaltrials.gov.NCT04308408Retrospectively registered March 16, 2020.

Widespread use of face coverings is a key public health strategy to prevent the spread of COVID-19. However, few studies have examined why Americans use or do not use face coverings, and little is known about the most effective messaging strategies. This study explored perceptions of face coverings, including motivations and barriers for use, and examined reactions to messaging promoting the use of face coverings. Six virtual focus groups were conducted with 34 North Carolina residents in July 2020. Participants reported high compliance with face covering recommendations but often did not wear them around family, friends, and colleagues. The most prevalent motivation for the use of face coverings was to protect or respect other people, including high-risk populations and individuals. Other motivators were self-protection, responsibility, desire for control, requirements, and expert advice. Barriers included physical and social discomfort, confusion or misinformation, low perceived susceptibility to COVID-19, and perceptions of identity and autonomy. Even among individuals who frequently wear face coverings, there are opportunities to improve compliance. Messaging should highlight how face coverings protect the wearer and others around them, normalize the use of face coverings in social settings, and emphasize requirements. Positive messages that focus on unity, personal experiences and the rationale for face coverings are recommended.

Pictorial warnings on cigarette packs motivate smokers to quit, and yet the warnings’ theoretical mechanisms are not clearly understood. To clarify the role that risk appraisals play in pictorial warnings’ impacts, we conducted a meta-analysis of the experimental literature. We meta-analyzed 57 studies, conducted in 13 countries, with a cumulative N of 42,854. Pictorial warnings elicited greater cognitive elaboration (e.g., thinking about the risks of smoking; d = 1.27; p < .001) than text-only warnings. Pictorial warnings also elicited more fear and other negative affect (d = .60; p < .001). In contrast, pictorial warnings had no impact on perceived likelihood of harm (d = .03; p = .064), perceived severity (d = .16; p = .244), or experiential risk (d = .06; p = .449). Thus, while pictorial warnings increase affective and some cognitive risk appraisals, they do not increase beliefs about disease risk. We discuss the role of negative affect in warning effectiveness and the implications for image selection and warning implementation.