Discussion
SSBs
DISEASE
In this study, we found that pictorial health warnings reduced parents’ purchases of SSBs for their children by reducing the perceived healthfulness of SSBs. Additionally, pictorial warnings changed parents’ purchase behavior by lowering their intentions to serve SSBs to their children, in line with health behavior theories (e.g., the Theory of Planned Behavior) that posit that behavioral intentions predict behavior change [We found that perceived healthfulness of SSBs partially explained how SSB warnings reduced parents’ likelihood of purchasing an SSB for their child. SSB warnings led to lower perceptions that SSBs are healthy for their child, which in turn was associated with a lower likelihood of purchasing of SSBs. Additionally, higher perceived likelihood that SSBs could lead to health problems for their child was associated with a lower likelihood of parents purchasing SSBs (though perceived disease likelihood was not a significant mediator). These findings are in line with a prior study that found that parents’ healthfulness and risk perceptions mediated the impact of health warnings on hypothetical selection of SSBs for their children [In our study, message reactions did not mediate the impact of SSB warnings on parents’ purchases of SSBs. These results stand in contrast to two prior studies with adults, finding that message reactions including emotions and thinking about harms, explained how SSB warnings affected adults’ purchase behaviors and intentions [The differences in mediators between prior studies of adults and the present study of parents suggest that that the process of reacting to health messages might function differently when making purchasing decisions for oneself, compared to when making decisions about another person (perhaps especially when that person is one’s child). One possible explanation for these differences is that message reactions are processes that reflect an individual’s thoughts and feelings, but do not involve considerations for others. Another possibility is that parents are less informed about what beverages are healthy for their children than for themselves, giving warnings more room to changing healthfulness perceptions. Consistent with this hypothesis, prior research shows that parents tend to believe certain types of SSBs including fruit drinks and sports drinks are healthy options for their children [Overall, we found many small effects in our models, which mirrors prior research that health communication interventions often lead to a small (~ 5%) change in a desired outcomes [Strengths of this study include the randomized controlled design. We also assessed an objective purchasing outcome in the context of naturalistic experimental store setting with a wide variety of real products. Limitations include that participants had only one exposure to the warning labels and mediators and outcomes were measured at only one timepoint. Additional studies should establish patterns of mediation over a longer time period and explore serial mediation using longitudinal data. Finally, it is possible that our surveys did not measure all possible mediators of warning labels; future studies including qualitative research could shed light on potential psychological mediators not assessed in this study.