Procedures
The trial used a parallel arm study design, with staff randomly assigning participants to one of the two trial arms: pictorial warnings or control labels. Staff prepared the Mini Mart before a participant’s arrival based on the assigned trial arm. In the pictorial warnings arm, staff applied one of two warning labels (Fig. 
Warning and control labels used in a trial of pictorial health warnings for sugar-sweetened beveragesBefore participants entered the store, staff instructed them to select one snack and one beverage for their child, as well as one household item. This shopping task was designed to mask the purpose of the study. Research staff informed the participants that one of the items would be randomly selected at the checkout counter for the participant to take home. After the shopping task, participants completed a survey programmed in Qualtrics on a computer or tablet in a separate room. Participants received the beverage and cash for a total value of $40 for their participation in the study.