Approach
Participants completed an online survey programmed in Qualtrics. Qualtrics randomized participants to 1 of 5 trial arms using a simple allocation ratio: (1) control (calorie labels only on all products); (2) green labels (green “choose often” labels added to healthy products with no additional labels on products not meeting healthfulness criteria); (3) single traffic light labels (hereafter, traffic light labels; green “choose often,” yellow “choose sometimes,” and red “choose rarely” labels added to healthy, moderately healthy, and unhealthy products, respectively); (4) physical activity labels (labels showing calorie content expressed as minutes of physical activity required to burn those calories added to all products); or (5) nutrient warning labels (“high in” warning labels added to products exceeding thresholds for sugar, sodium, saturated fat, or calories) (