Objectives : Five U.S. states have proposed policies to require health warnings on sugar-sweetened beverages (SSBs). SSB health warnings reduce intentions to purchase SSBs, but their effect on actual purchasing behavior remains uncertain. We aimed to evaluate the effect of front-of-package SSB health warnings on SSB purchases.
Methods : In 2018, we conducted a randomized controlled trial in a life-size replica of a convenience store located in Durham, North Carolina, U.S.A. Items were sold at real-world prices and included foods, sugar-sweetened and non-sugar-sweetened beverages, and household products. A convenience sample of 400 adult (age ≥18) SSB consumers (consume ≥12 oz/week of SSBs) were randomly assigned to a health warning arm (SSBs in the store displayed a health warning label modeled after proposed warnings in the U.S.) or a control condition (SSBs displayed a control label). Labels were displayed on the front of SSB containers. Participants selected items for purchase using $10 provided at study start. The primary outcome was SSB calories purchased.
All 400 participants (236 women, 159 men, and 5 transgender people; mean age=29.0 [SD=10.3] years) completed the trial and were included in analyses. Control arm participants were less likely to be Hispanic and to have body mass index in the overweight/obese range than health warning arm participants. Participants in the control arm purchased an average of 143.2 calories from SSBs (SE=9.7), compared to 109.9 calories from SSBs (SE=9.5) in the health warning arm. In intent-to-treat analyses adjusting for Hispanic ethnicity and overweight/obesity, health warnings significantly reduced SSB purchases (adjusted difference, -32.4 calories; 95% CI, -59.5,-5.2; p=0.019). SSB health warnings also reduced the proportion of participants who purchased an SSB from 64% to 50% and the number of SSBs purchased from 0.9 to 0.7 beverages. Results were identical in unadjusted analyses.
Conclusions : Brief exposure to health warnings reduced SSB purchases in this naturalistic randomized controlled trial. Implementing policies to require SSB health warnings could discourage SSB consumption.
Funding Sources :
Funding for this study was provided by the National Center for Advancing Translational Sciences (NCATS) and by an internal university grant.