Point-of-sale sugar-sweetened beverage (SSB) warning posters vs. control posters were associated with reductions in school store SSB purchases made by Guatemalan adolescents

Abstract

Objective:

We examined whether point-of-sale warning posters, compared to control posters, reduced Guatemalan adolescents’ purchases of sugar-sweetened beverages (SSBs) at school stores.

Design:

We used a difference-in-differences approach (4 weeks baseline, 4 weeks treatment). Our primary analysis compared two schools assigned to an intervention warning poster to one school that displayed a control poster. Based on purchase transaction data, the outcomes were volume of sugar-sweetened beverages, beverage kcal, and sugar purchased per transaction.

Setting:

Three private schools in Guatemala City, Guatemala

Participants:

Students between 12 and 18 years of age

Results:

Our primary analysis found that the warning poster decreased the overall volume of sugar-sweetened beverages (in ounces) that adolescents purchased in the warning poster intervention schools (-2.27 oz. 95% CI=[-2.70, -1.85]) compared to the control school. This reduction was driven by a decrease in sugar-sweetened beverage purchases (OR= 0.64 95% CI=[0.49, 0.86]). The warning posters were associated with a significant reduction in likelihood of purchasing a beverage with kilocalories (calories) (OR= 0.68 95% CI=[0.49, 0.92]). These changes were associated with a significant overall decrease of sugar purchased (-5.54g 95% CI=[-6.69, -4.39]). The posters were associated with a significant increase of non-SSB purchases in the intervention schools compared to the control school (OR= 1.53 95% CI=[1.16, 2.02]).

Conclusion:

Our results suggest that messages that warn adolescents about the high sugar content in SSBs may be an effective, low-cost way to modestly reduce purchases of these drinks. These findings provide evidence to support national front-of-package labeling, currently being considered in Guatemala.