Effect of a School-Based Health Literacy Intervention on Sugar-Sweetened Beverage Choices Among Children and Adolescents in China: A Cluster-Randomised Controlled Trial

Objectives
We examined the effectiveness of a school-based intervention focusing on sugar-sweetened beverage (SSB) harms and nutrition-label understanding among children and adolescents.

Study design
We conducted a school-based, two-arm, cluster-randomised controlled trial among upper-primary and lower-secondary students in six Chinese schools. The trial was embedded within the 2022 wave of the Health and Nutrition Panel Survey (HNPS-2022). Classes were the unit of randomisation; within each school and target grade, classes were randomly assigned to a video (<5 min) on SSB harms and nutrition labels or eyesight protection. The trial included a real choice experiment (RCE) and a discrete choice experiment (DCE). Primary outcomes were the probability of selecting a full-sugar fermented milk drink (FMD) at actual beverage selection in the RCE, and the direction and relative importance of preferences for prespecified beverage attributes in the DCE. We used ANCOVA and mixed logit models.

Results
Between September and October 2022, 24 classes were randomly assigned to control (12 classes; 653 students) or intervention (12; 649); 1269 students were analysed (641 control and 628 intervention). At actual beverage selection, 367/641 (57.3%) control participants selected the full-sugar rather than the low-sugar FMD, compared with 228/628 (36.3%) intervention participants (adjusted absolute difference −0.21, 95% CI -0.28 to −0.15; p < 0.0001; adjusted odds ratio 0.39, 95% CI 0.30 to 0.51; p < 0.0001). In the DCE, beverage profile (a combination of beverage type and sugar content) had the highest relative importance (49.6%), followed by price (38.4%). The intervention shifted preferences towards healthier options, especially among primary school students.

Conclusions
A brief health literacy intervention supported healthier immediate beverage choices, but sustained SSB prevention will require clearer, child-friendly sugar information and school policies that make healthier beverage options easier to choose.