BackgroundSince sugar-sweetened beverages (SSB) may contribute to the development of overweight in children, effective interventions to reduce their consumption are needed. Here we evaluated the effect of a combined school- and community-based intervention aimed at reducing children’s SSB consumption by promoting the intake of water. Favourable intervention effects on children’s SSB consumption were hypothesized.MethodsIn 2011-2012, a controlled trial was conducted among four primary schools, comprising 1288 children aged 6-12 years who lived in multi-ethnic, socially deprived neighbourhoods in Rotterdam, the Netherlands. Intervention schools adopted the ‘water campaign’, an intervention developed using social marketing. Control schools continued with their regular health promotion programme. Primary outcome was children’s SSB consumption, measured using parent and child questionnaires and through observations at school, both at baseline and after one year of intervention.ResultsSignificant positive intervention effects were found for average SSB consumption (B -0.19 litres, 95% CI -0.28;-0.10; parent report), average SSB servings (B -0.54 servings, 95% CI -0.82;-0.26; parent report) and bringing SSB to school (OR 0.51, 95% CI 0.36;0.72; observation report).ConclusionsThis study supports the effectiveness of the water campaign intervention in reducing children’s SSB consumption. Further studies are needed to replicate our findings.Trial registrationCurrent Controlled Trials: NTR3400