Reduction in sugar-sweetened beverages is not associated with more water or diet drinks.

OBJECTIVE The Dutch Obesity Intervention in Teenagers (DOiT) is a school-based randomised controlled trial that was effective in decreasing the consumption of sugar-sweetened beverages among adolescents. The present study examined, using mediation analysis, whether this decrease in consumption of sugar-sweetened beverages could be explained by an increase in the consumption of water or diet drinks. DESIGN Participants completed a questionnaire about their beverage consumption at baseline and at 8 months (immediately post-intervention), 12- and 20-month follow-ups. A series of multi-level linear regression analyses were performed to examine water and diet drink consumption as potential mediators of the intervention effect on the consumption of sugar-sweetened beverages. SETTING Eighteen Dutch secondary schools. SUBJECTS A total of 747 adolescents (mean age: 12·7 years). RESULTS In addition to the DoiT intervention effect of a reduction in the consumption of sugar-sweetened beverages at 8 months (-284 ml/d; 95 % CI -420, -148) and 12 months (-260 ml/d; 95 % CI -360, -160), there was also a significant reduction in diet drinks at 8 months (-52 ml/d; 95 % CI -89, -16). There was no significant difference in water consumption at any follow-up. The decrease in sugar-sweetened beverage consumption could not be explained by an increase in water or diet drink consumption at any time point. CONCLUSIONS Interventions aimed at reducing sugar-sweetened beverage consumption may be effective without changing consumption of other beverages. Reducing sugar-sweetened beverages was, however, a main message of the DOiT intervention. It is possible that a concomitant promotion of water may have resulted in a greater increase in water intake and replacement of sugar-sweetened beverages with water.