Objective:

We tested the effectiveness of the I prefer plain water educational strategy used to increase water consumption in elementary school children.

Materials and methods:

A community intervention trial was performed in eight public elementary schools in Mexico City. The schools were randomized into an intervention (IG) and a control (CG) group. Each school was provided water dispensers inside the classrooms. The IG received the educational strategy. The strategy was considered effective if the students increased their water consumption by ≥220 ml.

Results:

Water consumption in the IG increased 167 ml vs. 37 ml in CG (p < 0.001). The goal of the educational strategy for water consumption was achieved in 166/413 children in the IG and 95/364 children in the CG (p < 0.001).

Conclusions:

I prefer plain water, associated with free access to water inside the classrooms, proved to be effective to increase water consumption.