Water Fountain

Water Down Childhood Weight Gain in Elementary School?

Can a simple program to promote drinking water prevent obesity in elementary schools? Well, no. But a new study in Pediatrics does tell us that promotion of drinking water can indeed prevent weight gain in elementary school students.

Many well-intended childhood obesity programs have a nil effect. So it’s delightful to point to a well-controlled study of one that works – even if the effect is modest.

A Sound Cluster Randomized Trial (CRT)

Researchers randomized 1,249 fourth-grade students from 56 classes in 18 schools into a test group of nine schools and a control group of the same size. These were schools in the San Francisco Bay area that serve low-income students. For the test group, the schools installed water stations, conducted schoolwide water promotion, and students received classroom lessons on the benefits of drinking water. This was a year-long promotion. The control group got none of that.

All too often, the design and analysis of cluster randomized studies is inadequate to produce robust findings, So it is gratifying to find that this one suffers from no such problems.

No Effect on Obesity, a Small Effect on Weight Gain

The prespecified primary endpoint for this study was the prevalence of overweight and obesity. The protocol specified two time points after initiation of the program: seven months and 15 months. At seven months there was no effect. But at 15 months, the combined prevalence of overweight and obesity grew more in the control group. For obesity prevalence, researchers noted there was no effect.

A Notable Success

This is a solid win for a sensible intervention. In its press release on this study, the American Academy of Pediatrics reminds us that water is simply a healthier option than sugar-sweetened beverages because they don’t promote weight gain. The researchers say that the small effects they documented for this program are worth celebrating:

“Despite the small effects of school-based obesity prevention programs like Water First, they have the potential to impact large numbers of children at a lower cost than more intensive clinical interventions,”

So, though a water-first program in elementary school has no miracles to offer for preventing childhood obesity, it does appear to help with preventing weight gain. Given that overcoming obesity requires many small steps, this increment of progress is worth claiming.

Click here for the present study, here for a prior study by other investigators, and here for a cost-effectiveness analysis. Thanks to Dean David Allison at the Indiana University School of Public Health for insights on the merits of this CRT.

Water Fountain, photograph by Dori, licensed under CC BY-SA 3.0 US

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August 15, 2023