5 Best of 2017: Pediatrics Viewpoints

William T. Basco, Jr., MD


December 28, 2017

In This Article

Is Increased Water Intake Associated With Teen Weight Loss?

The theory that increasing water intake has the potential to limit weight gain may have been extrapolated from cross-sectional studies that demonstrated that children and adolescents who took in more water had lower body mass index (BMI), but there is less experimental data to support the practice for weight loss. A recent randomized trial[2] evaluated increased habitual water intake for 6 months as an intervention to promote weight loss among a small group of 38 adolescents between 12 and 17 years of age with a BMI at least at the 85th percentile. The teenagers were randomly assigned to intervention or control groups, both of which received a standardized weight-reducing dietary intervention. The intervention group was also encouraged to increase water intake to 8 cups daily (and received filtering water pitchers and a water bottle to facilitate this intake) but the control group received no such encouragement.

The standardized dietary intervention for both groups included monthly individual dietary education by a nutritionist, physical activity recommendations, and behavioral counseling (six total sessions) along with daily text messages to the participants. In the course of the monthly sessions, the investigators ascertained how well the teens adhered to these interventions. Over the course of the study, the water intervention group reported a daily intake of water that averaged 4.8 cups of water daily, 1.6 cups more than the control group's intake.

There was no difference in the change of BMI z-score between the two groups, but both groups experienced some improvement (average reduction in BMI z-score of 0.1). In weight terms, the mean weight change among both groups was less than 1 kg. The authors concluded that encouraging 8 cups of water intake daily in overweight and obese adolescents did not show a benefit over dietary counseling and support.


This Viewpoint was likely highly read because obesity is such a common pediatric condition, and practitioners will see multiple patients per day who are either overweight or obese. Considering that both groups in this study experienced a very intensive dietary intervention, it is quite possible that the intensity of the dietary intervention masked any improvement that may have otherwise resulted from increased water intake. Certainly, the trial shows that one can't be overconfident in suggesting increased water intake as a weight loss recommendation, but given the relatively low baseline water intake in the groups, recommending that adolescents drink more water is nevertheless not a bad idea.


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