Association between water consumption and body weight outcomes in children and adolescents: a systematic review.

Objective: Water is recommended to replace sugar-containing beverages for prevention of childhood obesity. Because this recommendation is not evidence-based yet, the existing evidence on the association between water consumption and body weight outcomes was summarized.

Methods: In a systematic review, studies were retrieved from four electronic databases (MEDLINE, EMBASE, CINAHL, Cochrane) and further search methods. Studies including children aged 2-19 years on the association between water consumption and any body weight-related outcome were eligible.

Results: Out of 3,023 retrieved records, 13 studies were included: four longitudinal and nine cross-sectional studies. One cross-sectional analysis in one longitudinal study was additionally included, resulting in ten cross-sectional analyses. One non-randomized controlled study and two observational longitudinal studies showed that increased water consumption reduced the risk of overweight or body mass index. Another observational longitudinal study did not indicate this association. Six cross-sectional analyses found a direct association between water consumption and at least one body weight outcome. Four cross-sectional analyses did not show any association.

Conclusions: On the cross-sectional level, higher water consumption seems to be associated with higher weight status. In contrast, longitudinal studies suggest a weight-reducing effect of water consumption, but evidence for a causal association is still low.