Household water security matters greatly for child nutrition outcomes in the global South. Water’s role in sanitation/hygiene, via diarrheal disease, is cited as a primary mechanism here. Yet, the relationship between Water along with Sanitation and Hygiene (WASH) and child stunting remains inconclusive. Water-related mechanisms outside of the traditional scope of WASH might assist with explaining this.
We aim to test the mediating role of reduced dietary diversity as an additional potential mechanism in linking worse household water access to increased risk of early childhood stunting, separating its effects from sanitation and diarrhea among children (as a proxy for hygiene) and taking into account regional water availability.
We use nationally representative India Demographic and Health Survey (2015-16) data for 58 038 children aged 6 to 23 months, applying generalized structural equation modelling to estimate water’s direct and indirect effects (as mediated through dietary diversity and access to sanitation) on a child’s likelihood of being stunted.
Suboptimal water access is significantly associated with elevated likelihood of child stunting. More than 30% of the effect is indirect. In the context of low water access and availability, children’s dietary diversity alone mediates more than 20% of its total effect on child stunting.
Beyond the WASH mechanisms, household water access affects child stunting indirectly, mediated through its impacts on children’s dietary diversity. These mediating effects are also moderated by regional water availability. Water interventions in low-water regions should help reduce children’s risk of nutrition-related stunting in households with lowest water access.

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