New research is underway to document the evidence base for the connection between WASH and undernutrition. Currently, USAID, with WHO and UNICEF, is collecting evidence and documenting concrete programming actions to integrate WASH and nutrition to prevent diarrheal disease and undernutrition and improve child health outcomes. Too often, low-cost, high-impact WASH interventions are overlooked. Yet these simple actions can prevent diarrhea and undernutrition even in hygienechallenged environments. This brochure highlights some of these WASH interventions.