Abstract
National data suggest that children are not consuming enough water. Experimental evidence has linked increased water consumption to obesity prevention, and the National AfterSchool Association has named serving water as ones of its standards for healthy eating and physical activity in out-of-school time settings. From fall 2010 to spring 2011, twenty Boston afterschool program sites participated in the Out-of-School Nutrition and Physical Activity (OSNAP) initiative, a group-randomized trial investigating nutrition and physical activity policies and practices that promote child health. Researchers used data from OSNAP to study the key factors that influence the implementation of practices that promote water intake. Aspects of the organizational capacity of the afterschool programs, characteristics of the providers, and the community context were hypothesized to impact changes in children's water consumption. This chapter demonstrates the effectiveness of an afterschool intervention on increases in children's water consumption. It also outlines the substantial influence that implementation factors can have on the effectiveness of an obesity prevention intervention, highlighting the importance of understanding how interventions are delivered in real-world settings.