In adults, relationships between religiosity and positive health behaviors have been established; however, similar studies among emerging adults has not been explored. This study examined the relationship between multiple dimensions of religiosity, physical activity, fast food intake, and obesity among emerging adults. Data are from 1,319 emerging adults participating in the National Longitudinal Study of Adolescent Health during Wave IV (ages 18-29). Females were highly religious on all dimensions of religiosity. Path models showed high levels of religious practice encouraged eating less fast food, and more prayer time increased physical activity levels. More religious practice was associated with lower incidence of obesity; increasing time spent in prayer, however, heightened the risk for obesity. Thus, dimensions of religiosity in emerging adults constructed in a different ways with fast food intake, physical activity, and obesity.