Out-of-home eating plays an increasingly important role in the American diet and weight. This research studied out-of-home food environment and restaurant choices in one rural county of eastern Alabama, United States, and examined the impact on African American children's weight status. A mixed methods approach was used in this study. Questionnaires were collected for 613 African American children at all four public elementary schools in the county. The healthfulness of restaurants was assessed with the Nutrition Environment Measures Survey-Restaurant (NEMS-R). An agent-based model integrated with Huff's model was developed in order to examine family dining patterns with consideration for individual and community socio-demographics; restaurant location, size, and healthfulness; and the spatial dynamics between consumers and food retailers. We found that this model performed well, as evidenced by validation with the 2013-2014 National Health and Nutrition Examination Survey (p, 0.54-0.96), and by comparison with the original Huff model. Frequency of dining at low-quality full-service restaurants (r = 0.084; p <0.05) was associated with rural children's body mass index (BMI) percentile. These findings may increase public awareness of the importance of family restaurant choices as well as the potential unhealthiness of full-service restaurants.