Young adulthood is a critical age for weight gain, yet scant research has examined modifiable contextual influences on weight that could inform age-appropriate interventions.The aims of this research included describing where young adults eat and purchase food, including distance from home, and estimating the percentage of eating/purchasing locations contained within GIS-generated buffers traditionally used in research.Forty-eight participants (aged 18–23 years, n=27 women) represented diverse lifestyle groups. Participants logged characteristics of all eating/drinking occasions (including location) occurring over 7 days (n=1237) using PDAs. In addition, they recorded addresses for stores where they purchased food to bring home. Using GIS, estimates were made of distances between participants' homes and eating/purchasing locations. Data collection occurred in 2008–2009 and data analysis occurred in 2010.Among participants living independently or with family (n=36), 59.1% of eating occasions were at home. Away-from-home eating locations averaged 6.7 miles from home; food-shopping locations averaged 3.1 miles from home. Only 12% of away-from-home eating occasions fell within -mile residential buffers, versus 17% within 1 mile and 34% within 2 miles. In addition, 12%, 19%, and 58% of shopping trips fell within these buffers, respectively. Results were similar for participants residing in dormitories.Young adults often purchase and eat food outside of commonly used GIS-generated buffers around their homes. This suggests the need for a broader understanding of their food environments.