International students offer an unique opportunity to study the extent to which environment causes obesity. Because international students have an imperfect ability to choose their destination and are less aware of the social and cultural conditions in and around the university campus we argue that the prevalence of obesity in the surrounding area is plausibly exogenous to international students’ choice of university. In this study, we survey international students studying at 43 public universities across the United States. We use this data to study the effect of prevalence of obesity in a particular region on the BMI levels of the international students. We find statistically significant effects on the changes in BMI levels of the students. Students studying in areas with lower prevalence of obesity show a significantly lower increase in their BMI compared to those studying in areas with higher prevalence of obesity. Evidence suggests that the environmental characteristics of a region have a direct effect on the BMI levels of individuals.