To study the association between density of stores (food and beverage stores, stores selling only fruits and vegetables, and supermarkets) and the BMI of adults aged ≥20 years in Mexico.

A cross-sectional study was performed. Individual data came from the 2012 National Health and Nutrition Survey, while information on stores was taken from the National Institute of Geography and Statistics’ National Statistics Directory of Economic Units. A weighted least-squares model was estimated to test the association between density of stores and BMI of adults adjusting for sex, age, education, presence of hypertension, diabetes or both, household assets index and marginality index at the municipality level.

Mexico.

An additional 1 sd in the density of fruit and vegetable stores was associated with a reduction of 0·24 (95 % CI −0·37, −0·12) kg/m2 in BMI when the densities of the other stores were at their mean values. For food and beverage store density, a difference of 1 sd was associated with an increase of 0·50 (95 % CI 0·33, 0·67) kg/m2 in BMI, while for supermarkets the corresponding association was a reduction of 0·48 (95 % CI −1·52, 0·56) kg/m2 in BMI.

In places with a higher density of stores that offer unhealthy foods, the BMI of adults tends to be higher.