Measuring the food environment and its effects on obesity in the United States: a systematic review of methods and results.

We identified fifty-one peer-reviewed studies that geospatially analyzed the relationship between the community nutrition environment (CNE) and obesity. Eighty percent of studies found at least one significant association between the CNE and obesity. However we calculated the proportion of studies that found at least one significant association between the CNE and obesity in the expected direction for each food store type and measurement technique, and the proportion across the different store types and measurement techniques was just 32%. Different methods for classifying, locating, and analyzing food stores produced mixed results and challenged direct study level comparison.