Obesity and Self Control: Evidence from Food Purchase Data

Abstract

In this paper, we examine the relationship between Body Mass Index (BMI) and food purchase behavior using a dataset that links individual-level food purchases, store-level price exposures, and individual-level obesity status. We document novel patterns that are informative for understanding how the relationship between diet and price varies with an individual's obesity status. Specifically, we find that BMI is positively correlated with higher purchase shares of vice goods such as ice cream or potato chips, and higher BMI individuals are more price sensitive in those product categories. In contrast, we do not find any statistically significant relationship between BMI and purchase likelihood or price sensitivity for comparable non-vice product categories. Interestingly, we do not find evidence that higher BMI individuals are more deal sensitive (when controlling for price) or stockpile more in response to deals. Our estimated relationship between BMI and price sensitivity is not moderated by individual habits, obesity related disease conditions, or factors related to an individual's concern about weight.