Food price policies and the distribution of Body Mass Index: Theory and empirical evidence from France

This paper uses French food expenditures data to examine the effect of the prices of 23 food product categories on the distribution of Body Mass Index (BMI) in a sample of French adults. A dynamic choice model that uses standard assumptions from Physiology is developed. It is shown that the slope of the price-BMI relationship is affected by the individual's Physical Activity Level (PAL). When the latter is unobserved, identification of price effects at conditional quantiles of the BMI distribution requires quantile independence between PAL and the covariates, especially income. Then, using quantile regression results, unconditional BMI distributions can be simulated for various price policies. It is found that increasing the price of beverages, fats and sugars and sweets by 10%, and decreasing the price of fruits and vegetables by 10% would reduce the prevalence of overweight and obesity by 7 and 5 percentage points respectively.