How Much of Food Price Changes Are to Blame for the American Weight Size Increase?" (with Veronika Dolar)

In the last thirty years, Americans gained an average of twenty-two pounds and changed their eating habits in two dramatic ways. First, they eat more, as evidenced by a twenty-three percent increase in average total daily calorie intake. Second, they altered the type of food that they eat, as total daily calories intake coming from products with added sugars, added fats, and flour and cereals increased by thirty-seven percent, while consumption of fruits and vegetables, dairy, and meat, eggs, and nuts stayed roughly constant.  

Over the same period of time, the real price of added sugars, added fats, and flour and cereal products has declined by sixteen percent, while the real price of fruits and vegetables, dairy, meat and poultry increased by twenty-five percent.  

We propose a stochastic dynamic optimization model to study the impact of changes in food prices on the eating habits and weight of Americans. After calibrating the model using evidence from medical research, we find that changes in  food prices account for less than ten percent of the increase in average weight of Americans. We compare our results to existing estimates in the literature.