THE FOOD PRICES / BODY MASS INDEX RELATIONSHIP: THEORY AND EVIDENCE FROM A SAMPLE OF FRENCH ADULTS.

What would be the effect of a "fat tax" on obesity? This paper shows that the sign of the price-weight correlation is unclear, as variations of food price have a direct effect on weight through changes in energy intakes, and an indirect (income) effect that affects energy expenditure. Food expenditures data are used to examine the link between the prices of 16 food groups and the distribution of the Body Mass Index among French adults. We find positive correlations for ready-meals and snacks, and negative correlations for sea products and fruits. It is thus unlikely that the epidemic of obesity will react in the short-term to nutritional taxes.