In this paper we examine the role of relative food prices in determining the recent increase
in body weight in Italy. Cross-price elasticities of unhealthy and healthy foods estimated
by a demand system provide a consistent framework to evaluate substitution effects, when a
close association is assumed between unhealthy (healthy) foods and more (less) energy-dense
foods. We used a dataset constructed from a series of cross-sections of the Italian Household
Budget Survey (1997-2005) to obtain the variables of the demand system, which accounts for
regional price variability. The relative increase of healthy food prices was found to produce
nontrivial elasticities of substitution towards higher relative consumption of unhealthy foods,
with effects on weight outcomes. In addition, these changes were unevenly distributed among
individuals and were particularly significant for those who were poorer and had less education