The researchers, publishing in the Journal of Urban Economics, say their study implies that proliferation of Wal-Mart Supercenters, which offer food at highly discounted prices, explains 10.5% of the U.S. rise in obesity since the late 1980s.
but the resulting increase in medical expenditures offsets...consumers? savings from shopping at Supercenters.
http://works.bepress.com/charles_courtemanche/7/