Is healthy food a luxury for low-income households in the United States?

It seems quite a few of the poor, when they get some extra money, want to keep on buying refined sugar.  Or in other words, it takes quite a bit of income (or is it education?) to “elevate taste.”  Here is the job market paper by Olga Kozlova of Duke University:

This paper explores how the low-income households change the quality of their food basket when they experience a budget increase. I use the variation in the monthly household budget coming from the exogenous variation in the winter temperature that directly affects the heating bills. I show that in response to a higher budget available the expenditure share on healthy food does not increase. I find that households increase the share of expenditure on fruits, but they purchase fruit products with a higher amount of sugar. My findings suggest that there are important trade-offs in policies that subsidize food expenditure because these policies allow low-income households to purchase more of the healthy as well as the unhealthy food products.

Also on the job market, from Northwestern, here is Mara P. Squicciarini, whose job market paper argues that Catholic education held back economic growth in 19th century France.  She also co-edited a book The Economics of Chocolate.