It needs minor revision in places but the results need more attention.
See Murayama, N. (2015). Effects of socioeconomic status on nutrition in Asia and future nutrition policy studies. Journal of nutritional science and vitaminology, 61(Supplement), S66-S68. Darmon, N., & Drewnowski, A. (2008). Does social class predict diet quality?. The American journal of clinical nutrition, 87(5), 1107-1117. The issues raised in the well quoted Darmon and Drewnowski paper need to be considered more.