The Mobility of Income-related Inequality in Food Preferences Among Chinese Adults: a Population-based Longitudinal Study

Abstract

Background:This study aimed to investigate the income-related inequality of food preference and its mobility in the long run, and to quantify the determinants’ contributions of socioeconomic inequality mobility in food preference in China.Methods:The data were sourced from the China Health and Nutrition Survey (CHNS) conducted in 2006, 2009, 2011 and 2015, respectively. A study sample of 3940 adults were included for analysis. Five preselected questions were used to construct a summary food preference index. Cross-sectional and longitudinal concentration indices were used to measure the income-related inequality in food preference at a certain time and for a period, respectively. Health-related income mobility index was used to measure the gap between cross-sectional and longitudinal income-related health inequality concentration indices. Decomposition analysis was used to decompose income mobility index into its determinants.Results:The mean scores of food preference increased from 17.641 in 2006 to 18.881 in 2015. The richest people had the highest mean scores of food preference compared to other income groups in each year. Age, gender, income, education, and dietary knowledge score were positively associated with healthy food preference. The concentration indices of food preference score on income in each year were all positive, indicating that there was pro-rich inequality in food preference score with the rich having higher preference scores in each period. The income mobility index of food preference was -0.1426 after 4 periods, indicating that the degree of pro-rich inequality in food preference was larger than that at the baseline in the long run. Decomposition analysis showed that being married and living in Western China made healthy food preference more concentrated among the rich in the long run. Whereas increasing age and dietary knowledge contributed to making healthy food preference behavior less concentrated among the rich in the long run.Conclusions:The cross-sectional measure of food preference score inequality was underestimated in the long run. Our study suggests that people with decreased income could be taken as targeted population in future public intervention measures, and narrowing the regional gap between Eastern and Western China could be strengthened in future Chinese policies.