Sociodemographic disparity in the diet quality transition among Chinese adults from 1991 to 2011.

Background/objectives: This study investigates secular trends in diet quality distribution and related socioeconomic disparity from 1991 to 2011 in the Chinese adult population.

Subjects/methods: The analysis uses the 1991-2011 China Health and Nutrition Survey data on 13 853 participants (6876 men and 6977 women) aged 18-65 with 56 319 responses. Dietary assessment was carried out over a 3-day period with 24-h recalls combined with a household food inventory. We tailored Alternative Healthy Eating Index 2010 (named as tAHEI) to measure diet quality and performed quantile regression to investigate shifts in tAHEI scores at different percentiles and used mixed-effect linear regression to examine average diet quality trend and potential sociodemographic disparity.

Results: The energy-adjusted mean tAHEI scores increased from 36.9 (36.7-37.1) points in 1991 to 50.3 (50.1-50.5) in 2011 for men (P<0.001) and from 35.6 (35.4-35.8) to 46.9 (46.7-47.1) for women (P<0.001). The covariate-adjusted score of polyunsaturated fatty acids increased by 6.8 (6.6, 7.0) and 7.0 (6.9, 7.2), and the score of long-chain (ω-3) fats increased by 5.3 (5.2, 5.4) and 5.3 (5.2, 5.5) in men and women, respectively, whereas the cereal fiber and red meat scores decreased slightly. Increasing tAHEI score occurred across the entire distribution, and diet quality transition varied across sociodemographic groups.

Conclusions: Chinese diet quality is far from optimal, with moderate improvement over a 21-year period. Findings suggest that nutritional intervention should give priority to low-income, low-urbanized communities and southern provincial adults with low diet quality in China.