Association between dietary diversity in complementary feeding and growth and nutritional status among children aged 0–36 months in China: a cross-sectional study

Abstract

Objective To assess complementary feeding practices among Chinese parents and to investigate the associations between dietary diversity in complementary feeding and growth outcomes in children aged 0–36 months. Methods This national cross-sectional study included 26,266 children aged 0–36 months from 33 provinces in China. Participants were recruited through a convenience sampling strategy. Self-reported questionnaires were designed and posted on the website of the China Maternal and Child Health Association, which collected the information of assessing complementary feeding practices and knowledge. Anthropometric indicators (length/height, weight, and weight-for-length/height) were evaluated using World Health Organization growth standards. Dietary diversity was defined based on the daily consumption of multiple complementary food groups. Correlation analyses and multivariable regression models were conducted to evaluate associations between dietary diversity, specific food groups, and growth outcomes. Results A high proportion of children were classified above the 90th percentile for weight across regions (range: 39.39–51.83%). Dietary diversity was positively associated with linear growth in all age groups, with the strongest association observed among children aged 19–36 months (r = 0.2769, p < 0.05). Conversely, dietary diversity was negatively associated with weight-for-length/height in children older than 6 months and with weight gain among those aged 13–18 months (r = −0.0602, p < 0.05). Iron and protein-rich foods, such as liver and animal blood, were underutilized, particularly in younger children. Additionally, 13.13% of parents reported limited experience in complementary feeding, and more than half prioritized DHA supplementation over whole-food diversity. Conclusion Chinese children aged 0–36 months may be at risk of high body weight status. Greater dietary diversity in complementary feeding may support optimal linear growth while helping to mitigate excessive weight gain. Given the observed gap between parental knowledge and feeding practices, targeted nutrition education and guidance on responsive feeding are urgently needed from a public health perspective.