Objective  To investigate the correlation between the consumption of soybean-based complementary food supplements called Yingyangbao (YYB) in Chinese and underweight status among infants and young children in poor rural areas of Henan province.

  Methods  We recruited 2 901 children aged 6 to 24 months with multistage sampling in 10 poverty-stricken counties in Henan province and then conducted body weight measurement among the children and questionnaire survey among the caregivers of the children between June and September 2015. Two-level logistic regression model was used to explore the correlation between YYB consumption and underweight among the children.

  Results  The prevalence of underweight was 11.68% among the children. Two-level logistic regression indicated that YYB consumption of 4 packs or more per week (odds ratio OR = 0.613, 95% confidence interval 95% CI: 0.472 – 0.798; P < 0.001) and consumption of YYB for 7 months or above (OR = 0.395, 95% CI: 0.237 – 0.657; P < 0.001) were reversely correlated with underweight. Comparing with conventional model, two-level logistic regression model fitted the data better and resulted in more robust effect estimation.

  Conclusion  The prevalence of underweight among infants and young children in poor rural areas of Henan province was higher than that of national level and consumption of Yingyangbao can improve the prevalence of underweight among the infants and young children effectively.