The Effects of Ying Yang Bao on Nutritional Status of Children Aged 6-60 Months in Underdeveloped Rural Areas of China.

The Ying Yang Bao (YYB) intervention, a national policy in China, has been implemented for over two decades. Most previous studies have focused only on the short-term effects of YYB, while the long-term effects remain unexplored. This study was designed to evaluate the long-term effects of YYB in children aged 6-60 months. A sample of 4666 children was divided into intervention and control groups. Information on basic characteristics, physical examination, YYB consumption, etc., was obtained annually from 2018 to 2021. T-tests or chi-square tests were used to compare differences between the groups for continuous or categorical variables. Children in the intervention group showed greater incremental improvements in hemoglobin levels and physical development ( p < 0.05). Prevalence of anemia, underweight, and stunting were lower in the intervention group than in the control group (all p < 0.05). Two-level regression models were constructed to assess the long-term effects of YYB. YYB reduced the risk of anemia and wasting by 37% (OR: 0.63, 95% CI: 0.52-0.75) and 49% (OR: 0.51, 95% CI: 0.39-0.67), respectively. This study indicates that YYB could significantly improve the nutritional status of children aged 6-60 months in underdeveloped rural areas of China.