Made from full fat soybean powder and micronutrients such as calcium, iron, and vitamins, YYB was introduced to improve nutritional status of rural infants and children who are six to 36 months old.
The meta-analysis, carried out by researchers from Harvard T.H. Chan School of Public Health, Tsinghua University, and Peking University, was published in scientific journal Nutrients.
The meta-analysis sought to study the effectiveness of the YYB program based on 1) anthropometric outcomes, 2) haematological parameters, 3) child development outcomes, and 4) disease prevalence.
Eight English databases, including Cochrane Library, and three Chinese databases such as China National Knowledge Infrastructure, were searched from January 2001 to June 2019 to identify the YYB intervention studies.
A total of 26 quasi-experimental, post-only, concurrent-control studies, and pre-post studies were analysed.
The analysis found that consuming YYB increased haemoglobin (Hb) concentration, height, and weight.
For example, a pooled analysis of seven post-only studies with concurrent-control showed Hb concentration rose by 4.43g/L in the group which took YYB.
On the other hand, the analysis of six post-only studies with concurrent-control showed that children who consumed YYB were on average, 2.46cm taller and 0.79kg heavier than the control groups.
As for pre-post studies, it was found that Hb concentration rose by 6.58g/L, while height and weight increased by 2.46cm and 0.72kg respectively.
“In this study, YYB complementary food supplement was found to be associated with significant increases in children’s Hb concentration, height, and weight, and significant reductions in children’s risk of anaemia and stunting, in quasi-experimental studies conducted in China,” the researchers concluded.
As the meta-analysis is based on observational studies, the researchers acknowledged that other biases could have affected the results of the studies.
They have thus called for future studies to include randomised trials to determine the causal effects of YYB.
“Despite evidence indicating the potential benefits of YYB, there is clearly a need for more robust evidence, including randomised control trials and rigorously implemented evaluations.”
They also suggested for future research to identify gaps in program implementation in places where YYB is already deployed.
Background and future plans
According to data from the World Bank, in 2013, around seven million Chinese children were stunted and two million were underweight.
Anaemia is also a severe problem, particularly in the rural areas, where 28% of the rural children between 6 and 12 months old and 21% between 13 and 24 months are estimated to be anaemic.
The Chinese government has thus introduced the YYB to improve nutritional status of these children.
This year, the government launched the “Upgrade of YYB Plan”, which will provide YYB to infants and children in 823 poor counties.
In 2017, the government issued a national nutrition strategy for 2017–2030 that prioritised the nutritional status of children in their first 1000 days, and YYB was included as a key intervention for rural and poor populations.
The Effect of the Yingyangbao Complementary Food Supplement on the Nutritional Status of Infants and Children: A Systematic Review and Meta-Analysis
Authors: Zhihui Li, et al