Malnutrition in infants aged 6-23 months in China's poorest rural counties from 2016 to 2021: cross sectional study

To assess trends and differences in child malnutrition by population subgroups among infants aged 6-23 months in China's poorest rural counties.

Six consecutive cross sectional surveys were conducted annually.

The study was conducted in 116 counties in 19 provinces from 2016 to 2021, representing China's 832 poorest counties.

A total of 210 088 participants were selected through a multistage cluster sampling procedure; all participants were infants aged 6-23 months.

Prevalence of anaemia, stunting, wasting, overweight, and growth status in children (measured by length-for-age and weight-for-length z scores).

Four main malnutrition forms were prevalent in 2016: anaemia (prevalence 18.3%), stunting (7.5%), wasting (4.7%), and overweight (3.1%). The prevalence of any two coexisting malnutrition forms was low. All four forms of malnutrition decreased from 2016 to 2021. Anaemia decreased by more than half, with an annual reduction rate of 9.11% (95% confidence interval (CI) 4.83% to 13.20%). Stunting was reduced by over a third, with an annual reduction rate of 10.44% (7.56% to 13.22%), which is faster than the World Health Organization's target of 3.9%. Differences in child growth by county gross domestic product quarters were small and decreased over time, but growth differences related to education persisted. Infants whose mothers completed education up to primary school level had approximately twice the risk of stunting (adjusted rate ratio 2.29 (95% CI 1.87 to 2.81)) and wasting (1.73 (1.40 to 2.13)) compared with children whose mothers had an education level of a college degree or above. Boys had poorer growth and higher anaemia than did girls. For all outcomes, differences related to sex and education were greatest at 6 months of age.

Education related inequalities in growth of infants persists, with these differences particularly affecting children whose mothers completed education only up to primary school level.