The effectiveness of an egg-based intervention on improving the nutrition of poor school-age children in China: A quasi-experimental assessment.

Objectives: Although egg-based interventions are effective in alleviating undernutrition for infants and toddlers, little is known regarding their effectiveness for children in remote and poor areas of China. For policy and intervention implications, the aim of this study was to examine the effects of offering one hard-boiled egg per school day to school-age children in less-developed areas of China.

Methods: This analytical sample included 346 school-age children. Children in the treatment group received one egg per school day. Applying propensity score weighting to the difference-in-difference models, this study examined the effects of the egg intervention on child nutrition status measured in height-for-age Z score (HAZ), weight-for-age Z score (WAZ), and body-mass-index-for-age Z score (BMIZ).

Results: After applying propensity score weighting, the average treatment effect (ATE) and the average treatment effects on the treated (ATT) estimations showed that the increase in HAZ scores from wave 1 to wave 3 for the program participants was 0.28 points higher compared with the increase in HAZ scores from wave 1 to wave 3 for the control group (P < 0.05). The ATE and the ATT estimations showed that the increase in WAZ scores from wave 1 to wave 3 for the program participants was 0.50 and 0.49 points higher compared with the increase in WAZ scores from wave 1 to wave 3 for the control group (P < 0.001). Regarding BMIZ score improvement from wave 1 to wave 3, the program participation had relatively larger effects by 0.57 and 0.55 points based on the ATE and ATT estimations (P < 0.001), respectively.

Conclusions: The egg intervention can be an effective intervention to improve child development in less-developed areas of China.