Effects of nutritional interventions on the physical development of preschool children: a systematic review and meta-analysis

Background: There is a significant correlation between diet and delayed growth and development in children. However, the evidence for the crucial role of dietary interventions in children's growth and development health remains inconclusive. This meta-analysis sought to comprehensively evaluate the effects of nutritional interventions on children's physical development. Methods: Articles published from January 2007 to December 2022 were retrieved from the PubMed, Embase, Cochrane Library, Wanfang, and China National Knowledge Infrastructure (CNKI) databases. Statistical analysis was conducted using Stata/SE 16.0 software, as well as Review Manager 5.4 software. Results: The meta-analysis included a total of 8 original studies. The total sample comprised 6,645 children aged <8 years. The results of meta-analysis were as follows: (I) there was no significant difference in the body mass index (BMI)-for-age z scores between the nutritional intervention group and the control group [mean difference (MD) =0.12, 95% confidence interval (CI): -0.07, 0.30]. Thus, the nutritional interventions did not significantly improve the BMI-for-age z scores; (II) when the nutritional intervention period was <6 months, there was no significant difference in the weight-for-height z scores between the nutritional intervention group and the control group (MD =0.47, 95% CI: -0.07, 1.00), but when the nutritional intervention period was >= 6 months, the nutritional interventions significantly improved the weight-for-height z scores (MD =0.36, 95% CI: 0.00, 0.72); (III) a nutritional intervention period >= 6 months cannot significantly improved children's height-for-age z scores; (4) When the nutritional intervention period was <6 months, there was no statistically significant difference in the weight-for-age z scores between the nutritional intervention group and the control group (MD =-0.20, 95% CI: -0.60, 0.20), but when the nutritional intervention period was =6 months, the nutritional interventions significantly increased children's weight-for-age (mean difference =2.23, 95% CI: 0.01, 4.44). Conclusions: Different nutritional interventions had a slight improvement effect on children's physical growth and development. However, the effect of the short-term nutritional interventions (<6 months) was not obvious. In clinical practice, it is recommended that nutritional intervention programs be formulated that can be implemented for longer periods. However, due to the limited literature included, further research is needed.