Systematic review and meta-analysis found that malnutrition was associated with poor cognitive development

Aim: Malnutrition is a major public health issue that has been associated with high susceptibility for impaired brain development and mental functioning. However, to date studies on this topic have not been collated and appraised. This systematic review and meta-analysis investigated the association between malnutrition and cognitive development. Methods: We searched the MEDLINE, Scopus, CINAHL, Embase PsycINFO and Cochrane Library databases in English up to 8 December 2020. All studies reporting an association between nutritional status and cognitive development were included. p values of less than 0.05 were considered statistically significant and the results are reported as standardised mean differences (SMD), 95% confidence intervals (95%) and I2 statistics. Results: We included 12 studies comprising 7,607 participants aged 1 to 12 years. Children with malnutrition had worse scores than controls for the Wechsler Intelligence Scale (SMD −0.40; 95% CI −0.60 to −0.20; p < 0.0001; I2 77.1%), the Raven's Coloured Progressive Matrices (SMD −3.75; 95% CI −5.68 to −1.83; p < 0.0001; I2 99.2%), visual processing (SMD −0.85; 95% CI −1.23 to −0.46; p 0.009; I2 11.0%) and short memory (SMD 0.85; 95% CI −1.21 to −0.49; p < 0.0001; I2 0%) tests. Conclusion: Normal cognitive development requires access to good and safe nutrition.