Metabolomics in malnourished children: A scoping review of emerging metabolites

Background: Malnutrition in children includes both undernutrition and overnutrition, each contributing to distinct metabolic disruptions with long-term health consequences. Understanding these biochemical patterns can improve how malnutrition is detected and managed. Objective: This scoping review aimed to explore and summarize current research on the metabolites associated with various forms of childhood malnutrition. Methods: A broad literature search was conducted using PubMed, Web of Science, EBSCO, and Google Scholar to identify studies that analysed metabolic profiles in children experiencing different types of malnutrition, including obesity, stunting, and underweight. Results: The findings revealed consistent changes in pathways related to amino acids and lipids. Obesity in children was associated with elevated levels of branched-chain amino acids (BCAA) and acylcarnitines, showing emerging associations with insulin resistance. Stunted growth was linked to lower levels of essential amino acids and polyunsaturated fatty acids. Several studies also reported reduced concentrations of specific lipid metabolites, particularly lysophosphatidylcholines, across various malnutrition conditions. Some metabolic markers, such as BCAAs and leptin, were found to correlate with growth and nutritional status. However, results varied across different populations. Conclusion: The findings suggest that metabolomics has potential as a complementary tool for understanding malnutrition pathophysiology. However, additional research is necessary to validate these metabolites and explore their applicability in clinical practice. The observed variations in metabolic profiles across different populations highlight the importance of context-specific interpretation when applying these metabolites in clinical or research settings.