Effect of oral nutrition supplements on anthropometric and functional parameters among community-dwelling older adults: a systematic review and meta-analysis of randomized controlled trials

Background Oral nutrition supplement (ONS) prescription in older adults is affordable for preventing malnutrition through the use of multiple nutrients and energy products. However, there is a gap in knowledge regarding the benefits of ONS supplementation on anthropometric and functional parameters in malnourished older adults without complicated conditions, known as community-dwelling older people. Methods Electronic databases, including PubMed/Medline, SCOPUS, Web of Science, and the Cochrane Central Register of Controlled Trials, were searched to answer this question through August 10, 2023. The study adhered to the PRISMA guidelines and was registered on PROSPERO. The Cochrane risk of bias tool assessed the quality of randomized controlled trials (RCTs). The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to evaluate the certainty of evidence. In total, 12 RCTs (n = 1320) were initially included. Results ONS had a positive effect on body weight (weighted mean difference (WMD): 1.33, 95% CI: 0.94, 1.72, P = 0.00) with moderate certainty, BMI (WMD: 0.36, 95% CI: 0.06, 0.68, P = 0.02), calf circumference (WMD: 0.27, 95% CI: 0.08, 0.46, P < 0.001) with low certainty and midarm circumference (WMD: 0.38, 95% CI: -0.14, 0.89, P = < 0.15, I2: 87.2 P < 0.00) with very low certainty. Significant improvements in grip strength (WMD: 1.012, 95% CI: 0.37, 1.65, P < 0.00) and a slightly positive change in gait speed (WMD: 0.04, 95% CI: 0.004.0.083, P = 0.03, I2:0.0, P:0.72) were also observed. Conclusion ONS in community-dwelling older persons without complicated conditions can also have beneficial effects in terms of anthropometric and functional parameters.