Effect of Dietary Interventions on Phase Angle in Patients with Chronic Kidney Disease Undergoing Dialysis: A Systematic Review and Meta-Analysis.

CONTEXT: Phase angle (PhA), derived from bioelectrical impedance analysis, is inversely associated with malnutrition, a common condition in chronic kidney disease (CKD) managed through dietary therapy. Although evidence from oncology and sports medicine suggests nutritional interventions may improve PhA, supporting its potential use as a marker of therapeutic efficacy, data from CKD remain limited.

OBJECTIVE

The impact of nutritional-related interventions on PhA values in patients with CKD and undergoing dialysis was evaluated in this systematic review and meta-analysis.

DATA SOURCES: A systematic literature search for clinical trial studies was conducted in the PubMed, Scopus, Web of Science, CINAHL, and Embase databases up to September 2025.

DATA EXTRACTION: Eligible clinical trials included adults with CKD and undergoing dialysis, applying any dietetic intervention as compared with a control, and reporting PhA variations. Meta-analysis was conducted only on data from randomized clinical trials (RCTs) and analyzed by stratification according to intervention details.

DATA ANALYSIS: A total of 14 studies (n = 9 RCTs) comprising 969 participants were included in the review. Overall, there was no influence of dietetic intervention accompanied or not by an exercise-related component, compared with standard of care (ie, no intervention), on PhA values (mean difference [MD] = 0.22; 95% CI, -0.20 to 0.63; P < .001; I2 = 78%), nor did the isolated effect of the dietary component (MD = 0.26; 95% CI, -0.22 to 0.73; P < .001; I2 = 80%) or use of amino acids or a protein-based unimodal intervention (MD = 0.49; 95% CI, -0.19 to 1.17; P < .001; I2 = 73%) have an impact.

CONCLUSION

Our meta-analysis did not show influences of dietetic intervention on PhA among patients with CKD who are undergoing dialysis. However, given low number of RCTs and important risk of bias, high-quality RCTs are needed to verify our findings.

SYSTEMATIC REVIEW REGISTRATION: PROSPERO no. CRD42024601056.