Effect of dietary interventions on kidney function in adults with obesity without chronic kidney disease: a systematic review and meta-analysis of randomized controlled trials

Why clinicians should know about it

• Picked for Nephrology (top studies of the week, 19 July 2026).

Abstract

OBJECTIVE: This study aimed to systematically evaluate the effects of dietary interventions on kidney function in adults with obesity without chronic kidney disease (CKD). METHODS: A comprehensive literature search was conducted in PubMed, Web of Science, Embase, Cochrane Library for randomized controlled trials. Random-effects meta-analyses calculated standardized mean difference (SMD), with subgroup analyses by glomerular filtration rate (GFR) assessment method (estimated GFR [eGFR] vs. measured GFR [mGFR]). RESULTS: Eighteen trials involving 1,438 participants were included. Dietary interventions showed no significant effect on GFR (SMD: 0.06; 95% CI: -0.20 to 0.32; p = 0.642). In subgroup analyses, eGFR increased significantly whereas mGFR showed a non-significant reduction (p = 0.0005 for subgroup differences). No significant effect was found for urinary albumin excretion rate (UAER) (SMD: -0.04; 95% CI: -0.39 to 0.30; p = 0.765). Creatinine clearance (CrCl) showed a significant increase (SMD: 0.22; 95% CI: 0.03 to 0.41; p = 0.030). CONCLUSION: Dietary interventions showed inconsistent effects across kidney function measures in adults with obesity without CKD. Although significant improvements were observed in certain kidney function-related indices (eGFR and CrCl), the available evidence did not indicate improved true filtration or reduced urinary albumin excretion. Importantly, these findings suggest that the apparent renal effects of dietary intervention depend on how kidney function is assessed. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/view/CRD420261297927, CRD420261297927.

Abstract as published, via PubMed.