Effects of High-Protein Diets on Renal Function and Body Composition in Adults Without Chronic Kidney Disease: A Systematic Review and Meta-Analysis of Randomised Trials
Abstract
Background: High-protein diets are widely prescribed for weight management and metabolic control, yet concerns persist regarding their impact on renal function, particularly due to diet-induced hyperfiltration.
Objective: We evaluated the effects of high-protein diets compared with normal- or low-protein (NPL) diets on renal function and body composition in adults without chronic kidney disease.
Methods: We systematically searched PubMed, Embase and the Cochrane Central Register of Controlled Trials from inception to May 2026 to identify randomised controlled trials comparing high-protein diets (typically ranging from approximately 25%-35% of total energy intake or ≥ 2.0 g/kg/day) with NPL diets in adults without chronic kidney disease. We defined estimated glomerular filtration rate (eGFR) and serum creatinine as primary outcomes. We evaluated body fat percentage, total fat mass and fat-free mass as secondary outcomes. We performed random-effects meta-analyses using restricted maximum likelihood estimation. We assessed risk of bias with the Cochrane RoB 2 tool and evaluated certainty of evidence using GRADE.
Results: We included 22 randomised controlled trials. High-protein diets increased eGFR compared with control diets (standardised mean difference 0.39, 95% confidence interval 0.09-0.69; I 2 = 74.9%). However, because most studies relied on creatinine-based estimates of renal function, these findings should be interpreted cautiously and may primarily reflect short-term…
How strong is the evidence?
Evidence Hub reads this as a meta-analysis, done in people. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid. Reported size: 1,044 participants or records.
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