Is too much protein bad for your kidneys?

Reviewed and updated · Methodology

Short answer
For adults with normal kidney function, higher protein intakes — up to about 2.2 g per kg body weight per day — do not harm kidney health in the available evidence. People with pre-existing chronic kidney disease (CKD) are a separate case and should follow protein targets set by their physician or renal dietitian, typically lower than the general population.
Details

Multiple systematic reviews (Devries et al., 2018) in healthy adults found no evidence that high-protein diets damage kidney function or markers like GFR.

Short-term elevations in GFR on high-protein diets represent normal kidney adaptation, not injury.

People with pre-existing CKD are a genuine exception. In those populations, moderate protein restriction can slow disease progression, but the targets are individualized.

Staying well-hydrated and getting protein from a mix of animal and plant sources is a reasonable default for high-protein eaters.

Related questions

Do I need to drink extra water on a high-protein diet?

Adequate hydration is sensible at any intake. There is no evidence that high-protein diets cause dehydration, but fluid needs rise with activity, heat, and caffeine intake.

What about gout or kidney stones?

People with a history of uric-acid stones or gout may need to moderate very high purine intakes (e.g., organ meats, some seafood). Plant and dairy proteins are generally fine.

Sources & methodology
  1. NIH Office of Dietary Supplements — Dietary Supplements for Weight LossFederal guidance on protein, supplements, and weight management
  2. ISSN Position Stand: Protein and ExercisePeer-reviewed consensus: 1.4–2.0 g/kg for active adults
  3. NASEM Dietary Reference Intakes — ProteinInstitute of Medicine DRI for protein (RDA 0.8 g/kg, AMDR 10–35%)

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