Does High Protein Hurt Your Kidneys?
Summary: In adults with healthy kidneys, a 2018 meta-analysis of 28 studies found that higher protein intakes did not change kidney function differently from normal intakes; if you already have kidney disease, set your protein with your doctor.
On this page
- The short answer
- What GFR is
- The main study: Devries 2018
- Other sources on safety
- If you have kidney disease
- What KetoDick says
- Questions to ask your doctor
- Related
The short answer
| Your situation | What the evidence says |
|---|---|
| Healthy kidneys | Higher protein did not change kidney filtration differently from normal protein (Devries et al., 2018) |
| Kidney disease or reduced kidney function | Reviews flag caveats (Pesta & Samuel, 2014); your doctor sets your protein |
| Not sure | Ask for a kidney function test before raising protein |
What GFR is
GFR stands for glomerular filtration rate. It is a measure of how well your kidneys filter your blood. A falling GFR over time is a sign of reduced kidney function.
It is usually estimated from a standard blood test. If you have had routine blood work, your doctor may already have a recent number.
The main study: Devries 2018
| Detail | What it found |
|---|---|
| Type | Systematic review and meta-analysis |
| Studies | 28 |
| People | 1,358 adults without kidney disease |
| "Higher protein" meant | At least 1.5 g/kg per day, at least 20% of calories, or at least 100 g a day |
| Result | Changes in GFR did not differ between higher and normal or lower protein intakes |
| Source | Devries et al., 2018 |
The "higher protein" cut-offs matter. 1.5 g/kg sits inside the 1.2 to 1.6 g/kg range used for weight loss (see How much protein on keto?). So the intakes this guide discusses are the intakes this study tested.
What the study does not tell you:
- It covered adults without kidney disease. It says nothing about people who already have it.
- It measured kidney filtration, not other outcomes such as kidney stones. For stones, see Does keto cause kidney stones?.
Other sources on safety
- EFSA describes protein intakes up to about twice its 0.83 g/kg reference as commonly eaten and considered safe for adults (EFSA, 2012). Twice the reference is about 1.7 g/kg.
- The accepted range for protein is 10 to 35% of daily calories (National Academies, 2005).
- A 2014 review of high-protein diets covers how they work and lists reported caveats, including effects in people with pre-existing kidney disease (Pesta & Samuel, 2014).
If you have kidney disease
This is the case where you need your doctor, not a guide. Kidney disease, reduced kidney function, a single kidney, or a history of kidney problems all change how much protein is right for you.
Keto can also change other things your kidneys handle:
- Electrolytes. Keto often means more sodium and sometimes potassium or magnesium supplements. With kidney disease, these need medical guidance. See Potassium and magnesium.
- Medications. Some medicines are dosed based on kidney function. See Medications.
- Diabetes. If you have type 2 diabetes, blood-sugar medicines may need adjusting on keto, and your doctor will want to watch kidney function too. See Who should talk to a doctor first.
What KetoDick says
- Kidney issues, type 2 diabetes or pre-diabetes: he tells people in these groups to involve their doctor, because a dark ketone strip or an electrolyte change could matter for them (video GojQvo_2GS0; video lbRPlGZ3Rvw).
- Supplements: he says to check with a doctor before taking potassium or magnesium supplements or making big sodium changes (video 9r2Y74AnjUQ; video lbRPlGZ3Rvw).
- A protein ceiling: in an early video he says an adult male liver can process about 220 g of protein a day before urea builds up and the liver and kidneys hit limits (video cTGYIFOTPl8).
- Err high on protein for most people, because too little can mean muscle loss (video UygKGoP_BtA).
How that compares: his advice to bring kidney issues to a doctor matches the evidence. His 220 g ceiling is his own figure; the evidence pages used for this guide do not give a daily ceiling in grams. For most women, 220 g is far above the 1.2 to 1.6 g/kg range (for a 70 kg woman, that range is 84 to 112 g).
Questions to ask your doctor
- What was my most recent eGFR, and is it normal for my age?
- Is there any reason I should limit protein?
- What daily protein amount is right for me?
- Do any of my medications depend on kidney function?
- Is it safe for me to take potassium or magnesium supplements, or to add salt?
- Should we recheck kidney function after a few months on this diet?
More: Talk to your doctor about keto and Blood tests before keto.
Related
Guide
- Chapter 5: Protein on keto
- How much protein on keto?
- Too much protein on keto?
- Protein after 50
- Who should talk to a doctor first
Blog
Videos
- Are dark keto test strips dangerous?
- Making sense of electrolytes
- Beginner keto questions and tips by a random guy
Last verified: 2026-10-31