“High-protein diets damage healthy kidneys.”
High-protein diets have not been found to damage healthy kidneys in randomized trials.
If your kidneys are healthy, eating more protein is not a kidney risk you need to worry about. The people who do need to be careful are those with kidney disease, which often has no symptoms, so a simple blood and urine test is worth it if you have risk factors.
Choose a protein intake that fits your goals, and if you have diabetes, high blood pressure or another kidney risk factor, ask for a kidney test before going high-protein.
Safety note: People with chronic kidney disease need a protein target set with their care team, because kidney nutrition guidelines give specific protein advice by stage of disease. More than 1 in 7 US adults has chronic kidney disease, most without symptoms early on, and diabetes, high blood pressure, heart disease, a family history of kidney disease and older age all raise the risk.
Talk to a healthcare professional if: you have kidney disease or an abnormal kidney test, or you have diabetes, high blood pressure, heart disease or a family history of kidney disease and plan a high-protein diet, so you can get your kidneys checked first.
Two reviews of randomized trials, with 28 and 22 trials, found no sign of kidney damage from high-protein diets in adults without kidney disease. Confidence is moderate because most trials lasted months rather than years and used blood tests that only estimate kidney function.
High-protein diets have not been found to damage healthy kidneys in randomized trials. Across 22 trials in adults without kidney disease, high-protein diets raised kidney filtration a little but did not change creatinine, a blood marker of kidney function, and an earlier review of 28 trials found no difference in how kidney function changed over time.
Eating more protein makes the kidneys filter more, which shows up as higher filtration estimates on blood tests; the newest trial review says this most likely reflects a short-term adjustment, not injury. One long-term Korean study of about 9,000 adults linked the highest protein intake with a faster drop in kidney filtration, but studies like that cannot show cause and effect, and the randomized trials have not shown harm.
- Teixeira Silva PR, Santos P, de Miranda Silva Nogueira PA, Nogueira IDB, Vieira RP, Nascimento MF, Tuesta M, Sá Filho AS, Chiappa GR. 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. Diabetes, Obesity and Metabolism. 2026;28(9):7672-7683. DOI: 10.1111/dom.70996. PMID: 42289790. PMCID: PMC13449083
- Devries MC, Sithamparapillai A, Brimble KS, Banfield L, Morton RW, Phillips SM. Changes in Kidney Function Do Not Differ between Healthy Adults Consuming Higher- Compared with Lower- or Normal-Protein Diets: A Systematic Review and Meta-Analysis. Journal of Nutrition. 2018;148(11):1760-1775. DOI: 10.1093/jn/nxy197. PMID: 30383278. PMCID: PMC6236074
- Jhee JH, Kee YK, Park S, Kim H, Park JT, Han SH, Kang SW, Yoo TH. High-protein diet with renal hyperfiltration is associated with rapid decline rate of renal function: a community-based prospective cohort study. Nephrology Dialysis Transplantation. 2020;35(1):98-106. DOI: 10.1093/ndt/gfz115. PMID: 31172186
- National Institute of Diabetes and Digestive and Kidney Diseases. What Is Chronic Kidney Disease? Last reviewed February 2025
- Ikizler TA, Burrowes JD, Byham-Gray LD, et al. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update. American Journal of Kidney Diseases. 2020;76(3 Suppl 1):S1-S107. DOI: 10.1053/j.ajkd.2020.05.006. PMID: 32829751