Protein and kidneys: does a lot of protein harm your kidneys?

This is general information, not medical advice. Always discuss your blood values with your doctor.

1. 1

   With healthy kidneys: no harm shown

   A meta-analysis of 28 studies with 1,358 participants (Devries et al., J Nutr 2018) compared higher-protein diets (at least 1.5 g per kilo, at least 20% of energy or at least 100 g a day) with normal or lower intake. It found no adverse effect on kidney function (GFR) in healthy adults. After the intervention, GFR was even slightly higher with high intake, but the change in GFR did not differ between groups. In people with obesity, type 2 diabetes or high blood pressure, the authors also saw no sign of harm.

2. 2

   What sports organisations say

   The International Society of Sports Nutrition position stand (Campbell et al., 2007) states that 1.4 to 2.0 g of protein per kilo per day is safe for people who exercise and may improve training adaptations. In healthy, active people on a varied diet, that intake is not harmful to kidney function or bone metabolism. The recommended dietary allowance (RDA) for adults in general is 0.8 g per kilo. The ISSN considers it inappropriate to extend concerns from research in kidney patients to healthy people with normal kidney function.

3. 3

   If you already have kidney disease, it is different

   In chronic kidney disease (CKD) stages 3 to 5 without dialysis, the 2024 KDIGO guideline suggests 0.8 g of protein per kilo per day and not going above 1.3 g per kilo when there is a risk of progression. The 2020 KDOQI guideline is stricter and advises 0.55 to 0.6 g per kilo in stable CKD stages 3 to 5 without diabetes. So the guidelines differ, and people on dialysis often need more protein. If you have kidney disease, discuss protein with your nephrologist or a dietitian, not with an online calculator.

Updated in October 2026