Protein is everywhere right now. Shakes, bars, extra chicken on the plate, and a quiet worry in the background that it might be hard on your kidneys. For a lot of people trying to eat better, that fear is the main reason they hold back on protein-rich meals.
That fear now has even less backing. A June 2026 meta-analysis in Diabetes, Obesity and Metabolism pooled 22 randomized trials of adults without kidney disease. High-protein diets did not harm kidney function, and kidney filtration actually ticked up.
The pattern is not new. An earlier review in the Journal of Nutrition from 2018 looked at 28 trials covering more than 1,300 healthy participants and reached the same bottom line. Higher protein did not drag kidney function down.
What the researchers actually measured
The 2026 team only pooled randomized trials, the strongest kind of nutrition evidence. They defined a high-protein diet as roughly 25 to 35 percent of daily calories from protein, or at least 2 grams per kilogram of body weight each day.
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For a 70-kilogram adult, that works out to about 140 grams of protein daily. That is well above what the average person eats.
The main outcome was estimated glomerular filtration rate, or eGFR. It is the number doctors use to track how well your kidneys clear waste from the blood. In the pooled trials, eGFR rose on high-protein diets instead of falling.
Serum creatinine, another standard marker of kidney strain, did not budge. The authors concluded there was no consistent sign of kidney injury in people without an existing kidney problem.
They did add an honest caveat. The long-term effects on the kidneys are still uncertain, because most of the trials ran for weeks or months rather than years.
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The researchers also tracked body composition. People on high-protein diets lost body fat on average without losing muscle mass.
The one group that still needs to be careful
Everything above is for healthy adults. For anyone already living with chronic kidney disease, often shortened to CKD, the story flips.
According to the NIDDK, part of the US National Institutes of Health, people with CKD may need to eat only moderate amounts of protein so waste does not build up in the blood.
The institute recommends working with a doctor or registered dietitian to find the right amount, because too little protein can tip into malnutrition on the other side.
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If you have symptoms like swelling in your legs, foam in your urine, or persistent fatigue, that is a conversation to have before you overhaul your plate. Early CKD often shows no symptoms at all, which is why a simple blood test is the only way to really know where you stand.
How much protein you probably actually need
For adults without kidney trouble, the long-standing US recommended daily allowance is 0.8 grams of protein per kilogram of body weight.
For a 70-kilogram adult, that is about 56 grams a day, roughly what you get from two chicken breasts. For a 90-kilogram adult, about 72 grams.
Many nutrition researchers now argue that older adults and people doing serious resistance training benefit from more than that baseline, because the body uses protein less efficiently with age. The new meta-analysis fits with that direction.
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It suggests that eating well above the RDA, up to around 2 grams per kilogram, does not punish the kidneys of a healthy adult.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.