How much protein is too much, and who sets their own number?
On this page
The US has no upper limit for protein, and in trials healthy kidneys showed no sign of harm from high-protein diets, though most of those trials were short. Above your range, the extra mostly costs calories and money. If you have kidney disease, your doctor sets your number. Pregnancy needs about 71 g a day in the second half.
What we’d do
If your kidneys are healthy, don’t worry about eating at the top of your range or a bit above it. There’s little reason to go far past it unless you’re lean and lifting hard on a diet, since the extra mostly costs calories. If you have kidney disease, or diabetes or high blood pressure and haven’t had your kidneys checked, talk to your doctor before you raise protein. If you’re pregnant or breastfeeding, the US RDA is the reference, and your midwife or doctor sets anything beyond food. This guide is written for adults.
If you remember three things
- No US upper limit has been set. Healthy kidneys filter a bit more on more protein, with no sign of injury in the trials.
- Kidney disease is the exception. Your doctor sets your number, usually lower than this site’s range.
- Pregnancy is about 71 g a day in the second half, 1.1 g per kg, the US RDA.
This page follows the National Academies’ reference intakes, the 2024 KDIGO kidney guideline, the CDC’s 2026 kidney disease figures and the two most recent reviews of protein and kidney function in healthy adults, all checked on November 14, 2026. It doesn’t replace advice from your doctor about your own kidneys.
Why people worry about protein and kidneys
The worry has a real mechanism behind it. When you eat more protein, your kidneys filter more. Doctors call that a higher filtration rate, and in someone whose kidneys are already damaged, working harder can speed the damage up. The question people ask is fair. If more protein makes healthy kidneys work harder, does that wear them out?
Think of a dishwasher that runs an extra load a day. In a new machine that’s fine. In one with a failing pump, the extra loads are a problem. The trials have mostly tested the new machines.
What the kidney trials found
28 studies in healthy adults
1,358 people. Devries and colleagues, Journal of Nutrition, 2018
High protein meant 1.5 g per kg or more, 20% of calories or more, or 100 g a day or more. Kidney filtration ended slightly higher on high protein, and the change in filtration didn’t differ from normal protein. The authors concluded high protein doesn’t harm kidney function in healthy adults.
The authors flagged an unclear risk of bias in how people were picked for the trials.
22 trials, adults without kidney disease
Teixeira Silva and colleagues, Diabetes, Obesity and Metabolism, 2026
High-protein diets (often 25 to 35% of calories, or 2 g per kg or more) raised estimated filtration. Creatinine, the blood marker that rises when kidneys struggle, didn’t change across 19 trials with 1,044 people. No consistent sign of kidney injury.
Most trials were short, and most estimated filtration from creatinine. The long-term effect is still uncertain, the authors wrote.
We’re confident that eating at the top of the typical range, or somewhat above it, is fine for healthy kidneys over months. The trials don’t cover decades, so for very high intakes held for many years, nobody knows for sure.
With kidney disease, your doctor sets it
If you have chronic kidney disease, this site gives you no range. Your doctor or a kidney dietitian sets your number from your kidney function, your other conditions and your weight, and it’s usually lower than the typical range here. The 2024 international kidney guideline (KDIGO) suggests a lower intake for adults with moderate to advanced kidney disease and advises against high protein for anyone at risk of it getting worse. The PROT-AGE expert group, which asks older adults to eat more protein, makes the same exception for people with severe kidney disease who aren’t on dialysis.
Many people don’t know they have it. The CDC says more than 1 in 10 US adults (14%, about 37 million people) have chronic kidney disease, and about 9 in 10 of them don’t know. It’s more common with diabetes or high blood pressure. The CDC estimates about 4 in 10 adults with diabetes and about 1 in 5 with high blood pressure have it. If either applies to you and you haven’t had your kidneys checked recently, ask your doctor before you raise your protein a lot.
The kidney question has more, and the kidney myth covers the healthy side.
How much is too much for everyone else?
The National Academies set no upper limit for protein. Their acceptable range is 10 to 35% of calories, and the report behind the 2026 guidelines repeats that no upper limit has been established.
Above your range, the main cost is calories. Protein has 4 calories per gram.
| Daily protein | At 180 lb | Calories from protein | Share of a 2,000 calorie day |
|---|---|---|---|
| 100 g | 1.2 g per kg | 400 | 20% |
| 130 g | 1.6 g per kg | 520 | 26% |
| 150 g | 1.8 g per kg | 600 | 30% |
| 200 g | 2.4 g per kg | 800 | 40% |
At 200 g, a 180 lb person is well past where gains leveled off in the lifting trials (about 1.6 g per kg), and 800 calories of their day is going to protein. That’s expensive, and it crowds out vegetables, fruit and whole grains. It isn’t dangerous for healthy kidneys on the evidence so far.
The is my number enough? calculator places any daily number on your range and shows what it costs in calories.
Pregnancy and breastfeeding
| US RDA | A day | |
|---|---|---|
| First half of pregnancy | Same as before pregnancy, 0.8 g per kg | 46 g at the reference weight |
| Second half of pregnancy | 1.1 g per kg | 71 g |
| Breastfeeding | 1.3 g per kg | 71 g |
The National Academies set the higher number “only for the second half of pregnancy”. For the first half, needs are the same as before.
Some researchers think the RDA is too low. In a 2015 study of 29 healthy pregnant women in Canada, the average need came out at about 1.22 g per kg early in pregnancy and 1.52 late. Those are average needs measured by a lab method, not recommended intakes, and they haven’t changed the RDA. If you’re pregnant, eat protein at every meal from the foods you’d normally eat, and let your midwife or doctor set anything beyond food, like a supplement or a powder. Our pregnancy guide covers the foods to skip, fish and B12.
Under 18
This guide is written for adults. Teenagers’ needs are set by age in the US reference tables, and the ranges and calculators on this site aren’t built for them. A teenager who lifts or plays sports and wants more protein is best served by more real food at meals, and their doctor is the person to ask about powders.
The case for an upper limit
Some groups do warn against very high intakes. The 2025 advisory on nutrition with GLP-1 drugs says protein intake held above 2 g per kg a day for a long time should be avoided because of possible adverse health effects.
That’s a reasonable caution, and it fits what we’d recommend anyway. The typical range tops out at 1.6 g per kg, and only lean people lifting hard on a diet go higher, counted from lean mass. The kidney trials found no injury in healthy adults, but they don’t cover decades, so there’s no reason to push far past what your muscle can use.
Who sets their own number
| If you | Your number comes from |
|---|---|
| Have chronic kidney disease | Your doctor or kidney dietitian. This site gives no range |
| Have diabetes or high blood pressure and no recent kidney check | A kidney check first, then your range |
| Are pregnant or breastfeeding | The US RDA, with your midwife or doctor |
| Are under 18 | The US reference tables by age, with your doctor |
| Are on a GLP-1 drug | The same range, with your prescriber for anything about the drug |
| Are healthy and over 18 | Your daily range. The Gyroscope app personalizes yours |
12 sources
- National Academies, Dietary Reference Intakes: Recommended Dietary Allowances and Adequate Intakes, total water and macronutrientsnationalacademies.org
- Health Canada, Dietary Reference Intakes tables, reference values for macronutrients (Institute of Medicine, 2005)canada.ca
- Scientific Foundation for the Dietary Guidelines for Americans, 2025 to 2030cdn.realfood.gov
- Devries et al., 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, 2018pubmed.ncbi.nlm.nih.gov
- Teixeira Silva et al., 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, 2026pubmed.ncbi.nlm.nih.gov
- Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group, KDIGO 2024 clinical practice guideline for the evaluation and management of chronic kidney disease, Kidney International, 2024kdigo.org
- Bauer et al., Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group, Journal of the American Medical Directors Association, 2013pubmed.ncbi.nlm.nih.gov
- CDC, Chronic kidney disease in the United States, 2026cdc.gov
- Mozaffarian et al., Nutritional priorities to support GLP-1 therapy for obesity: a joint advisory, Obesity Pillars, 2025pmc.ncbi.nlm.nih.gov
- Stephens et al., Protein requirements of healthy pregnant women during early and late gestation are higher than current recommendations, Journal of Nutrition, 2015pubmed.ncbi.nlm.nih.gov
- Morton et al., A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults, British Journal of Sports Medicine, 2018pmc.ncbi.nlm.nih.gov
- USDA National Agricultural Library, Food and Nutrition Information Centernal.usda.gov
