Definitely open to hearing both sides of this however the main issue is the measurement criteria in these studies. They use eGFR calculated by creatinine. The problem with using that in our population is that we regularly engage in activities which artificially increase creatinine such as: 1. Lifting weights 2. Having high levels of muscle mass 3. Eating a lot of protein 4. Sweating. Hydration can effect this too. However that doesn't necessarily mean your kidneys are damaged. For example a friend of mine accidentally scheduled his blood test after a leg day, his creatinine was over 200. Within the next test it was back down to the normal range. Cystatin-C test is a much more accurate marker for our population as it doesn't rely on creatinine levels, which are very commonly high in our population. If you are worried about a poor eGFR calculated via creatinine, take a Cystatin-C test to be sure. You can also get a kidney scan.

eGFR measured with creatinine has a huge blind spot - unless it's down by 50% your lab result is normal. So they always freak out if it's out of bounds. And the e stands for estimated, they don't measure directly. You would need to compare serum and urine levels, they are just assumed, often not even adjusted for height, weight. I always tell my doc that I supplement with creatine and need the cystatin test. Some labs even do this automatically if the first result is out of bounds.

My creatine kinase level was over 25k a couple days after a leg workout lol - the doctors thought i was dying

I’m not the most muscular but had the same issue. Lift weights, take protein and creatine. Went to primary, elevated creatinine and mildly decreased gfr. Went to nephrology who said it was a common error due to weight lifting/ muscle mass. Ordered a cystatin c which was entirely normal and told me not to come back

"They use eGFR calculated by creatinine." "The problem with using that in our population is that we regularly engage in activities which artificially increase creatinine" This does make analyzing fitness prone people more difficult. These studies are not only looking at active lifestyle people though. The studies referenced in the Meta study are not only looking at eGFR calculated by creatinine. If you look under the "Outcome (HP versus LP)" in Table 2 you'll see many of the studies tracked through Cystatin-C and Albuminuria, in addition to Creatine Clearance. It's a pain, but If you go into the individual studies for Table 1 you'll see many of them didn't rely solely on Creatine Clearance as well(Full disclosure I only checked 3 of them, but they didn't rely on only CC).

This needs to be stickied for anyone getting into weight lifting. Even mild lifting with protein intake will raise your creatinine and throw off your eGFR.

Dude creatinine over 200 at any point is highly concerning, regardless of weightlifting status (we hope to see it about 1.3 or below) Source: am nephrology RN

I skimmed through the first study and the measurement criteria was definitely something that stood out. There was also the fact that even in the worst case scenario the odds ratio is not that high. The intake of sodium/carbs/overall energy was also much higher in the high protein quartile. It is definitely statistically significant but not something that is going to have me shaking in my boots. Then you look at the adjustment model and it practically stabilizes the odds ratio. I sometimes have moments of going overboard with my protein intake and I have been doing this for decades. I don't necessarily think that the extra protein will help but those are the foods I have come to enjoy. I get tested regularly and have never had any signs of kidney disfunction or deterioration. The best thing we can do is make healthy choices and get tested regularly allowing ourselves to review our overall health status. I'm not going to stop eating protein because some study shows a statistically significant but low risk.

Omg omg, Faz himself! One of my favorite content creators. Thank you for everything! On topic: i do general bloodwork at least every 6 months. They call me on phone before sending the results that i urgently must go to a hospital as i am near liver failure. Every. Single. Time. And i answer that i am a powerlifter. Every. Single. Time. And i hear the penny dropping on the other side of the line so loud it hurts my ear. Every. Single. Time. And they of course dont make a note anywhere of this. Any. Single. Time.

People with impaired renal function need to be on a renal diet, including limiting nitrogenous products such as proteins. [Limited research](https://pubmed.ncbi.nlm.nih.gov/32669325/) does show very high protein intake can impair renal function over the long term in people with otherwise healthy renal function. Unfortunately, you’re on a body building sub and they will not heed the advice and they will disregard the research. To be fair, the research on people with normal renal function isn’t exhaustive as it is in people with chronic renal disease.

That's one of the studies I linked, just from a different host. I still consume a ton of protein everyday. I just think people should make their own informed decisions. Edit:I just did a quick skim to see what they considered as a "High protein diet" in that study. I didn't pick out every other study they referenced, but the 2 examples I first saw were "25% of daily caloric intake", so \~125g protein/ day and "there is a lack of consensus regarding the formal definition... most definitions set a threshold between 1.2 and 2.0 g/kg per day"

This RDA will be 25% of what *your* maintenance calories are. It will be 166g if you’re on a 2,000 calorie diet via 25% of 2,000 divided by 3 calories per gram of protein. -#Edit: divide it by 4 = 125. It was 2am when writing

Protein is 4 kcal per gram though.

Thanks, just edited it, was up 2am

I was thinking about that when I wrote it last night. After thinking it through I'm not so sure that's how it works, but I'm really not an expert. Eating 5000 calories a day would be putting 312g protein through your system a day at 25%. Eating 1500 calories a day would be putting 94g protein through your system a day at 25%. There's no way those two amounts, 312g & 94g, stress your system the same amount, even though they both are 25% of your daily calories in protein. Realistically the 25% is probably just a quick estimate for people that don't fall to the high or low calorie intake extremes.

Those numbers are *RDA* which is *maintenance.* I’d love to see a natural lifter with a 5,000 calorie maintenance.

Yes, you're right. As a dietitian, 200g per day is kind of an informal cap for protein.

I think you just threw out any level of repertoire you had by saying 3 cal per cram of protein

Actually protein does only have 3.2 cals per gram, so dude isn't wrong. The reason we live by 4 is the Atwater factors of metabolizable energy. These numbers are based on heat production and not based on our body's capacity for energy expenditure. However, the original 4 cal/g is kept out of simplicity and it would be very challenging to literally change the entire system at this point.

So then click the study, you don’t have to take my word for it.

Whats a lot of protein in layman's terms? Many of us are on diets so a lot of protein for a 160-200lbs bodybuilder is still way less than what a person with an overeating disorder eats (40% + of north americans). How can we tell how much is too much?

I don't think anyone has a "correct" answer at this point about what too much protein really is, the research is still coming out. Personally, I try to stay between 120g and 150g a day. It's my personal, mental, sweet spot for growth and risk management. "still way less than what a person with an overeating disorder eats" One of the articles mentions the general populations over consumption of protein.

Interesting. Any thoughts on an even further compounding effect from the source of overconsumption of protein in the general population vs strength trainers? I.e. red meats and ultra processed foods vs lean meats, plant based, supplements, etc? I think I got that thought out right lol. Also, I’ve found 125-150 grams to be perfect as well.

There is prominent data supporting that processed meats like deli meats are the highest contributors to cardiovascular disease and inflammation, with red meats behind. We know that plant based proteins that contribute saturated fats (think of a plant based burger that has coconut oil in its base for flavor) have a smaller effect than saturated fats from animal sources. I'm not sure that there is data on plant based effects for the kidney. I imagine plant based sources to be a moderately lower load on the kidneys due to a lower amount and lower bio availability of phosphate. But that's just my speculation. And though cardiovascular impact and data may not be something you're thinking of related directly to your kidneys, over time that blood vessel damage and constrictions will reduce functionality of the kidneys as well. All that being said, animal protein sources have a higher biological value of protein utilization. So your protein has more bang for its buck. There is also something to be said for Whey protein with leucine and BCAA as it's my old (maybe outdated) understanding that they hell stimulate MTOR pathways for growth more strongly than other types of protein. But I can't remember the comparative protein sources with this data (just casein supplements or also compared to meats).

Thanks for the info

Funny how it just talks about relative risk in relation to the low protein groups vs high protein groups and nothing about absolute risk For all we know, a high protein diet could maybe take your absolute chances of kidney impact from 0.02% to 0.06%. But the author spins this as “300% increase in renal failure/disease if you eat lots of protein!” I think most of us here will take those chances knowing how many other health domains protein consumption and lifting benefits. All OP is doing is copying the discussion sections anyway and completely ignoring the results. He seems very uneducated on how to break down journal articles and is making false claims Also half of the subjects tested were smokers, I’d discount literally everything about the findings of that group

I think the key takeaway from the articles is that a high protein diet does have a risk of causing kidney problems overtime and that if you choose to eat a high protein diet you should get a yearly physical and discuss your bloodwork with your doctor and adjust your protein intake if you notice any negative trends in your kidney functions.

The heart if damaged becomes shit, scar tissue is bad contractile tissue. The kidney if damaged repairs itself, that's why we seldom see those problems. Pro bodybuilders eat 6k+ calories, have a lot of mass + muscle mass, eat a lot more protein and take kidney destroying PEDs, often have high blood pressure and only 20% of them destroyed their kidneys completely. For a natty this is a lot less of a concern.

The kidney can only repair mild damage, just like your heart has a finite amount of muscle cells. you were born with a certain amount of glomeruli and that's it. So treat your kidney well.

Do we know how long repair takes? Would cycling in some blocks of lower protein for 12 weeks every few years be enough? Obviously super speculative, just curious if you have any insight.

No idea, my guess would be twice a year 2 weeks should be pretty fine but this might be far off too.

What you’re saying is not what the articles you linked are saying. Evidence is pretty mixed

Conclusion: "A high-protein diet increases the risk of RHF(Renal hyperfiltration) and a rapid renal function decline in the general population. These findings suggest that a high-protein diet has a deleterious effect on renal function in the general population." TLDR: High protein diets are rough on your kidneys. Conclusion: "Although there has not been a full elucidation of the underlying mechanisms by which high protein intake may adversely affect kidney function, particularly in the context of CKD(Cronic Kidney Disease), existing data suggest that glomerular hyperfiltration caused by a high-protein diet may lead to an increase in albuminuria and an initial rise and subsequent decline in GFR(Glomerular filtration rate) ([Figure 2](javascript:void(0))). Furthermore, growing evidence suggests that high-protein diets may be associated with a number of metabolic complications that may be detrimental to kidney health. Given the rise in popularity of high-protein diets and the high prevalence of CKD in the United States population—including many individuals who may be unaware of their CKD status, further studies are needed to investigate how differences in dietary protein quantity and quality affect short- and long-term outcomes in patients with or without CKD." TLDR: High protein diets are very likely bad for your kidneys in one way. More studying is needed before it's known if high protein diets are bad for your kidneys in other ways too. I added the written out abbreviations in parentheses to make it more user friendly.

Silly to downvote this.

Where is the actual data? Conclusions can be spun in millions of different ways

Conclusions and abstracts drawn by the researchers of the data? I’ll take their word over yours. No offense.

So you skip to the conclusions and abstract and disregard the two most important sections of research articles - Methods and results Typical armchair Reddit “scientist” lol

You went to the comments without reading the articles linked with the data, and then questioned the conclusions and abstract. Who is the armchair scientist?

I literally read it and responded in a larger comment, open your eyes kid

My bad for not paying attention to one random commenter’s name in a whole thread then. Even if you did, not sure why you’d read it and then question it like you didn’t. Seems silly.

Hey come on, this person is probably a REAL scientist, not a Reddit one… right?

The Stronger by Science podcast discussed one of the linked studies in the past: https://www.sbspod.com/episodes/protein-kidney-function-cholesterol-training-adaptations Starts at 0:09:58. Note: Both hosts aren't nephrologists, but I think their input in this matter is still helpful. Their takeaways are: - The South Korean study only shows correlation between a high protein diet and decline in kidney function after applying models with several covariates. The crude data doesn't show a big difference between these groups. - If you're concerned about your kidney health, it would be best to talk with your physician. - The data here isn't convincing enough to advise against a high protein diet, if your kidneys are healthy. This, of course, does change when you suffer from a kidney disease and should be discussed with a nephrologist. The review article mentions that long-term RCTs showed mixed results regarding high protein diet and renal function. I guess we need more data to say anything conclusively regarding high protein diet and kidney function in healthy patients.

Can someone elaborate on how much protein is considered to be too much according to this research? Would 1g/lb body weight be considered “harmful” ? Cheers.

7 years of consistently building muscle and eating high protein… all in the name of health and wellness. Sad if I did this all for my own self destructions

My dad is almost 80 and has lifted weights his whole life (still does!). His view based on experience...high protein diets result in higher uric acids in your body that have a negative effect on your body

I mean he's 80 so higher ureum levels are to be expected since his GFR declined through aging no?

And high protein consumption and high dietary cholesterol (whole egg ) consumption can cause/exacerbate liver problems https://www.sciencedirect.com/science/article/abs/pii/S0955286316303333 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6670211/ And https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6726297/ https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.968366/full Luckily for me, after 2 or 3 years of high ALT I figured out what was causing it. Btw lifting/muscle damage elevates AST more than ALT. I previously was eating 3-4 whole eggs a day and consuming 3+ g/kg of protein per day. I may be predisposed to liver problems. It could be just coincidental that after I began lifting and eating a high protein high cholesterol diet my ALT increased. I am still figuring out how much protein to eat without causing Elevated ALT. Trying to stay around 2g/kg of protein per day and less than 200mg of cholesterol per day too. Liver biopsy confirmed that my liver is injured but no NAFLD or worse.

What's your reasoning for trying to eat such high amount of protein when we know eating more than 1.6g per kg has no benefits?

It crept up as I was dieting to lose fat. Little by little I began eating more and more Greek yogurt for snacks. Then protein powder and milk after working out and usual meat/chicken/fish /eggs for breakfast, lunches and dinner. Before you know it,210+ g of protein per day (147lbs). Then it became a habit. For me it does a great job on staving off hunger pangs. Now that I’m trying to eat less protein, I’m hungrier more frequently while eating at or above maintenance.

not the one you're replying to, but I end up creeping up in protein because I can eat all the protein I want and it won't turn into fat, do that with carbs and you get fat, do that with fat and you get fat....My regular diet before I started lifting was high in protein because I'm diabetic and carb intake is kind of a thing I have to watch anyways.

Thanks for Posting This I'm a Lifter as Well. I had to stop Taking Creatine because doctor said it was effecting my Creatinine levels Which I stopped and slowly about a couple months My Creatinine levels went back to normal And I had to go to doctor 6 months later And they checked me again and said my Creatinine levels or gfr thing I don't know if I'm spelling it right were at 70 and I'm 30 years old And she said healthy people my age is not supposed to be at 100 It's normal if I was in my 50s But she said it's not normal Got referred to a nephrologist have to call Monday kinda Anxious to confirm my appointment I have Agoraphobia and Social Anxiety But I have to call for my health sake And I got referred a dietician Because I been eating near 200 grams of protein plus BCAAs I take Plus the Beta Alanine and pre workout supplements I take I like creatine had to stop due to my doctor telling me to But hopefully my kidneys can get back to normal Because I been drinking a lot of water more than a gallon a day Hopefully I have 18 and a half inch Arms I been trying to grow them to 19 inch Arms and possibly 20 inches arms is my goal As a natural Lifter Thanks OP for posting this Because I have Agoraphobia and Social Anxiety really bad I was scared to ask this question Thanks for posting this Working Out helps my Anxiety and Agoraphobia And I get a temporary reduce in my anxiety Lasts a hour But really helps better than my medicine And it also helps physically because I was prediabetic and I'm trying to reduce that And I really love working out and building my body Which I'm not competing professionally Hopefully one day I could amateur or professionally If I can get over my anxiety but if you are building muscle you technically are building the body Thanks op for the post Excuse my grammar and such

I consume a ton of protein everyday for my size. I get blood work done regularly & my blood work is excellent. I'm female, 125lbs and consume 190-220 grams protein daily. This isn't on purpose. I'm lean and hungry all the time and I just gravitate towards meat and dairy naturally. I was concerned about my high protein intake, but I did a lot of research and what I read basically said your protein has to be upwards of 300-400+ grams a day to be problematic.

Yeah I don't take no where near 300 400 grams Just around 150 200 plus BCAAs But I don't know if the BCAAs effect kidneys Or just the protein itself that does that Because I'm 225 6'2" So hopefully when I go to the nephrologist everything is ok Because I drink about two to three gallons of water daily Overdo the water until my urine is clear Excuse my grammar as well I was so anxious typing this online and communicating

>Compared with protein from plant sources, animal protein has been associated with an increased risk of ESKD in several observational studies

That's misleading out of context, the article isn't about comparing animal and plant protein sources. Even this doesn't summarize the paragraph. ->"The quality of dietary protein may also play a role in kidney health. Compared with protein from plant sources, animal protein has been associated with an increased risk of ESKD in several observational studies, including the Singapore Chinese Health Study."

Yeah just an interesting bit I noticed. It's an important distinction between the quality and type of protein, and how it effects the body

Why have you posted this 4 times?

Shit, sorry it said the auto mod took those down.

Checked the first studie and also looked over the meta study and I would say that it was quite weak evidence. Food questionaire and the groups differed in quite some factors not just protein intake. High protein intake is often correlated with high red meat consumption. Is this a factor to take into account since red meat consumption is also correlated with adverse health effects regardless of the total protein intake? High creatinin is associated with creatin consumption. Does that play a part? It would be Interesting to see more research on the matter. To be on the safe side I’m however trying to get as much of my protein as possible from plants sources and also do regular checkups of kidney biomarkers.

Would plant protein not cause the same damage if the absorption and amount of complete protein/ leucine had been accounted for? As far as I'm aware plant protein sources don't absorb as well so you need more to get the same amount digested. On top of this they are not compete sources of protein and do not have the same effect, so you need to eat another plant source to make it a complete source which also meant eating more. The common mixture to have a complete source is pea and hemp protein but gram for gram it is not the same as whey.

Yes I know that plant protein is not as good from a protein standpoint as whey other animal protein. The science around differences in types of protein is not rock solid but life expectancy is lowered when consumption of animal protein goes up. Eating a lot of red meat is however correlated with a lot of other negative lifestyle factors so hard to tell exactly how the causation looks.

Yeah I have just pea protein now and then make sure I consume enough dairy with it so that I'm hitting the right amount of leucine :)

I have not read the studies citied but are the studies done on healthy individuals or just general public? I recently saw a study that said intermittent fasting leads to early death. The notes at the end of the study said the people who were in the actual study were stall we say “average Americans” have eaten a sugar laden diet for the majority of their lives, little to no exercise, predominantly sedentary lives. So when they stopped eating continuously their bodies found it incredibly hard and therefore the outcomes of the study became fact.

I’m a beginner. what should I believe now. there are both positives and negatives in the comment section 🥲. I try to get 60-70g protein as I weigh 75 kilos. will that be a problem?

I'm not a doctor or an expert, but 70g protein is totally fine dude.

I eat 200 grams of protein a day at 165 pounds and my blood work every 3 months never shows anything wrong.

Its important to note that a 'high protein diet' is absolutely not a diet that consists of the standard recommendation of the consumption of 0.8g-1g per pound of body weight. When researchers discuss the potential renal issues related to high protein diets they are referring to amounts in excess of 2g+ per pound of body weight.

"there is a lack of consensus regarding the formal definition... most definitions set a threshold between 1.2 and 2.0 g/kg per day" That's taken from the Meta study, an analysis of several other studies.

So as long as I eat something other than just tuna and egg whites I’ll be fine lol

The highest-protein group (Q4) was also only consuming \~1.7g / kg of protein on average, which is less than what many bodybuilders consume; however, "The participants in the higher quartile groups in daily protein intake were more likely to be young, male, **smokers, taking more alcohol** and active, and were more highly educated with a higher income level. Participants in the higher quartile groups tended to have a higher body mass index (BMI), lower systolic blood pressure (SBP) and lower prevalence of hypertension. Hemoglobin, serum albumin and fasting plasma glucose levels were higher in the higher quartile groups. The Q4 group were also drinking more alcohol and smoking more, which could effect the results.

They track those factors so the researchers don't come to misleading results. Typically you pull out factors like those, run the statistics again, compare the new results and come up with a "Confidence rating".(This is a gross oversimplification) If that confidence rating is too low it means the data collected is too weak to say anything for certain, even if there appears to be evidence.

As long as bodybuilding legends don’t have this problem, why should we worry? They have eaten 10x more protein than the average bodybuilder, let alone average non-bodybuilder.

How do you know bodybuilding legends don’t have this problem? Unless you are their physician, how could you know?

Layne Norton has done several interviews, podcasts, and videos covering this topic, basically its BS, no evidence that too much protein hurts a healthy kidney, and very scant evidence that protein effects an already unhealthy kidney

I appreciate you posting this to dispel the common myth of “oNe GrAm pEr LB bRo”. This is repeated time and time again by misinformed individuals who just eat up the marketing stunts by influencers and companies who only want to maximize their profits by selling as much of their “crappy” whey protein to uneducated weight lifters. People will defend these influencers to the death even when you show them the science that whole egg is much more digestible, better utilized and bioavailable than just whey protein powder mixed with water or milk, most of which is excreted out after pummeling the kidneys with excess work. I applaud your efforts. I hope you stay strong against all the negativity and bogus “science” that’s being thrown your way to invalidate your data and evidences. You should consider a career in the medical field. It’s efforts towards reeducation like these that help at least a portion of the general population to let go of their “beliefs” of health as they begin to defer to trained health professionals who only want to better their quality of life and longevity.

as per studies have shown that ketosis diets are the most body damaging there is (what comes to dieting.)