Please Scroll Down to See Forums Below I was wondering, exactly why if someone doesn't consume 1,5-2,0 grams/lb. of protein, protein every two hours etc. will lose muscle. If the body is never on catabolic state by eating any macronutrient, surely the body will not switch to protein for energy. Also, since the body can build only very, very small amounts of new muscle every day, protein needs can't be so incredibly high for that. Does anyone have a link for a proper scientific study, not sponsored by supplements manifacturers that proves that someone needs so much protein to maintain/grow?
Protein intake question
- Thread starter Jeus
- Start date
diamonddiceclay
New member
there is no scientific study showing how much protein can be used by the body at 1 time, however there are many studies on bodybuilders showing they need more protein than non bb'ers in order to build muscle-it may be 1.5 or 2 or whatever-the point is the more protein you take in, the better your results will be in muscle building
Can someone point me to a study that proves that 'the bigger the protein intake of a body builder, the better results in muscle building'?. Surely, body builders need a better and more balanced diet than coach potatoes, hoewever, someone not lifting can very well live with minimal protein intake, why is it that someone who lifts needs vast amounts of protein?
riskybizz007
New member
you wont find the study. Do yourself a favor, try it yourself. Go on a protein restricted diet 1 time, then try the 1.5-2.0/pound of body weight diet and see which would yield the better results. I've tried both and the 1-2g/pound of body weight works a hell of a lot better.
Ok, you obviously think that this is some sort of supplement company conspiracy. Fair enough. There's certainly a lot of garbage that those companies advance. However, huge supplement companies have only been around for 20 years or so, I think. Well, why did all of the bodybuilders prior to that and prior to the advertising hype still consume so much protein? Food for thought.
Jeus said:
you need a certain amount of protein as you need other things for optimal exercise, but taking excessive amounts of protein does not directly affect your muscle mass. this is a nutrition myth.
you need about .8-1.0 grams of protein for evey kilogram you weigh.
in addition, too much protein does turn into fat.
Blood&Iron
New member
Arnold at least in his Encyclopedia, which as I've stated before, may or may not reflect his actual practices states he came to the conclusion that the vast amounts of protein he consumed in his early years of bodybuilding were not needed. Don't remember the amount he recommends to consume but it is fairly moderate(120g or so for a 200 lbs bodybuilder. I think)Grizzly said:
Jeus-
The only studies of which I am indirectly aware have used protein levels of about 1-1.5 g per kg of lean mass. Look on medline if your really interested or search around on the web.
1-1,5 grams per kgr. of lean mass is a more logical amount.
Cure-if you are eating maintenance level calories, any macronutrient will do. Assuming you get sufficient protein, the amount of which has not been backed up from anyone pro-mega protein intake in this thread so far, anything will do as you're not going to make gains on muscle or fat anyway. Same goes for bulking or dieting. If your body can use x grams of protein while bulking to build new muscle, anything more will be stored as fat regardless if it somes from extra protein, carbs or fat. Same logic stand for dieting.
Cure-if you are eating maintenance level calories, any macronutrient will do. Assuming you get sufficient protein, the amount of which has not been backed up from anyone pro-mega protein intake in this thread so far, anything will do as you're not going to make gains on muscle or fat anyway. Same goes for bulking or dieting. If your body can use x grams of protein while bulking to build new muscle, anything more will be stored as fat regardless if it somes from extra protein, carbs or fat. Same logic stand for dieting.
Blood&Iron said:
When I get back into my own house, I'll have to look in the Encyclopoedia, but I don't remember that passage at all. In fact, I can specifically remember the phrase "1 gram per pound of bodyweight." How about in "Blood and Guts", Dorian Yates' book? He states that one should begin with a minimum of 1 gram/lb and work up from there.
So what? We're talking about two completely illiterate people who couldn't even complete a sentence in English, juiced extensively and were probably sponsored by sup. comps. I can't believe there's no scientific data whatsoever, yet eveyone's quite happy to blindly accept it. I'm sorry, I can't accept anyone's trial and error. I spent a couple of hours searching the net and every *study* I found claiming one should consume such huge amounts of protein everyday was indeed sponsored by supplements companies.
Cure said:
i just wanted to note something.
It doesn't matter where you get your calories from in terms of weight loss, whether it be protein, fat, carbs etc. A calorie is a calorie. The point is to not to exceed taking more calories than you expend.
As a matter of fact more carbs might be better for exercise than protein.
Blood&Iron
New member
Took a look myself. We're both right in this instance. Arnold, or Bill Dobbin's,--who's to know who's words we're reading--states that many nutritionists suggest that no more than 1g per kg of protein is needed for bodybuilding(This is in bold) but that he thinks 1/g per lb is better(Also in bold). He says to use these as lower and upper bounds, respectively. This is still a fairly moderate intake IMO, and his sample diets fall in between these two figures in the amount of protein(He grossly overestimates the amount of protein in the protein sources listed in his meals though.)Grizzly said:
Blood&Iron said:
Well, I'd imagine that they're Arnold's words. Maybe it's just because I want them to be, but I would hypothesize that Arnold dictated most of it and Bill just typed it up and put it in better wording. I would agree that it is a moderate intake. I know I take in closer to 2 grams/lb, but I would definitely say that you should eat no less than .8 grams/lb. And, really, 1 gram/lb is freaking easy to get. For most people that's about 170-200 grams. Piece of cake. Couple cans of tuna, couple chicken boobs, a dozen egg whites and a scoop or two of protein powder. Hardly seems too exorbitant to me.
And, look at that, I've almost completely eliminated the supplement company from the equation. Look at that! High protein and no supplements needed, or moderate. Even with my 400-500 grams/day I only use 3 scoops of protein powder. I spend about $50 per month on powder. Hardly seems like a conspiracy to me.
Blood&Iron
New member
Hell, I was never one to say it was a conspiracy. There is simply a lack of evidence it is necessary. Despite that I usually get anywhere from 250g to 400g of protein a day, depending on whether I'm bulking or dieting. I'd rather error on the side of overconsumption than underconsumption.Grizzly said:
FitnessFrk
New member
I would bet the bank that Arnold wrote very little if any of the content in any of his books.
Blood&Iron said:
Oh, the conspiracy thing wasn't aimed at you. It was aimed at eveyone else who seems to think that there is some sort of conspiracy. I could almost kiss you for that last part. That's what I say, too. It's always better to get too much protein than too little, so even if 400 is overkill it's better just because your body is certain to get, at least, enough protein.
Blood&Iron
New member
No, it can't. There is absolutely no evidence that in those without preexisting hepatic or renal dysfunction the overconsumption of protein will cause any sort of problem.chaste said:
Jeus, as far as I know, the only reason to eat LOTS of protein is as 'insurance'. Kinda like taking a multi-vitamin even though in theory you're getting enough vitamins from your diet. The vast majority of bodybuilders take in grossly more protein than they need. But protein can be converted to carbs or fat if the body is in short supply. The reverse is not true. Neither carbs nor fat can be converted to protein, so it is better to err on the side of too much protein.
Now here's some food for thought.....you only need around 200 grams of extra protein to add a pound of muscle. So an excess of a mere 25 grams per day above what you burn and excrete is theoretically enough to add a pound of muscle per week. However the body is not a perfect machine, and the balance, timing and absorption/deposition of protein is critical. If your a little short of even one minor amino acid, or if you eat a lot of fiber (which reduces protein absorption from the gut), or if all the aminos are not at the muscle cell at the exact moment everything else is anabolic, if vitamins/minerals are not optimal, etc.... then that protein will be used for other things, or excreted. You will find no hard science that will tell you exactly how much protein you need to eat each day. It will change from day to day, and person to person. The best thing you can do is eat enough and then a little extra!
I think the jury is still out on liver and kidney damage. Short and medium term studies support the safety of high protein diets, but if you eat like that for 80 years straight, well no one can say. The main cause of death in old cats (who are nearly perfect carnivores) is kidney failure, and that's after only 12-16 years on average. Now humans are not cats, but it's just something to consider.
Personally I eat high protein when I'm dieting (carbs are restricted) and moderate protein the rest of the time. I find it cheaper and more palatable to burn carbs and fat for my fuel, and leave the protein free for maintenance and muscle building.
Now here's some food for thought.....you only need around 200 grams of extra protein to add a pound of muscle. So an excess of a mere 25 grams per day above what you burn and excrete is theoretically enough to add a pound of muscle per week. However the body is not a perfect machine, and the balance, timing and absorption/deposition of protein is critical. If your a little short of even one minor amino acid, or if you eat a lot of fiber (which reduces protein absorption from the gut), or if all the aminos are not at the muscle cell at the exact moment everything else is anabolic, if vitamins/minerals are not optimal, etc.... then that protein will be used for other things, or excreted. You will find no hard science that will tell you exactly how much protein you need to eat each day. It will change from day to day, and person to person. The best thing you can do is eat enough and then a little extra!
I think the jury is still out on liver and kidney damage. Short and medium term studies support the safety of high protein diets, but if you eat like that for 80 years straight, well no one can say. The main cause of death in old cats (who are nearly perfect carnivores) is kidney failure, and that's after only 12-16 years on average. Now humans are not cats, but it's just something to consider.
Personally I eat high protein when I'm dieting (carbs are restricted) and moderate protein the rest of the time. I find it cheaper and more palatable to burn carbs and fat for my fuel, and leave the protein free for maintenance and muscle building.
Stryc-9
New member
Another thing to consider regarding this debate (as if there weren't enough variables already!!) is the fundamental difference between the amount of protein you put INTO your body and the amount of protein that your body ACTUALLY absorbs....
...just because you drink a shake with 30g of protein - doesn't necessarily mean that your body will metabolize and make use of 30g of protein....there are a myriad of factors that will influence the rate and degree of absorption....
...I guess I would consider this yet another reason to err on the side of "too much" protein - rather than "not enough"....
...just because you drink a shake with 30g of protein - doesn't necessarily mean that your body will metabolize and make use of 30g of protein....there are a myriad of factors that will influence the rate and degree of absorption....
...I guess I would consider this yet another reason to err on the side of "too much" protein - rather than "not enough"....
Blood&Iron
New member
I, for one, don't plan on eating super high protein for the next 80 years. I will only do so until I've reached my final physique goals, which I think will happen in the next 2-3 years. After that I'll drop the amount considerably and I very much doubt 200-250g a day will cause damage in the long term, and it is certainly sufficient to maintain the 235 or so I plan to weigh. I would also venture that relative to their body weight cats still eat far more protein than even the most extreme bodybuilders I would guess for a human this would be akin to a 200lb person eating somewhere in the vicinity of 800g of protein a day(Of course this is pure conjecture on my part.)MS said:
My End Over Mad her
New member
I was wondering, exactly why if someone doesn't consume 1,5-2,0 grams/lb. of protein, protein every two hours etc. will lose muscle - Jeus
This question I don't think became answered, if it did please bare with me, but I was curious as well as Jeus when exactly will muscle become burned for energy? If i don't eat every 2 hours or 3 hours will it resort to using muscle?
This question I don't think became answered, if it did please bare with me, but I was curious as well as Jeus when exactly will muscle become burned for energy? If i don't eat every 2 hours or 3 hours will it resort to using muscle?
My End Over Mad her said:
I don't think it's so much to prevent the body from starting to eat away at muscle, although, when not consuming enough food frequently enough your body will become catabolic. I think the main reason is so that the body has enough readily available amino acids to assimilate new muscle tissue.
Stryc-9 said:
everybody made some good points,
regarding this quote, depending on what you are referring to ...
how much protein you put INTO your body equates the amount that is ACTUALLY absorbed.
Because regardless, all the Protein you take still has to pass through the kidneys and the kidneys have to decide what to do with it. so essentially your kidneys have to deal with whatever amount of Protein you take in.
the kidneys can become overburdened by too much protein simple and plain.
now also dont get me wrong, the body can take a large amount of protein certainly, we're talking about very excessive amounts. I would speak with a real physiologist if you think that you need to take 600+ grams.
sometimes weight lifters don't take into account real science, because they are only concentrating that whatever they are doing is working for them, but I am talking about real health not whether you have larger biceps then the next guy due to excessive protein or whatever else.
If you mean the difference between intake and how much the Muscles actually absorb then I see the point
My End Over Mad her
New member
So ultimately if you eat every 2-3 hours or whatever, its the nutrients that are used instead of muscle tissue, so as long as you are eating carbs or fat you shouldn't not be burning muscle,
and in an anabolic state. So as long as you get your protein requirements for the day you should be fine wether you eat it in one meal or spread out over meals.. is the only benefit from spreading out insurance that you can assimilate the right amount?
i would think that consuming all of it in one sitting wouldn't be optimal since you want to keep feeding your muscles throughout the day, naturally. But, I'm still wondering if IT is that much better every 2-3 hours instead of every 5 hours even if you meet your requirements in the fewer meals...
and in an anabolic state. So as long as you get your protein requirements for the day you should be fine wether you eat it in one meal or spread out over meals.. is the only benefit from spreading out insurance that you can assimilate the right amount?
i would think that consuming all of it in one sitting wouldn't be optimal since you want to keep feeding your muscles throughout the day, naturally. But, I'm still wondering if IT is that much better every 2-3 hours instead of every 5 hours even if you meet your requirements in the fewer meals...
Hoffmeister
New member
I think most of the studies indicate 1.2-1.8 grams of protein/kg of bodyweight. The high end is usually just rounded to 1 g/lbs of bodyweight. Here's at least one of the studies:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1474076&dopt=Abstract
One thing I believe these studies assume is that energy requirements are being met. But here's one that showed positive nitrogen balance even on a hypocaloric diet at 1.6 g/kg:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3182156&dopt=Abstract
It's pretty safe to say that 1-1.5 g/lbs is sufficient. Will eating massively higher amounts work? No doubt, but you'll just be using the protein as a fairly expensive source of "carbs".
As far as eating every 2-3 hours, here's a study comparing digestion rates of protein:
http://www.ncbi.nlm.nih.gov/entrez/...ve&db=PubMed&list_uids=11158939&dopt=Abstract
The casein was still dumping amino acids into the bloodstream 7 hours after eating. So unless you're only drinking whey shakes, I don't think there's any protein related reason to be eating every 2-3 hours.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1474076&dopt=Abstract
One thing I believe these studies assume is that energy requirements are being met. But here's one that showed positive nitrogen balance even on a hypocaloric diet at 1.6 g/kg:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3182156&dopt=Abstract
It's pretty safe to say that 1-1.5 g/lbs is sufficient. Will eating massively higher amounts work? No doubt, but you'll just be using the protein as a fairly expensive source of "carbs".
As far as eating every 2-3 hours, here's a study comparing digestion rates of protein:
http://www.ncbi.nlm.nih.gov/entrez/...ve&db=PubMed&list_uids=11158939&dopt=Abstract
The casein was still dumping amino acids into the bloodstream 7 hours after eating. So unless you're only drinking whey shakes, I don't think there's any protein related reason to be eating every 2-3 hours.
OK, let's use our heads here. Aside from the research which indicates that male bodybuilders MAY need AS MUCH AS 1.8g per kg (but most do fine on 1.2g), there is the question of meal frequency, timing, and absorption.
Chaste, all the protein you put in does not necessarily get absorbed by the gut. That was one of my points. High fiber diets, type of protein, and other nutrients all influence absorption. As much as 10-20% of the protein you put in your mouth will get shat out the other end if digestion is not optimal. So it doesn't all go through the kidneys and liver.
As far as timing and frequency, I have seen no evidience that NOT eating protein every 2 hours will cause your muscles to waste away. This is laughable, and it would mean most people would never gain any mass! Fact is, we're not really talking about catabolism. This is a red herring. Folks that don't use AAS have an absolute requirement for muscle catabolism if they want to gain muscle. You have to break the muscle down and remodel it if you want to grow. The most important things you needs are a stimulus (weight training), rest and adequate protein. Everything else is just extremely fine tuning to get an extra few % out of your training.
The old saying "just do it" is as true now as ever.
Chaste, all the protein you put in does not necessarily get absorbed by the gut. That was one of my points. High fiber diets, type of protein, and other nutrients all influence absorption. As much as 10-20% of the protein you put in your mouth will get shat out the other end if digestion is not optimal. So it doesn't all go through the kidneys and liver.
As far as timing and frequency, I have seen no evidience that NOT eating protein every 2 hours will cause your muscles to waste away. This is laughable, and it would mean most people would never gain any mass! Fact is, we're not really talking about catabolism. This is a red herring. Folks that don't use AAS have an absolute requirement for muscle catabolism if they want to gain muscle. You have to break the muscle down and remodel it if you want to grow. The most important things you needs are a stimulus (weight training), rest and adequate protein. Everything else is just extremely fine tuning to get an extra few % out of your training.
The old saying "just do it" is as true now as ever.
Those of you who deny that excessive amounts of protein consumption can lead to kidney damage--I have a suggestion for you: go to your physician and ask for a referral to have some blood work done. Specifically, ask to have your serum creatinine, BUN, and Albumin tested for in addition to having your Protein Urea tested and maybe have a 24 hr urine creatinine test done.
I used to be as narrow-minded as some of you about my protein intake and refused to believe that I was doing any harm to my body by consuming 250-350g of protein a day (I'm 23 years old, 5'6" and weigh 160lbs) until my serum creatinine level was tested to be what one would expect of a 70 year old man.
Accordingly, I reduced my protein intake and within 4 weeks my creatinine level was back within an acceptable range. After 2 months of eating a considerably reduced protein diet (compared to what I was used to) I have continued to gain muscle mass at the same speed I was before, have not gone into some severe case of atrophy or catabolism and haven't gained any appreciable fat despite an increase in carb and fat consumption to maintain my desired level of calorie intake.
This "if some is good, more must be better" attitude is typical of bodybuilders though. I mean there has to be something in your personality that causes you to obsess and go to extremes if you bodybuild--muscle is good, but more muscle and freakish mass is better. GH is good, but more is better. Protein is good, but more is better.
I used to be as narrow-minded as some of you about my protein intake and refused to believe that I was doing any harm to my body by consuming 250-350g of protein a day (I'm 23 years old, 5'6" and weigh 160lbs) until my serum creatinine level was tested to be what one would expect of a 70 year old man.
Accordingly, I reduced my protein intake and within 4 weeks my creatinine level was back within an acceptable range. After 2 months of eating a considerably reduced protein diet (compared to what I was used to) I have continued to gain muscle mass at the same speed I was before, have not gone into some severe case of atrophy or catabolism and haven't gained any appreciable fat despite an increase in carb and fat consumption to maintain my desired level of calorie intake.
This "if some is good, more must be better" attitude is typical of bodybuilders though. I mean there has to be something in your personality that causes you to obsess and go to extremes if you bodybuild--muscle is good, but more muscle and freakish mass is better. GH is good, but more is better. Protein is good, but more is better.
riskybizz007
New member
I know personally I have grown faster and more muscular when protein intake was above 200mg/day, i weigh 222 currently. Average intake is b/w 200-300mg/day.
About your creatinine levels, if i'm not mistaken creatinine does not show kidney failure or damage it shows dehydration.
Your BUN will show damage to kidneys, and you said nothing about this.
So if your creatinine levels were high or low, if i'm not mistaken here, that would be indicator of overhydration or dehydration, and not an indicator of kidney damage.
About your creatinine levels, if i'm not mistaken creatinine does not show kidney failure or damage it shows dehydration.
Your BUN will show damage to kidneys, and you said nothing about this.
So if your creatinine levels were high or low, if i'm not mistaken here, that would be indicator of overhydration or dehydration, and not an indicator of kidney damage.
Here, I'll help get you started:
http://www.kidney.org/professionals/doqi/guidelines/nut_a05.html
and one more for good measure:
http://my.webmd.com/content/asset/adam_test_creatinine
http://www.kidney.org/professionals/doqi/guidelines/nut_a05.html
and one more for good measure:
http://my.webmd.com/content/asset/adam_test_creatinine
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No disrespect meant NJ, because this IS a controversial subject. but did YOU read those articles?? The first one was referring to people that ALREADY had kidney failure, and the second one clearly states that there are DOZENS of reasons why your creatinine might be elevated (including dehydration).
To date there is no published evidence that a high protein diet produces any negative effect on metabolism in bodybuilders or any other type of athletes.
Recently, a comprehensive study completed by Jacques Poortmans and Oliver Dellalieux (published in Int. J. Sport Nutr. & Exerc. Metab. 11;28-35:2001) at the University of Brussels in Belgium investigated this aspect directly.
These scientists assessed whether high protein diets affect the health and kidney function of bodybuilders and other athletes. Their study involved 20 bodybuilders and 18 other highly trained athletes that consumed a high protein diet. (Approximately 2 grams of protein per kilogram of body weight per day. More than double the recommended daily allowance.)
Their diets were analyzed to provide total calorie, protein, fat, carbohydrate, and calcium intake each day. Blood and urine samples were taken from the athletes and spectrum of analyses were performed looking at glomerular filtration rate (creatinine clearance), potential change in glomerular membrane permeability (albumin excretion rate), urea and uric acid clearance, nitrogen and calcium balances and any modification in kidney free water balance.
In addition to the resting condition, the researchers also wanted to obtain other data that would be important to hard training athletes. Very intense exercise temporarily impairs kidney function (a natural, safe, and regular process). However, the research wanted to see if a high protein diet would produce a detrimental impact on this physiological aspect. So analyses were performed before and directly after a bout of very intense (cycling) exercise.
Some of the athlete's in the study were documented to have protein intakes as high as 2.8 grams per kilogram of body weight per day. However, when the results came in, the high protein athletes showed no fundamental differences that could be associated with damage or impaired kidney function in any way.
These athletes did show higher values for creatinine and uric acid clearance, However, all readings fell within the upper limit of normal levels. Despite the high protein intake there was no accumulation of urea, demonstrating no toxicity. Glomerular filtration rates were normal and there were no signs of even moderate hyperfiltration. This aspect is important.
Hyperfiltration seems to precede the excess excretion of protein plasma into the urine. It is an indicator of the amount of "stress" on the kidneys. The albumin clearance rates also supported the observation that a high protein diet does not stress healthy kidneys. In fact, all readings taken from these athletes proved absolutely normal. Their kidney function was in no way effected by a high protein diet.
The combination of high protein intake and intense exercise didn't appear to impair any aspect of kidney function either. The reduction of several clearance rates as a result of the intense exercise were in line with other reported observations in exercising humans.
Nutritionists often site high protein diets to cause of excessive calcium loss. However, all calcium excretion rates fell within normal ranges. This was despite the bodybuilders taking in higher amounts of calcium in their diets! The bodybuilders absorbed more calcium from their diets! The researchers suggested one reason for this may be that bodybuilding places a higher load on the musculoskeletal system and therefore bodybuilders require more calcium.
There was no difference between the bodybuilder's and the other athlete's calcium excretion levels.
The medical community uses protein ingestion as a key determinant of kidney function and a marker of kidney "health". High protein diets do produce high amounts of urea, an end product of protein metabolism that is excreted in urine. Because of their physical activity, athletes are at risk of dehydration. Severe dehydration limits urea excretion, so theoretically, high protein diets may place stress on the liver (to oxidize excessive protein) and on the kidneys (causing glomerulonephritis-a mechanism of hypertension).
Research has shown that low protein diets reduce the progression of renal failure in patients with kidney disease. For these two aspects, (but no scientific evidence) high protein diets have earned an undeservedly bad reputation within the medical community.
The scientists responsible for this research concluded that high protein intakes of 170 to 243% of the RDA show no toxicity, dehydration, calcium loss or impairment of kidney function. Also, the researchers cautioned that some of the upper-end clearance ranges of some clinical markers witnessed in this study are not solely related to a high protein diet as many other individual differences play a big part in this regard.
The researchers concluded and recommended that high protein diets should not be used as an "escape goat" to explain these variations.
But one thing I wholeheartdly agree on.....the vast majority of bodybuilders eat FAR more protein than they need. And as I said before, no one knows the consequences of eating higher protein over a long period (decades or lifetimes) in humans. To reiterate what has been covered before, 1.2-1.8 grams protein per kg bodyweight is plenty. Also, some proteins (such as soy) can improve kidney function.
To date there is no published evidence that a high protein diet produces any negative effect on metabolism in bodybuilders or any other type of athletes.
Recently, a comprehensive study completed by Jacques Poortmans and Oliver Dellalieux (published in Int. J. Sport Nutr. & Exerc. Metab. 11;28-35:2001) at the University of Brussels in Belgium investigated this aspect directly.
These scientists assessed whether high protein diets affect the health and kidney function of bodybuilders and other athletes. Their study involved 20 bodybuilders and 18 other highly trained athletes that consumed a high protein diet. (Approximately 2 grams of protein per kilogram of body weight per day. More than double the recommended daily allowance.)
Their diets were analyzed to provide total calorie, protein, fat, carbohydrate, and calcium intake each day. Blood and urine samples were taken from the athletes and spectrum of analyses were performed looking at glomerular filtration rate (creatinine clearance), potential change in glomerular membrane permeability (albumin excretion rate), urea and uric acid clearance, nitrogen and calcium balances and any modification in kidney free water balance.
In addition to the resting condition, the researchers also wanted to obtain other data that would be important to hard training athletes. Very intense exercise temporarily impairs kidney function (a natural, safe, and regular process). However, the research wanted to see if a high protein diet would produce a detrimental impact on this physiological aspect. So analyses were performed before and directly after a bout of very intense (cycling) exercise.
Some of the athlete's in the study were documented to have protein intakes as high as 2.8 grams per kilogram of body weight per day. However, when the results came in, the high protein athletes showed no fundamental differences that could be associated with damage or impaired kidney function in any way.
These athletes did show higher values for creatinine and uric acid clearance, However, all readings fell within the upper limit of normal levels. Despite the high protein intake there was no accumulation of urea, demonstrating no toxicity. Glomerular filtration rates were normal and there were no signs of even moderate hyperfiltration. This aspect is important.
Hyperfiltration seems to precede the excess excretion of protein plasma into the urine. It is an indicator of the amount of "stress" on the kidneys. The albumin clearance rates also supported the observation that a high protein diet does not stress healthy kidneys. In fact, all readings taken from these athletes proved absolutely normal. Their kidney function was in no way effected by a high protein diet.
The combination of high protein intake and intense exercise didn't appear to impair any aspect of kidney function either. The reduction of several clearance rates as a result of the intense exercise were in line with other reported observations in exercising humans.
Nutritionists often site high protein diets to cause of excessive calcium loss. However, all calcium excretion rates fell within normal ranges. This was despite the bodybuilders taking in higher amounts of calcium in their diets! The bodybuilders absorbed more calcium from their diets! The researchers suggested one reason for this may be that bodybuilding places a higher load on the musculoskeletal system and therefore bodybuilders require more calcium.
There was no difference between the bodybuilder's and the other athlete's calcium excretion levels.
The medical community uses protein ingestion as a key determinant of kidney function and a marker of kidney "health". High protein diets do produce high amounts of urea, an end product of protein metabolism that is excreted in urine. Because of their physical activity, athletes are at risk of dehydration. Severe dehydration limits urea excretion, so theoretically, high protein diets may place stress on the liver (to oxidize excessive protein) and on the kidneys (causing glomerulonephritis-a mechanism of hypertension).
Research has shown that low protein diets reduce the progression of renal failure in patients with kidney disease. For these two aspects, (but no scientific evidence) high protein diets have earned an undeservedly bad reputation within the medical community.
The scientists responsible for this research concluded that high protein intakes of 170 to 243% of the RDA show no toxicity, dehydration, calcium loss or impairment of kidney function. Also, the researchers cautioned that some of the upper-end clearance ranges of some clinical markers witnessed in this study are not solely related to a high protein diet as many other individual differences play a big part in this regard.
The researchers concluded and recommended that high protein diets should not be used as an "escape goat" to explain these variations.
But one thing I wholeheartdly agree on.....the vast majority of bodybuilders eat FAR more protein than they need. And as I said before, no one knows the consequences of eating higher protein over a long period (decades or lifetimes) in humans. To reiterate what has been covered before, 1.2-1.8 grams protein per kg bodyweight is plenty. Also, some proteins (such as soy) can improve kidney function.
MS, I did read the info in those URLs, and I didn't post them to provide information contrary to the belief that high protein diets do/don't cause renal damage, but merely posted them to provide information regarding what diagnostic features creatinine tests are useful for.
I am also fully aware of the study you have posted. However, the key issue among the vast majority of the studies involving "high" or "excessive" protein intake is that they define "high" and "excessive" as roughly 2g/kg of body mass (and even 2.8g/kg of body mass only equates to 1.27g/lb of body mass). These "extremes" are still far below what the vast majority of bodybuilders on this site insist on consuming.
I am also well aware of the compensatory mechanism whereby glomerular filtration rate and renal reserve will increase in response to increased protein intake. In addition I am well aware of the ability of many organs, including the liver, to increase in mass (size) in response to high protein diets. However, the issue of "high" or "extreme" in these studies lacks any transference to real life becuase the values are still considerably lower than what is commonly consumed. I do, however, recognize that there are several studies conducted on dogs that are fed diets equating to 75% protein, but those studies are performed on nephrectomized subjects.
I've gotta get ready for an exam. I'll be back in a few hours and the I can elaborate on the topic a little more.
I am also fully aware of the study you have posted. However, the key issue among the vast majority of the studies involving "high" or "excessive" protein intake is that they define "high" and "excessive" as roughly 2g/kg of body mass (and even 2.8g/kg of body mass only equates to 1.27g/lb of body mass). These "extremes" are still far below what the vast majority of bodybuilders on this site insist on consuming.
I am also well aware of the compensatory mechanism whereby glomerular filtration rate and renal reserve will increase in response to increased protein intake. In addition I am well aware of the ability of many organs, including the liver, to increase in mass (size) in response to high protein diets. However, the issue of "high" or "extreme" in these studies lacks any transference to real life becuase the values are still considerably lower than what is commonly consumed. I do, however, recognize that there are several studies conducted on dogs that are fed diets equating to 75% protein, but those studies are performed on nephrectomized subjects.
I've gotta get ready for an exam. I'll be back in a few hours and the I can elaborate on the topic a little more.
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I am glad to hear that your are so well informed NJ. Perhaps the other readers on this board are not, so it's good to be clear about what's known versus what is speculation. You gave the impression that your kidneys were damaged by a high protein diet because your creatinine levels were elevated. All I'm pointing out is that creatinine levels can be raised my many things, including creatine supplementation, muscle catabolism, diets high in red meat, dehydration and general high protein intake. High creatinine by itself does not mean you had kidney damage.
We seem to agree that many bodybuilders eat more protein than they need. There is no evidence that this causes damage in the short to medium term. I worry more about the long term consequences of high protein diets, as well as the pure wastefulness (and expense) of eating so much protein. Having coached/dieted a woman with kidney disease (not kidney failure) to the Nationals (she got third in her class), I can assure you that very high protein diets are not necessarily harmful to the kidneys. She cycled almost exclusively soy protein, from 1g per kg up to 4g per kg, and her kidneys are as good as they've ever been. But when she was bulking, her protein intake was below 1g/kg. Carbs are the best calories for building muscle mass, plain and simple. But it's pretty hard to diet down to ultralow bodyfat while retaining muscle WITHOUT a high protein diet.
We seem to agree that many bodybuilders eat more protein than they need. There is no evidence that this causes damage in the short to medium term. I worry more about the long term consequences of high protein diets, as well as the pure wastefulness (and expense) of eating so much protein. Having coached/dieted a woman with kidney disease (not kidney failure) to the Nationals (she got third in her class), I can assure you that very high protein diets are not necessarily harmful to the kidneys. She cycled almost exclusively soy protein, from 1g per kg up to 4g per kg, and her kidneys are as good as they've ever been. But when she was bulking, her protein intake was below 1g/kg. Carbs are the best calories for building muscle mass, plain and simple. But it's pretty hard to diet down to ultralow bodyfat while retaining muscle WITHOUT a high protein diet.
This has been a pleasant discussion and I'm impressed that it hasn't degraded to a flame war (not that I would expect that from you; in the time that I've been on this board, I've noticed that you are well informed, articulate, and tactful.).
I'll be the first to admit that I don't know a great deal about nutrition, but I do understand more than the vast majority of the members of this board--I'm a kinesiologist, not a renal dietician. But I do have experience with consuming large quantities of protein while having normal kidney function as well as compromised kidney function due to the fact that I lacerated one of my kidneys a couple of years ago during a baseball training camp and consequently had it removed. So I've tested the waters on both sides.
I also agree with your assertion that bodybuilders essentially waste a lot of protein. The quantities that I see recommended on this, and the majority of other boards, basically equates to an expensive source of additional calories. But I strongly believe that most of the studies concluding that there are few, if any, short-medium term side effects of high protein intake are not reflective of real world "high" protein consumption that typically exceeds the studies standards of "high" by magnitudes of 2-3 times.
One of my main concerns, however, is that bodybuilders don't just consume large amounts of protein. A lot of them take huge amounts of diuretics like ECA stacks in conjunction with their 2-3g of protein per lb of body mass. I have yet to find any studies conducted specifically on the effects of high protein and diuretic intake and their effects on renal health. I would theorize though, that the combined effect likely causes varying degrees of kidney damage depending on the supplement quantities and duration of supplementation.
Perhaps, people who are reading this thread, if they feel so inclined, could have the blood work done that I suggested, and we could effectively conduct a pseudo-epidemiological study based on real-world bodybuilding protein consumption. They could post the results of their blood work, their daily protein consumption, and their consumption of ECA stacks (or other "fat burning" diuretics).
I'll be the first to admit that I don't know a great deal about nutrition, but I do understand more than the vast majority of the members of this board--I'm a kinesiologist, not a renal dietician. But I do have experience with consuming large quantities of protein while having normal kidney function as well as compromised kidney function due to the fact that I lacerated one of my kidneys a couple of years ago during a baseball training camp and consequently had it removed. So I've tested the waters on both sides.
I also agree with your assertion that bodybuilders essentially waste a lot of protein. The quantities that I see recommended on this, and the majority of other boards, basically equates to an expensive source of additional calories. But I strongly believe that most of the studies concluding that there are few, if any, short-medium term side effects of high protein intake are not reflective of real world "high" protein consumption that typically exceeds the studies standards of "high" by magnitudes of 2-3 times.
One of my main concerns, however, is that bodybuilders don't just consume large amounts of protein. A lot of them take huge amounts of diuretics like ECA stacks in conjunction with their 2-3g of protein per lb of body mass. I have yet to find any studies conducted specifically on the effects of high protein and diuretic intake and their effects on renal health. I would theorize though, that the combined effect likely causes varying degrees of kidney damage depending on the supplement quantities and duration of supplementation.
Perhaps, people who are reading this thread, if they feel so inclined, could have the blood work done that I suggested, and we could effectively conduct a pseudo-epidemiological study based on real-world bodybuilding protein consumption. They could post the results of their blood work, their daily protein consumption, and their consumption of ECA stacks (or other "fat burning" diuretics).
Blood&Iron
New member
I, for one, would be willing to have some blood tests done. But I first have to check what it'd cost me. Don't have a ton of spare cash. Plus I'm using creatine which will invalidate at least the creatinine test. Suppose I could stop using 2-3 weeks prior to let it clear out of my systems, but I'm not sure I want to do that. Beside I'm only getting about 250g of protein at a weight of 210 lbs. so I'm not consuming "vast" amounts of protein anyway--at least in my opinion. If I have any tests done, I'll post the results.
Seems to me that the real world tests and the, more or less, proof that high protein diets aren't that bad for you can be seen in 60 years of bodybuilders consuming high protein. Not that I'm a bodybuilding historian or anything, but I don't recall a single one dying from kidney failure. Some definitely have probelms with their kidneys(that Long fellow and, I think, Flex) but I would bet that has just a little bit more to do with huge amounts of drug use than it does with their protein intake.
Maybe NJ-10 is reading my mind! I also worry about the combo of not just high protein and ECA, but ECA by itself. This combo of drugs (ephedrine/caffeine and aspirin) is directly toxic to kidney cells. I can imagine some bodybuilder eating 3+grams of protein per kg each day while taking an ECA stack 3 times per day, then she gets an ear infection and goes to the doc (and doesn't tell doc about her high protein/ECA intake) and doc gives her a course of aminoglycoside antibiotics. Even without dehydration/diuresis, the above combo could be pretty devastating to a perfectly healthy kidney!
It's sad but true that the highest profile bodybuilders also take huge amounts of potentially nephrotoxic drugs. It makes it pretty hard to draw any conclusions based purely on the presence or absence of kidney failure in this population.
Until we have long term studies following people that eat chronically high protein diets (in the absence of toxic drug abuse) we may never know for sure. It seems prudent to me to only eat as much protein as you actually need, plus perhaps a tad extra for insurance. The 1.2g to 1.8g/kg guideline meets this criteria nicely for the majority of bodybuilders. I think most bodybuilders would also benefit from cycling their protein intake. It gives the liver/kidneys a break, and also makes the body more efficient at assimilating and using the protein you eat. Not to mention those extra carbs give ya a real metabolic/anabolic boost.
It's sad but true that the highest profile bodybuilders also take huge amounts of potentially nephrotoxic drugs. It makes it pretty hard to draw any conclusions based purely on the presence or absence of kidney failure in this population.
Until we have long term studies following people that eat chronically high protein diets (in the absence of toxic drug abuse) we may never know for sure. It seems prudent to me to only eat as much protein as you actually need, plus perhaps a tad extra for insurance. The 1.2g to 1.8g/kg guideline meets this criteria nicely for the majority of bodybuilders. I think most bodybuilders would also benefit from cycling their protein intake. It gives the liver/kidneys a break, and also makes the body more efficient at assimilating and using the protein you eat. Not to mention those extra carbs give ya a real metabolic/anabolic boost.
Blood&Iron
New member
MS-
I was not aware of ECA having any sort of effect on kidney functioning. I'm certainly no pharmacologist but as I recall adrenoreceptor agonists have adverse effects only on the cardiovascular and central nervous systems. Can you explain how ECA, besides having a diuretic effect, would affect kidney functioning?
I was not aware of ECA having any sort of effect on kidney functioning. I'm certainly no pharmacologist but as I recall adrenoreceptor agonists have adverse effects only on the cardiovascular and central nervous systems. Can you explain how ECA, besides having a diuretic effect, would affect kidney functioning?
Ephedrine (by itself) is implicated in the formation of kidney stones. Ephedrine also reduces blood flow through the kidneys. Chronic caffeine+analgesic use, both through diuresis and direct toxicity to kidney cells, can lead to kidney failure (note this seems to be a synergistic effect that is not seen with caffeine or aspirin taken by themselves). Caffeine/aspirin, in the presence of reduced blood flow and dehydration (due to diuresis) is about the worst mix I can dream up for kidney health! Because many bodybuilders/dieters use ECA combos chronically, they are putting themselves at greater risk for kidney problems. No one knows what adding a long term, very high protein diet on top of this stack will do to kidneys. It seems like a bad idea to me.
