How much protein can the body absorb in one sitting?

[343paul]

I guess it depends on the quality of protein.

[Rippinit]

i have been read in several places that the body can handle 30 grams in one sitting, however this is subjective to time between sittings, bodyweight, and, with regards to muscle building, how much carbohydrate one consumes- although im not sure if it has been proven. This is due to the fact that carbohydrate has a protein sparing effect. Quality-wise i dont know, although i dont believe it would make a difference as to how much the body can assimilate.

[RB12]

Originally Posted by thegame99

Your body can absorb 30-40 grams. After that you're just drinking the protein for fun.

The protein powder can hurt your kidneys.

strong 3-year old bump

care to post some support for this or do you just want to bump old threads with irresponsible banter?

[WillBrink]

Originally Posted by extreme4377

My question is just that. How much protein can you body absorb in one sitting?

From the QnA section on my site:

It has been a long debated topic how much protein a person can digest at any one time. Nutritionists and doctors have maintained for decades that "people can only digest 30 grams at a time of protein and any additional protein is wasted or converted to fat." So say the powers that be.

Now, I wish I could examine the study or research they are basing this advice on so I could dispute it but I can't. Why you ask? Because in all my years of searching the medical data banks, talking to researchers, and falling asleep in the medical library after hours of reading, I have been unable to find exactly where this advice comes from or what it's based on.

At one time, I went so far as to offer a reward to anyone who could show me a recent study that showed that 30 grams of protein was the upper limit anyone could digest, regardless of age, weight, and activity levels.

Why is it 30 grams? Why not 28 or 35? Are we saying that the digestive and absorptive abilities of a 285 pound 23 year old football player is the same as a 50 year old 115 pound women?

Now digestion is a very complex topic. Many people think you eat some protein, it mixes with some acid or something, gets broken down into amino acids, gets taken up into the body, and everyone is happy.

I wish it were that simple. As with all foods, the breakdown of protein starts in the mouth with the simple chewing of food and the exposer to certain enzymes. In the stomach, food mixes with enzymes and other factors such as lipase, pepsin, intrinsic factor, and of course HCL (stomach acid).

It moves onto the small intestine and then the large intestine.The small intestine is considered the major anatomical site of food digestion and nutrient absorption and is made up of section such as the duodenum, jejunum, and the ileum. Pancreatic enzymes (chymotrypsin, trypsin, etc.), bile salts, gastrin, cholecystokinin, pepidases, as well as many others factors are released here.

The large intestine is composed of the ascending colon, transverse colon, descending colon, and the sigmoid colon, which all play a part in absorbing the nutrients we eat. Sound complicated? It is. Believe me, I am leaving out a great deal of information so you wont fall asleep reading my little column! Suffice it to say, digestion is a very complicated thing and there are many places along the chain of digestion that can both enhance and degrade a persons ability to absorb the foods we eat.

There is no reason to think that among this complicated process that there are not wide individual differences in a persons ability to digest and absorb protein. For some person who is inactive, elderly, and for what ever reason lives with compromised digestion, 30 grams of protein at one sitting might very well be too much for them to handle.

By the same token, assuming a 220lbs healthy athlete is unable to exceed 30 grams of protein in one sitting is neither proven by medial science or even logical in my view. So what if the 30 gram rule turns out to be true? If we examine some of the more recent studies on the protein requirements of athletes done by researchers from both the United Sates and Canada , we come to some recommended protein intakes that far exceed the RDAs, some times by as mush as 225%!

These researchers came to the conclusion that protein intakes for athletes should range from approximately 1.2 grams of protein per kilogram of bodyweight for endurance athletes and up to 1.8g of protein per kg for strength training athletes. For a 200 pound bodybuilder-a strength training athlete-that would be approximately 164 grams of protein per day (most bodybuilders I know eat considerably more protein per day, but that's for another fight and another article...). Assuming that 30 grams of protein is the most anyone can digest, absorb, and utilize, this person would have to split his intake into about five meals (164 divided by 30 = 5.47). So, given the advice by many people that 30 grams is all anyone can digest at a single sitting, it appears a person can achieve the goal of 30 grams of protein per meal even with the higher intakes recommended in the modern research (assuming they are willing or able to eat five meals per day).

However, if you happen to eat more than that per meal as a healthy athlete I don't think you have anything to worry about. I wont tell anyone. Me, I would suggest you stick to the one gram per pound of bodyweight rule, which often exceeds the research mentioned above. Also, read the "Protein Myth" article at the BrinkZone site for more info on this topic.

http://www.brinkzone.com/articledeta...catid=6&aid=62

[NO HYPE]

Originally Posted by extreme4377

My question is just that. How much protein can you body absorb in one sitting? And how often can you intake more protein?

There is no reason to rapidly consume dietary protein.

I will return later with references however, I believe the maximum absorption rate of whey protein has been observed at around 10 grams per-hour (and less for casein), so the slower you consume your protein.... the more efficiently it is utilized for protein synthesis.

[GeneGnomeX]

I don't think most people understand that when you eat whole foods it takes hours to digest. You don't have to eat small meals every hour to keep the protein coming, it doesn't all dump into circulation right away.

[labradarep]

Originally Posted by PittsburghKid

How can Proteins turn into fat? I've never heard that before.

Protein does not directly turn into fat. It first must go through a process called Gluconeogenesis( Gluconeogenesis is the generation of glucose from non-sugar carbon substrates like pyruvate, lactate, glycerol, and glucogenic amino acids.)

The vast majority of gluconeogenesis takes place in the liver and, to a smaller extent, in the cortex of kidneys. This process occurs during periods of fasting, starvation, or intense exercise and is highly endergonic. Gluconeogenesis is often associated with ketosis.(ie: Amino Acids , which are the building blocks of protein, are converted to glucose). These new glucose molecules then get stored as fat if they are not utilized for exercise, metabolism, etc.. That is how Protein gets stored as fat in a round about way.

Hope this helps?

[Elliptical Envy]

Originally Posted by labradarep

Protein does not directly turn into fat. It first must go through a process called Gluconeogenesis( Gluconeogenesis is the generation of glucose from non-sugar carbon substrates like pyruvate, lactate, glycerol, and glucogenic amino acids.)

The vast majority of gluconeogenesis takes place in the liver and, to a smaller extent, in the cortex of kidneys. This process occurs during periods of fasting, starvation, or intense exercise and is highly endergonic. Gluconeogenesis is often associated with ketosis.(ie: Amino Acids , which are the building blocks of protein, are converted to glucose). These new glucose molecules then get stored as fat if they are not utilized for exercise, metabolism, etc.. That is how Protein gets stored as fat in a round about way.

Hope this helps?

I really like how you explained that. Kudos to you.

BTW, Fitnecise I agree with your statement as well.

[Quelly]

omfg there is so much crap info in this thread...thank god for the last couple of posters

take home messages

overeat any macronutrient, you will be in a caloric surplus and gain bodyfat

no reason to eat over 1-1.5g/lb of bodyweight in protein, and even that is probably more than needed anyway

we have no studies showing how much protein can be utilized in one sitting or time period to this date

[NO HYPE]

Originally Posted by NO HYPE

There is no reason to rapidly consume dietary protein.

I will return later with references however, I believe the maximum absorption rate of whey protein has been observed at around 10 grams per-hour (and less for casein), so the slower you consume your protein.... the more efficiently it is utilized for protein synthesis.

A few highlights....


A Review of Issues of Dietary Protein Intake in Humans

Considerable debate has taken place over the safety and validity of increased protein intakes for both weight control and muscle synthesis. The advice to consume diets high in protein by some health professionals, media and popular diet books is given despite a lack of scientific data on the safety of increasing protein consumption. The key issues are the rate at which the gastrointestinal tract can absorb amino acids from dietary proteins (1.3 to 10 g/h) and the liver's capacity to deaminate proteins and produce urea for excretion of excess nitrogen. The accepted level of protein requirement of 0.8g ∙ kg-1 ∙ d-1 is based on structural requirements and ignores the use of protein for energy metabolism. High protein diets on the other hand advocate excessive levels of protein intake on the order of 200 to 400 g/d, which can equate to levels of approximately 5 g ∙ kg-1 ∙ d-1, which may exceed the liver?s capacity to convert excess nitrogen to urea. Dangers of excessive protein, defined as when protein constitutes > 35% of total energy intake, include hyperaminoacidemia, hyperammonemia, hyperinsulinemia nausea, diarrhea, and even death (the ?rabbit starvation syndrome?). The three different measures of defining protein intake, which should be viewed together are: absolute intake (g/d), intake related to body weight (g ∙ kg-1 ∙ d-1) and intake as a fraction of total energy (percent energy). A suggested maximum protein intake based on bodily needs, weight control evidence, and avoiding protein toxicity would be approximately of 25% of energy requirements at approximately 2 to 2.5 g ∙ kg-1 ∙ d-1, corresponding to 176 g protein per day for an 80 kg individual on a 12,000kJ/d diet. This is well below the theoretical maximum safe intake range for an 80 kg person (285 to 365 g/d).

Amino acid catabolism must occur in a way that does not elevate blood ammonia (26). Catabolism of amino acids occurs in the liver, which contains the urea cycle (26), however the rate of conversion of amino acid derived ammonia to urea is limited. Rudman et al. (27)

Early findings suggest that rapidly absorbed proteins such as free amino acids and WP, transiently and moderately inhibit protein breakdown (39, 53), yet stimulate protein synthesis by 68% [using nonoxidative leucine disposal (NOLD) as an index of protein synthesis] (54). Casein protein has been shown to inhibit protein breakdown by 30% for a 7-h postprandial period, and only slightly increase protein synthesis (38, 54). Rapidly absorbed amino acids despite stimulating greater protein synthesis, also stimulate greater amino acid oxidation, and hence results in a lower net protein gain, than slowly absorbed protein (54). Leucine balance, a measurable endpoint for protein balance, is indicated in Figure 1, which shows slowly absorbed amino acids (~ 6 to 7 g/h), such as CAS and 2.3 g of WP repeatedly taken orally every 20 min (RPT-WP), provide significantly better protein balance than rapidly absorbed amino acids (39, 54).

The misconception in the fitness and sports industries is that rapidly absorbed protein, such as WP and AA promote better protein anabolism. As the graph shows, slowly absorbed protein such as CAS and small amounts of WP (RPT-WP) provide four and nine times more protein synthesis than WP.

This ?slow? and ?fast? protein concept provides some clearer evidence that although human physiology may allow for rapid and increased absorption rate of amino acids, as in the case of WP (8 to 10 g/h), this fast absorption is not strongly correlated with a ?maximal protein balance,? as incorrectly interpreted by fitness enthusiasts, athletes, and bodybuilders.

Using the findings of amino acid absorption rates shown in Table 2 (using leucine balance as a measurable endpoint for protein balance), a maximal amino acid intake measured by the inhibition of proteolysis and increase in postprandial protein gain, may only be ~ 6 to 7 g/h (as described by RPT-WP, and casein) (38), which corresponds to a maximal protein intake of 144 to 168 g/d.

The rate of amino acid absorption from protein is quite slow (~ 5 to 8 g/h, from Table 2) when compared to that of other macronutrients, with fatty acids at ~ 0.175 g ? kg-1 ? h-1 (~ 14 g/h) (55) and glucose 60 to 100 g/h (0.8 to 1.2 g carbohydrate ? kg-1 ? h-1) for an 80 kg individual (56). From our earlier calculations elucidating the maximal amounts of protein intake from MRUS, an 80 kg subject could theoretically tolerate up to 301 to 365 g of protein per day, but this would require an absorption rate of 12.5 to 15 g/h, an unlikely level given the results of the studies reported above.

The consumption of large amounts of protein by athletes and bodybuilders is not a new practice (13). Recent evidence suggests that increased protein intakes for endurance and strength-trained athletes can increase strength and recovery from exercise (14, 80, 81). In healthy adult men consuming small frequent meals providing protein at 2.5 g ? kg-1 ? d-1, there was a decreased protein breakdown, and increased protein synthesis of up to 63%, compared with intakes of 1g ? kg-1 ? d-1 (16). Subjects receiving 1g ? kg-1 ? d-1 underwent muscle protein breakdown with less evident changes in muscle protein synthesis. Some evidence suggests, however, that a high protein diet increases leucine oxidation (82, 83), while other data demonstrate that the slower digestion rate of protein (38, 54), and the timing of protein ingestion (with resistance training) (84) promote muscle protein synthesis.

Absorption rates of amino acids from the gut can vary from 1.4 g/h for raw egg white to 8 to 10 g/h for whey protein isolate. Slowly absorbed amino acids such as casein (~ 6 g/h) and repeated small doses of whey protein (2.9 g per 20 min, totaling ~ 7 g/h) promote leucine balance, a marker of protein balance, superior to that of a single dose of 30 g of whey protein or free amino acids which are both rapidly absorbed (8 to 10 g/h), and enhance amino acid oxidation. This gives us an initial understanding that although higher protein intakes are physiologically possible, and tolerable by the human body, they may not be functionally optimal in terms of building and preserving body protein. The general, although incorrect consensus among athletes and bodybuilders, is that rapid protein absorption corresponds to greater muscle building.

From the limited data available on amino acid absorption rates, and the physiological parameters of urea synthesis, the maximal safe protein intakes for humans have been estimated at ~ 285 g/d for an 80 kg male. It is not the intention of this article, however, to promote the consumption of large amounts of protein, but rather to prompt an investigation into what are the parameters of human amino acid kinetics. In the face of the rising tide of obesity in the Western world where energy consumption overrides energy expenditure, a more prudent and practical approach, which may still provide favorable outcomes, is a 25% protein energy diet, which would provide 118 g protein on an 8000 kJ/d diet at 1.5 g ? kg-1 ? d-1 for an 80 kg individual (Table 2).

Little data exists on the comprehensive metabolic effects of large amounts of dietary protein in the order of 300 to 400 g/d. Intakes of this magnitude would result in some degree of prolonged hyperaminoacidemia, hyperammonemia, hyperinsulinemia, and hyperglucagonemia, and some conversion to fat, but the metabolic and physiological consequences of such states are currently unknown. The upper limit of protein intake is widely debated, with many experts advocating levels up to 2.0 g ? kg-1 ? d-1 being quite safe (102, 117, 118) and that renal considerations are not an issue at this level in individuals with normal renal function. http://www.humankinetics.com/eJourna.../pdfs/5642.pdf

[NO HYPE]

Originally Posted by Quelly

omfg there is so much crap info in this thread...thank god for the last couple of posters

Why thank you.... JK

Originally Posted by Quelly

we have no studies showing how much protein can be utilized in one sitting or time period to this date

Slow and fast dietary proteins differently modulate postprandial accretion. Boirie, Y., M. Dangin, P. Gachon, M.P. Vasson, J.L. Maubois, and B. Beaufrere. Proc. Natl. Acad. Sci. 94: 14930-14935, 1997.

[Belloc]

I red a study were they looked into different feeding methods, one of them was the 'warrior diet' were you only eat one meal a day

anyway something about nitrogen in urine showed that eating all your protein in one sitting caused no protein loss

[Quelly]

Originally Posted by NO HYPE

Why thank you.... JK





Slow and fast dietary proteins differently modulate postprandial accretion. Boirie, Y., M. Dangin, P. Gachon, M.P. Vasson, J.L. Maubois, and B. Beaufrere. Proc. Natl. Acad. Sci. 94: 14930-14935, 1997.

New info, good stuff...I guess a better way to put it, is that there is no magic number for how much protein you can take in during one sitting, one has to account for bodyweight, type of protein, and probably other factors....arbitrarily saying "30g is the most you can absorb" is wrong.

[NO HYPE]

Originally Posted by Quelly

New info, good stuff...I guess a better way to put it, is that there is no magic number for how much protein you can take in during one sitting, one has to account for bodyweight, type of protein, and probably other factors....arbitrarily saying "30g is the most you can absorb" is wrong.

Agreed.

[tomdatrain]

it makes more sense to get your protein from whole foods spread out over 6-8 meals during the day along with a pre-worout and post-workout shake to give the muscle a little extra boost in growth

[AphtaLyfe]

Originally Posted by NO HYPE

A few highlights....


A Review of Issues of Dietary Protein Intake in Humans

Considerable debate has taken place over the safety and validity of increased protein intakes for both weight control and muscle synthesis. The advice to consume diets high in protein by some health professionals, media and popular diet books is given despite a lack of scientific data on the safety of increasing protein consumption. The key issues are the rate at which the gastrointestinal tract can absorb amino acids from dietary proteins (1.3 to 10 g/h) and the liver's capacity to deaminate proteins and produce urea for excretion of excess nitrogen. The accepted level of protein requirement of 0.8g ∙ kg-1 ∙ d-1 is based on structural requirements and ignores the use of protein for energy metabolism. High protein diets on the other hand advocate excessive levels of protein intake on the order of 200 to 400 g/d, which can equate to levels of approximately 5 g ∙ kg-1 ∙ d-1, which may exceed the liver?s capacity to convert excess nitrogen to urea. Dangers of excessive protein, defined as when protein constitutes > 35% of total energy intake, include hyperaminoacidemia, hyperammonemia, hyperinsulinemia nausea, diarrhea, and even death (the ?rabbit starvation syndrome?). The three different measures of defining protein intake, which should be viewed together are: absolute intake (g/d), intake related to body weight (g ∙ kg-1 ∙ d-1) and intake as a fraction of total energy (percent energy). A suggested maximum protein intake based on bodily needs, weight control evidence, and avoiding protein toxicity would be approximately of 25% of energy requirements at approximately 2 to 2.5 g ∙ kg-1 ∙ d-1, corresponding to 176 g protein per day for an 80 kg individual on a 12,000kJ/d diet. This is well below the theoretical maximum safe intake range for an 80 kg person (285 to 365 g/d).

Amino acid catabolism must occur in a way that does not elevate blood ammonia (26). Catabolism of amino acids occurs in the liver, which contains the urea cycle (26), however the rate of conversion of amino acid derived ammonia to urea is limited. Rudman et al. (27)

Early findings suggest that rapidly absorbed proteins such as free amino acids and WP, transiently and moderately inhibit protein breakdown (39, 53), yet stimulate protein synthesis by 68% [using nonoxidative leucine disposal (NOLD) as an index of protein synthesis] (54). Casein protein has been shown to inhibit protein breakdown by 30% for a 7-h postprandial period, and only slightly increase protein synthesis (38, 54). Rapidly absorbed amino acids despite stimulating greater protein synthesis, also stimulate greater amino acid oxidation, and hence results in a lower net protein gain, than slowly absorbed protein (54). Leucine balance, a measurable endpoint for protein balance, is indicated in Figure 1, which shows slowly absorbed amino acids (~ 6 to 7 g/h), such as CAS and 2.3 g of WP repeatedly taken orally every 20 min (RPT-WP), provide significantly better protein balance than rapidly absorbed amino acids (39, 54).

The misconception in the fitness and sports industries is that rapidly absorbed protein, such as WP and AA promote better protein anabolism. As the graph shows, slowly absorbed protein such as CAS and small amounts of WP (RPT-WP) provide four and nine times more protein synthesis than WP.

This ?slow? and ?fast? protein concept provides some clearer evidence that although human physiology may allow for rapid and increased absorption rate of amino acids, as in the case of WP (8 to 10 g/h), this fast absorption is not strongly correlated with a ?maximal protein balance,? as incorrectly interpreted by fitness enthusiasts, athletes, and bodybuilders.

Using the findings of amino acid absorption rates shown in Table 2 (using leucine balance as a measurable endpoint for protein balance), a maximal amino acid intake measured by the inhibition of proteolysis and increase in postprandial protein gain, may only be ~ 6 to 7 g/h (as described by RPT-WP, and casein) (38), which corresponds to a maximal protein intake of 144 to 168 g/d.

The rate of amino acid absorption from protein is quite slow (~ 5 to 8 g/h, from Table 2) when compared to that of other macronutrients, with fatty acids at ~ 0.175 g ? kg-1 ? h-1 (~ 14 g/h) (55) and glucose 60 to 100 g/h (0.8 to 1.2 g carbohydrate ? kg-1 ? h-1) for an 80 kg individual (56). From our earlier calculations elucidating the maximal amounts of protein intake from MRUS, an 80 kg subject could theoretically tolerate up to 301 to 365 g of protein per day, but this would require an absorption rate of 12.5 to 15 g/h, an unlikely level given the results of the studies reported above.

The consumption of large amounts of protein by athletes and bodybuilders is not a new practice (13). Recent evidence suggests that increased protein intakes for endurance and strength-trained athletes can increase strength and recovery from exercise (14, 80, 81). In healthy adult men consuming small frequent meals providing protein at 2.5 g ? kg-1 ? d-1, there was a decreased protein breakdown, and increased protein synthesis of up to 63%, compared with intakes of 1g ? kg-1 ? d-1 (16). Subjects receiving 1g ? kg-1 ? d-1 underwent muscle protein breakdown with less evident changes in muscle protein synthesis. Some evidence suggests, however, that a high protein diet increases leucine oxidation (82, 83), while other data demonstrate that the slower digestion rate of protein (38, 54), and the timing of protein ingestion (with resistance training) (84) promote muscle protein synthesis.

Absorption rates of amino acids from the gut can vary from 1.4 g/h for raw egg white to 8 to 10 g/h for whey protein isolate. Slowly absorbed amino acids such as casein (~ 6 g/h) and repeated small doses of whey protein (2.9 g per 20 min, totaling ~ 7 g/h) promote leucine balance, a marker of protein balance, superior to that of a single dose of 30 g of whey protein or free amino acids which are both rapidly absorbed (8 to 10 g/h), and enhance amino acid oxidation. This gives us an initial understanding that although higher protein intakes are physiologically possible, and tolerable by the human body, they may not be functionally optimal in terms of building and preserving body protein. The general, although incorrect consensus among athletes and bodybuilders, is that rapid protein absorption corresponds to greater muscle building.

From the limited data available on amino acid absorption rates, and the physiological parameters of urea synthesis, the maximal safe protein intakes for humans have been estimated at ~ 285 g/d for an 80 kg male. It is not the intention of this article, however, to promote the consumption of large amounts of protein, but rather to prompt an investigation into what are the parameters of human amino acid kinetics. In the face of the rising tide of obesity in the Western world where energy consumption overrides energy expenditure, a more prudent and practical approach, which may still provide favorable outcomes, is a 25% protein energy diet, which would provide 118 g protein on an 8000 kJ/d diet at 1.5 g ? kg-1 ? d-1 for an 80 kg individual (Table 2).

Little data exists on the comprehensive metabolic effects of large amounts of dietary protein in the order of 300 to 400 g/d. Intakes of this magnitude would result in some degree of prolonged hyperaminoacidemia, hyperammonemia, hyperinsulinemia, and hyperglucagonemia, and some conversion to fat, but the metabolic and physiological consequences of such states are currently unknown. The upper limit of protein intake is widely debated, with many experts advocating levels up to 2.0 g ? kg-1 ? d-1 being quite safe (102, 117, 118) and that renal considerations are not an issue at this level in individuals with normal renal function. http://www.humankinetics.com/eJourna.../pdfs/5642.pdf

Nice find!

Just bought some casein to mix in with my whey...

[CoolAsAFan]

been reading ALOT on this forum, no hype, u seem to be on every thread that I find of particular interest and informative, reps to you man.

I have a question after reading that study posted by no hype, mainly
"A suggested maximum protein intake based on bodily needs, weight control evidence, and avoiding protein toxicity would be approximately of 25% of energy requirements at approximately 2 to 2.5 g ∙ kg-1 ∙ d-1, corresponding to 176 g protein per day for an 80 kg individual on a 12,000kJ/d diet."

I weigh roughly a bit more then 80kg, but I was wondering, the 176g protein intake, is that for the whole day including what i eat, not just shakes? I guess I just got confused cus the study only talks about WP and CAS. And am I understanding this right that I should actually be consuming more CAS than WP in my shakes except for maybe Post W.O?

[mlgray40]

So according to the article a 80kg male will only use 7-8g of whey per hour. So if you ate 7-8g of whey every hour all day the most your body would use is 168-192g? Am I understanding that right?

[JonZ]

Some good info above.

"These researchers came to the conclusion that protein intakes for athletes should range from approximately 1.2 grams of protein per kilogram of bodyweight for endurance athletes and up to 1.8g of protein per kg for strength training athletes. For a 200 pound bodybuilder-a strength training athlete-that would be approximately 164 grams of protein per day (most bodybuilders I know eat considerably more protein per day, but that's for another fight and another article"

Thank you for pasting that.

"up to 1.8g of protein per kg for strength training athletes"

Judging by what Ive read here, other forums,used to read in magazines,heard in teh gym etc,what most weightlifters actually go by pound of lean weight not kilograms of bodyweight which is why you see guys talking about taking up 400g and more per day - which to me is way too much. Divided by 6 meals, that would be 67g a meal.



I get in 20 - 30g per meal. Im about 210 lean bodyweight -at 6 meals a day you have say 180g of protein. Eating more not only makes me feel bloated and over stuffed but Ive also noticeably over time gained bodyfat from eating more than that.

I dont remember where I read it, it was sometime during the 90s about the 30g a meal rule,which Ive pretty much stuck to.

There are guys out there who eat 80g per meal, while others like Mentzer believed all you needed was a healthy diet, plus a bit extra muscle your trying to build.So youll always get a different answer depending on who you ask.

For me it led to only more questions, because as a natural lifter, you couldnt go by what drug users would say or recommend. So Ive always wondered if I was taking in enough protein to grow properly.


BTW, I have gout and can tell you that higher amounts of protein have affected my kidneys. I can feel it and my body will tell me when to tone it down. Food contains not only calories, protein,etc but also purines which can raise uric acid levels and do affect the kidneys. Even in peopel without my condition.

Just last week, someone I know who has kidney stone issues in the past actually ended up going to the doctor from eating a entire bundle of asparagus in one sitting. The next day he almost collapsed and it took a week for him to recover.

[dgj23]

I gained over 30lbs of muscle eating less than 1g of protein per body lb and eating less than 2000 calories a day. I probably ate less than 50g of protein a day. I weigh 185lb. My muscle growth did plateau so I am eating a lot more protein. So is taking protein exactly after a work out necessary because after I go to the gym I drive home and work on my abs. Then I eat a meal with about 40 to 50 grams of protein. I am trying to make my body proportional before I do any major bulking up. I am still learning how to body build.

[Phosphate bond]

Originally Posted by NO HYPE

A few highlights....


A Review of Issues of Dietary Protein Intake in Humans

Considerable debate has taken place over the safety and validity of increased protein intakes for both weight control and muscle synthesis. The advice to consume diets high in protein by some health professionals, media and popular diet books is given despite a lack of scientific data on the safety of increasing protein consumption. The key issues are the rate at which the gastrointestinal tract can absorb amino acids from dietary proteins (1.3 to 10 g/h) and the liver's capacity to deaminate proteins and produce urea for excretion of excess nitrogen. The accepted level of protein requirement of 0.8g ∙ kg-1 ∙ d-1 is based on structural requirements and ignores the use of protein for energy metabolism. High protein diets on the other hand advocate excessive levels of protein intake on the order of 200 to 400 g/d, which can equate to levels of approximately 5 g ∙ kg-1 ∙ d-1, which may exceed the liver?s capacity to convert excess nitrogen to urea. Dangers of excessive protein, defined as when protein constitutes > 35% of total energy intake, include hyperaminoacidemia, hyperammonemia, hyperinsulinemia nausea, diarrhea, and even death (the ?rabbit starvation syndrome?). The three different measures of defining protein intake, which should be viewed together are: absolute intake (g/d), intake related to body weight (g ∙ kg-1 ∙ d-1) and intake as a fraction of total energy (percent energy). A suggested maximum protein intake based on bodily needs, weight control evidence, and avoiding protein toxicity would be approximately of 25% of energy requirements at approximately 2 to 2.5 g ∙ kg-1 ∙ d-1, corresponding to 176 g protein per day for an 80 kg individual on a 12,000kJ/d diet. This is well below the theoretical maximum safe intake range for an 80 kg person (285 to 365 g/d).

Amino acid catabolism must occur in a way that does not elevate blood ammonia (26). Catabolism of amino acids occurs in the liver, which contains the urea cycle (26), however the rate of conversion of amino acid derived ammonia to urea is limited. Rudman et al. (27)

Early findings suggest that rapidly absorbed proteins such as free amino acids and WP, transiently and moderately inhibit protein breakdown (39, 53), yet stimulate protein synthesis by 68% [using nonoxidative leucine disposal (NOLD) as an index of protein synthesis] (54). Casein protein has been shown to inhibit protein breakdown by 30% for a 7-h postprandial period, and only slightly increase protein synthesis (38, 54). Rapidly absorbed amino acids despite stimulating greater protein synthesis, also stimulate greater amino acid oxidation, and hence results in a lower net protein gain, than slowly absorbed protein (54). Leucine balance, a measurable endpoint for protein balance, is indicated in Figure 1, which shows slowly absorbed amino acids (~ 6 to 7 g/h), such as CAS and 2.3 g of WP repeatedly taken orally every 20 min (RPT-WP), provide significantly better protein balance than rapidly absorbed amino acids (39, 54).

The misconception in the fitness and sports industries is that rapidly absorbed protein, such as WP and AA promote better protein anabolism. As the graph shows, slowly absorbed protein such as CAS and small amounts of WP (RPT-WP) provide four and nine times more protein synthesis than WP.

This ?slow? and ?fast? protein concept provides some clearer evidence that although human physiology may allow for rapid and increased absorption rate of amino acids, as in the case of WP (8 to 10 g/h), this fast absorption is not strongly correlated with a ?maximal protein balance,? as incorrectly interpreted by fitness enthusiasts, athletes, and bodybuilders.

Using the findings of amino acid absorption rates shown in Table 2 (using leucine balance as a measurable endpoint for protein balance), a maximal amino acid intake measured by the inhibition of proteolysis and increase in postprandial protein gain, may only be ~ 6 to 7 g/h (as described by RPT-WP, and casein) (38), which corresponds to a maximal protein intake of 144 to 168 g/d.

The rate of amino acid absorption from protein is quite slow (~ 5 to 8 g/h, from Table 2) when compared to that of other macronutrients, with fatty acids at ~ 0.175 g ? kg-1 ? h-1 (~ 14 g/h) (55) and glucose 60 to 100 g/h (0.8 to 1.2 g carbohydrate ? kg-1 ? h-1) for an 80 kg individual (56). From our earlier calculations elucidating the maximal amounts of protein intake from MRUS, an 80 kg subject could theoretically tolerate up to 301 to 365 g of protein per day, but this would require an absorption rate of 12.5 to 15 g/h, an unlikely level given the results of the studies reported above.

The consumption of large amounts of protein by athletes and bodybuilders is not a new practice (13). Recent evidence suggests that increased protein intakes for endurance and strength-trained athletes can increase strength and recovery from exercise (14, 80, 81). In healthy adult men consuming small frequent meals providing protein at 2.5 g ? kg-1 ? d-1, there was a decreased protein breakdown, and increased protein synthesis of up to 63%, compared with intakes of 1g ? kg-1 ? d-1 (16). Subjects receiving 1g ? kg-1 ? d-1 underwent muscle protein breakdown with less evident changes in muscle protein synthesis. Some evidence suggests, however, that a high protein diet increases leucine oxidation (82, 83), while other data demonstrate that the slower digestion rate of protein (38, 54), and the timing of protein ingestion (with resistance training) (84) promote muscle protein synthesis.

Absorption rates of amino acids from the gut can vary from 1.4 g/h for raw egg white to 8 to 10 g/h for whey protein isolate. Slowly absorbed amino acids such as casein (~ 6 g/h) and repeated small doses of whey protein (2.9 g per 20 min, totaling ~ 7 g/h) promote leucine balance, a marker of protein balance, superior to that of a single dose of 30 g of whey protein or free amino acids which are both rapidly absorbed (8 to 10 g/h), and enhance amino acid oxidation. This gives us an initial understanding that although higher protein intakes are physiologically possible, and tolerable by the human body, they may not be functionally optimal in terms of building and preserving body protein. The general, although incorrect consensus among athletes and bodybuilders, is that rapid protein absorption corresponds to greater muscle building.

From the limited data available on amino acid absorption rates, and the physiological parameters of urea synthesis, the maximal safe protein intakes for humans have been estimated at ~ 285 g/d for an 80 kg male. It is not the intention of this article, however, to promote the consumption of large amounts of protein, but rather to prompt an investigation into what are the parameters of human amino acid kinetics. In the face of the rising tide of obesity in the Western world where energy consumption overrides energy expenditure, a more prudent and practical approach, which may still provide favorable outcomes, is a 25% protein energy diet, which would provide 118 g protein on an 8000 kJ/d diet at 1.5 g ? kg-1 ? d-1 for an 80 kg individual (Table 2).

Little data exists on the comprehensive metabolic effects of large amounts of dietary protein in the order of 300 to 400 g/d. Intakes of this magnitude would result in some degree of prolonged hyperaminoacidemia, hyperammonemia, hyperinsulinemia, and hyperglucagonemia, and some conversion to fat, but the metabolic and physiological consequences of such states are currently unknown. The upper limit of protein intake is widely debated, with many experts advocating levels up to 2.0 g ? kg-1 ? d-1 being quite safe (102, 117, 118) and that renal considerations are not an issue at this level in individuals with normal renal function. http://www.humankinetics.com/eJourna.../pdfs/5642.pdf

That was interesting.

In the old days I would take whey protein pre-mixed to school and just drink it plain. These days I am trying to blend any protein powder I have with other things. It just seems taking protein powder by itself isn't the most effective use of it.

As far as post-workout goes it is true that muscles are screaming for nutrients. But is it only protein they want? I am thinking with blood vessels dilated to skeletal muscle essential fatty acids (EFAS) may also be beneficial for repair/growth at this time.

Now someone may point out that if pre-workout nutrition has enough EFAS in it then this could be ommited in the postworkout shake. That is something to consider too.

[NastyNally]

Very interesting article. So am I getting this right, a blend with casein in it would be superior to whey? Also, in order to fully benefit from whey in terms of muscle building we would have to take small "shot-like" doses of it every 20 minutes? That would be a pain in the arse.

[low blow]

Damn I always thought it was better to eat bolus amounts of protein vs. small amounts. I thought for protein synthesis to occur AA's have to be spikes...not just absorbed and maintained at base line?

[Pinckney12]

The short answer to this posted question is this:
Feel free to take in up to about 45 grams in supplement every 4-5 hours and tweak it from there. If you take more than 45 grams you may notice pretty foul-smelling farts. This is a sign of excess protein, so scale it back.
I found this out after talking to someone at a GNC store and it cleared up the mystery of the farts. I was taking 60-70 grams after a workout.
Hope this helps.

[Tree_Hugger]

Originally Posted by Phosphate bond

That was interesting.

As far as post-workout goes it is true that muscles are screaming for nutrients. But is it only protein they want? I am thinking with blood vessels dilated to skeletal muscle essential fatty acids (EFAS) may also be beneficial for repair/growth at this time.

Check out John Berardi's article "The science of nutrient timing" in the article section of this site. http://www.bodybuilding.com/fun/berardi54.htm
It really helped me understand more about this topic. The book that is referenced here is "Nutrient Timing" by Drs. John Ivy and Robert Portman.

As a point of reference for what the article and book contains, here is an excerpt from the article that discusses different "Phases" in which your body needs different nutrients:

"In the book, the authors refer to three critical times of the day in which nutrient timing takes on a greater importance. These times are known as the Energy Phase, The Anabolic Phase, and The Growth Phase. Since I like these distinctions, I'll use them here. However, I'll add another phase that I call, somewhat in jest, The Rest of The Day Phase."

I'll let you guys read the article rather than quoting a good portion about each phase and the nutrition involved.

Hope this helps.

PF

[precisou2004]

Originally Posted by RACKITUP

Personally its better to take in too much protein and waste some than not taking in enough, eat up shoot for 2g+ per pound BW and seperate over 6/7 meals

lmfao !!

I had to laugh at ur "sig line" heheh

[fredarn]

Originally Posted by SeaHawk22

Thats insane. Where did you hear that? Even on AS your body would not require 100 grams an hour. If you slept 8 hrs a day and were awake 16hrs that would be 1600grams a day. I dont care how much water you drink your kidneys would be f()cked. I am not trying to come off as an A$$ but it is dangerous if someone interprets your statement that it is beneficial to eat even half that amount.


SeaHawk22

If you eat more protein then you can use, it will be transformed to fat.

It will not kill you, or even harm you - as many people think. People previously thought that a high protein intake could harm the kidneys, but newer research clearly shows that thats not the case.

I personally eat 3 100 calories a day, and 310 grams of protein.

[RB12]

Originally Posted by fredarn

If you eat more protein then you can use, it will be transformed to fat.

that is ridiculous, please cite a source for this.

[leonidas300]

Originally Posted by RB12

that is ridiculous, please cite a source for this.

I think he means that any macronutrient will be stored as fat once maintenance calories are exceeded. This is true. Any time you have a caloric surplus those calories get stored.

[RB12]

Originally Posted by leonidas300

I think he means that any macronutrient will be stored as fat once maintenance calories are exceeded. This is true. Any time you have a caloric surplus those calories get stored.

while i do not disagree with you, i dont think he meant that (although I am sure he will say so). There seems to be a "common" misconception (based on a number of threads) that "if i get too much protein i will be fat" same misconception that leads too thinking carbs are evil