How Much Protein Can You Absorb Per Meal?

[Mehdi]

I consider all of this "The body can only use X grams per Y" as a lot of nonsense. First and foremost, it makes no evolutionary sense (how I've been looking at a lot of physiological processes lately). That is, our ancestors did not eat protein in small amounts throughout the day. Yet, anthropological studies show that they had more muscle and bone mass than most of us. Rather, they were more likely to eat a ton of protein after a kill, and whatever amount they got from vegetables and such the rest of the time. Massive protein intakes at once were more likely the norm during 99% of our evolution than not. This means that our guts evolved to handle it. In addition, when you start looking at digestion and such, you see exactly that: even with massive protein loads (I vaguely recall they've looked at like 1.5 g/kg of beef all at once), digestion still stays very high (on average 90-95% for animal proteins meaning you're losing at most 10 grams of protein/100 grams ingested). The body can digest/absorb pretty much anything you throw at it. You won’t be pooping protein if you eat 35 grams at a sitting, is what I'm saying.

Now, a slightly separate issue might be one of how much protein (amino acids really) the liver can handle at once. If the recent studies on whey vs. casein have pointed anything out, it's that flooding the liver with amino acids at a high rate leads to increased amino acid oxidation (burning) in the liver. I suppose it's conceivable that high protein intakes at any given meal could be having this effect. I suspect it depends on the source of the protein (whole food which digests slowly vs. protein powders which digest faster). That is, consuming, say, 50 grams of whey protein at once might lead to more waste (mainly as amino acids oxidized and then converted to urea) than 50 grams of casein or beef. But that's more an issue of speed of digestion than amount per se.

In terms of supporting optimal growth, an interesting discrepancy actually occurs here between the studies on our ancestral diet and the protein needs of athletes, but nobody has an explanation yet. Good studies by Peter Lemon, Mark Tarnopolsky, etc. support a maximum protein requirement for natural lifters of about 1.8 g/kg (a little less than the 1 g/lb that bodybuilders have used for years). But studies of our ancestral diet suggest protein intakes as high as 2.5-3 g/kg. Nobody is quite sure if this protein intake was simply a side effect of the diet our ancestors followed, or if it had some actual benefit.

Finally, I think the whole 30 g/meal (or whatever) thing can't possibly apply to everyone. I mean, at the low end, figure a 210 lb lifter is eating 210 grams of protein per day. If he's limited to 30 grams/meal, that means seven meals minimum per day. Obviously, if there is some limit to protein absorption/assimilation/digestion/utilization (and I don't honestly think that there is) it's going to be related to body mass: a larger individual needs more protein and would be able to utilize protein in larger amounts than a smaller person. Ultimately, my hunch is that the whole '30 grams per meal' (or whatever) thing came from one of two places:

i)Early supplement companies trying to convince lifters why their protein product (containing 30 grams) was better than others. I remember one company pulling a scheme like this, when their product contained like 37 grams of protein, they wrote that 37 grams was the maximum that could be absorbed. When they bumped it to 42 grams of protein per serving, 42 became the magic number. Ah, advertising.

ii)Bodybuilders rationalizing what they had already decided to do. That is, you frequently see bodybuilders and other athletes finding a strategy that works (i.e. eat protein at intervals throughout the day) and then making up physiological rationalizations afterwards. It wouldn't really surprise me if that weren't the case here. Of course, if anybody has a single piece of peer-reviewed research supporting this 30 grams myth (everybody seems to claim to have seen it but nobody seems to ever have it; it's like those friend of a friend stories)

[nburge]

Seems like a very sensibly written article. I didn't think you were a big fan of research/scientific studies though, Medhi? At a guess I would tend to agree, there there is no biological rationale why your gastrointestinal tract would be unable to absorb vast amounts of protein at once. The liver is there to co-ordinate the subsequent usage of ingested chemicals, so it may well choose to oxidise those if there is no immediate need. I would be very surprised to find out that the liver was doing this if another part of your body (muscles) were crying out for amino acids as muscle building blocks, though.

I have been wondering about this for a while now - personally I tend to ensure the meals on the day I'm training (I train in the morning) and the evening before are PACKED with protein, and worry less about my intake over the weekends and on non-training days. I have no idea whether this is backed up by science though.

Very interesting post though - thanks Medhi.

[rejuvenile]

Your right the about the whole eating large amounts of protien, but they did more than just 135mins (3x45) of intense lifting(work) a week right ? i dont see any barbells or starting strength books laying around 1000 years ago or even now in many aborginal cultures globally... It could have have taken days for them to kill and track a larger animal to its death and thats with the advent of arrows and that was a newer piece of technology. Also travelling everthing thing was done on foot were talkin and extreme number of kilometers a day, should i add this as cardio session when i train? No tap water how much water was in that ancestral diet your talking about ? And theres so many differening cultures my ancestors were from the interior of North America but theres coastal culture aswell as african cultures that still exist like the san, they are tiny people. There diet based around a belief of not having any surplus and they live hand to mouth. Can we as a western nation even start to begin what living hand to mouth is ? And what not having a surplus is like? Based on the san i should share and eat all the food that i own and not have any surplus and sorry no frigids in ancestral diet either. I know with my native culture i've asked alot of elders of there ancestors eating habits, and it varried fruits and carbs yes real complex carbs (oh no naturally occuring sugars thats SUGARS now he said to much) were in that diet and sometimes only carbs were consumed and wild game, game that was untouched by man and his additives and pollutants. i dont think ive heard them say that eating every 2.5 -3 hours or having macros played a larger role in there thought process about how to eat and when to eat. There are lots of feasts in tradional in my culture and there is lots of fasting as well. I don't know to many of my white friends that fast for 4 days or more with no food and water for spritual reasons. Should you fast aswell maybe if you become stronger spritually you'll become strong physically? Meh just a rant when you bring up stuff on what we used to be like remember that their entire way of life differed from our current way of life. I dont eat 600g of protien in one sitting because i'm not worried about dieing from starvation. Maybe the thought of dieing from starvation played a role in making them stronger?

[Jcraig]

Make an attempt at breaking your post into paragraphs if you have a lot to say. While you may have had some good points, it's a pain in the ass to pull them out of that wall of text.

[tomtomtom]

If someone writes an article and it's supposed to be credible, it should contain propper references and not hunches that the author has. The arguments are reasonable, but you need to back it up with more than hunches and common sense

[Mehdi]

If someone writes an article and it's supposed to be credible, it should contain propper references and not hunches that the author has. The arguments are reasonable, but you need to back it up with more than hunches and common sense

Check out his book, plenty of science in it. Lyle McDonald's Protein Book

[tomtomtom]

Right... so he probably has his references in check then, you on the other hand, did not. I'm not trying to argue (well, I probably am, but still...), but the point here is that one should include references so people can verify what they read. I think a lot of forums have a lot of know-it-alls that spread their "knowledge" without having a sound theoretical background. I thought you just posted an article from some guy...

[Mehdi]

:)

Right... so he probably has his references in check then, you on the other hand, did not. I'm not trying to argue (well, I probably am, but still...), but the point here is that one should include references so people can verify what they read. I think a lot of forums have a lot of know-it-alls that spread their "knowledge" without having a sound theoretical background. I thought you just posted an article from some guy...

You know this blog is about common sense > science. Nowhere do you see me include references in articles. I'm not playing that game. You want references: there out there. I'm not here to convince people. Just sharing my opinion.

[katarina]

Lyle McDonald: "But studies of our ancestral diet suggest protein intakes as high as 2.5-3 g/kg".

This surely was not on a daily basis. As he has pointed out, our ancestors (and here I think of hunters and gatherers) used to have a large portion of protein when they caught a prey and then spent days without or with minimum protein intake. Sort of "protein intermittent fasting".
However, I agree with the message: the whole myth has most probably been launched by supplement manufacturing companies in order to push their products on the market.
I agree with rejuvenile´s post. Traditional folks preferred animal fat to lean protein. And when protein was ingested it was always fatty meat. To the contrary of the modern diet habits, where mostly lean meats are consumed, they preferred the whole animal (i.e. organ meats, brains, guts, lungs, eyes, sweet-breads, etc.), not because its nutritional value but because it was what was available. Even the traditional Innuit, one of the few truly low-carb cultures, consumed roughly 70-80% fat, 15-20% protein, 10% carbs.

[xsinner]

Katarina said
Traditional folks preferred animal fat to lean protein. And when protein was ingested it was always fatty meat. To the contrary of the modern diet habits, where mostly lean meats are consumed, they preferred the whole animal (i.e. organ meats, brains, guts, lungs, eyes, sweet-breads, etc.), not because its nutritional value but because it was what was available. Even the traditional Innuit, one of the few truly low-carb cultures, consumed roughly 70-80% fat, 15-20% protein, 10% carbs.

Does that mean the pig's feet with collard greens are ok? Just kidding. But I do have a serious question?

Pre workout mornings. If I eat 4 eggs, 10 oz of white chicken, 1 cup of mixed veggies and .5 cup of grated cheese and a banana for approx. 47gr fat, 34gr of carbs and 67 gr of protein.
Then drink a iso whey and milk drink with 8gr of fat, 11 gr of carbs and 28 gr of protein .5 to an hour after breakfast and .5 hour before workout am I just overloading with protein and basically wasting my money? Or am insuring that my body has a plenteous supply of protein?

[mjh]

I think you have nothing to worry about, and many gym-goers would do well to eat a similar breakfast.

[fsaekar]

Lyle's argument concerning our "ancestors" is built on speculation, not observation. He supposes a few things. He suspects a few things. He has a "hunch" of where the 30 g/meal idea came from, but he doesn't really know. And the one scientific study he does quote contradicts him. So I don't view Lyle's thoughts as solid evidence that 30+ g/meal can be absorbed.

I'm going to follow the AD this summer. If it works, it works. If it doesn't, it doesn't. No point in determining my diet based on vague speculation and "hunches".

[SalohcinUK]

I think everyone concerned with protein based diets should read the following:

http://www.humankinetics.com/eJournalMe ... s/5642.pdf

This is probably the most thorough analysis of protein related diets. The ammount of protein you can safely consume in a 24 hour period is very high, even when considering the effect on the liver. What is more interesting though, is how many hours it will actually take you to digest that protein. Raw egg is the slowest digesting protein you can eat, at only 1.3 grams an hour. Whey however can pull in 8-10 grams an hour.

[potto]

I think everyone concerned with protein based diets should read the following:

http://www.humankinetics.com/eJournalMe ... s/5642.pdf

This is probably the most thorough analysis of protein related diets. The ammount of protein you can safely consume in a 24 hour period is very high, even when considering the effect on the liver. What is more interesting though, is how many hours it will actually take you to digest that protein. Raw egg is the slowest digesting protein you can eat, at only 1.3 grams an hour. Whey however can pull in 8-10 grams an hour.

Interesting article this one. Might switch around my late night milk protein with my morning raw eggs as a result.

Also interesting that the quicker acting sources of protein actually aren't that efficient at being utilised in full.. food for thought.

[schnupi]

Why on earth would you want to eat raw eggs? Was it not already proven many times that your body can absorb less than half of the protein when you eat a raw eggs vs a cooked egg? .. maybe through in a raw egg in with your late night snack to slow it further down.

I would never consider raw eggs though as a good protein source.. just because rocky did it, doesnt mean its right