What Are Good Sources of Protein? – Speed of Digestion Part 3
Ok, somehow this mini-topic got a little bit out of control (I have a lot to say) so I want to wrap up the discussion on speed of digestion and move into the other topics that go into answering the question What are good sources of protein?
Whole Foods vs. Protein Powders
I finished up What are Good Sources of Protein? Speed of Digestion Part 2 with a short chart showing the estimated digestion speeds of various proteins, including some whole foods. As someone brought up in the comments, it’s unfortunate that there isn’t more data for whole foods because of the fact that, outside of athletes, most people are eating whole food protein sources, not protein powders, to obtain the majority of their daily protein.
And, in that chart, with the exception of an estimated value for tenderloin that seems impossibly high, most whole food proteins were on the slow end of the digestion scale. This actually makes perfect sense. Whole food proteins are generally contained within a matrix of connective tissue and such (e.g. think of the chewing that you have to put into eating meats such as beef, tuna, or chicken) and that alone will slow the process of digestion down. Basically, even without direct data, I’d expect most whole food proteins to be slowly digesting proteins.
Research using whole food meals find that amino acids are still be released into the bloodstream up to 5 hours after eating them; this certainly supports the idea that whole food proteins take a long time to digest. Other researchers have suggested that a given meal will maintain the body in an anabolic state for 5-6 hours so clearly whole food proteins aren’t digesting particularly quickly.
Basically, the majority of proteins that people who aren’t obsessed athletes will be eating are going to be slowly digesting proteins.
The primary exception that I’ve examined, of course, is whey protein which digests quickly; soy isolate is also a fast protein (another that I’ll mention briefly in a second is pea protein hydrolysate). Now, whey has some nice characteristics in terms of its amino acid profile (discussed in a later segment of this article), it may improve immune system function, and have other functional health benefits. Outside of athletes, life extension folks and the obsessed health types, I’m not sure that whey protein powder is going to make up a major source of protein for the majority of people.
However, this brings me in a very roundabout way to a related topic having to do with protein powders and the different forms that they come in.
Types of Protein Powder: Concentrates, Isolates and Hydrolysates
On this note, before moving on, I want to make a couple of quick comments about protein powders since, as usual, there is a lot of confusion, hype and outright lies being made about them. Quoting directly from The Protein Book:
Protein powders come in three primary forms which are isolates, concentrates and hydrolysates. Protein concentrates typically contain roughly 80% protein with 5-6% carbohydrate and fat while isolates may contain up to 90% protein. Hydrolysates are simply isolates or concentrates which have been pre-digested (digestion of protein is called hydrolysis) by subjecting them to specific enzymes. Practically speaking, you will typically pay the least for a protein concentrate, more for an isolate and the most for a protein hydrolysate. Because of the presence of free form amino acids in protein hydrolysates, they often have a more bitter taste than either concentrates or isolates.
In the last couple of years, there has been a real push by supplement companies for expensive (and often bitter tasting) hydrolysates based on the claim that they digest much more quickly than either isolates or concentrates and thus super-speed amino acids to just worked muscles.
Ignoring the question of whether faster is actually better (see below), there is the question of whether hydrolysates actually do digest significantly faster than protein isolates. Limited research is available and while one study showed that pea protein hydrolysate digested more quickly than other concentrates, this data can’t be applied to any protein except pea protein.
One study compared the digestion speed of whey and casein to their respective hydrolysates and the simple fact is that there was no significant difference in digestion speed. Quoting from the results:
The rate of gastric emptying for all solutions was found to fit an exponential pattern (r=0.92–1).Solutions were emptied at similar rates, with half-times of (mean ± S.E.M.) 21.4±1.3, 19.3±2.2, 18.0±2.5 and 19.4±2.8 min,for the whey hydrolysate, casein hydrolysate, casein and whey protein,respectively.
Basically, there was no real difference (maybe a couple of minutes faster for the hydrolysates) between whey isolate and its hydrolysate and casein and its hydrolysate.
Translation: there is no advantage to whey or casein hydrolysates in terms of digestion speed. None. Well, unless you think paying three times the price and accepting an often bitter taste is an advantage.
Which brings me in a roundabout way to the final topic of this series within the series:
Is Faster Digestion Better?
Although this question would pretty much never come up with regards to general health and nutrition, it is one that is relevant to sports nutrition (and as noted in part 2, older individuals may obtain beneifts from fast proteins). Is it better for protein to be quickly digesting or slowly digesting?
Of course the answer is context dependent and depends on what the goal is. For the majority of applications, I hope that readers get the basic idea that I think slower digesting proteins, or a mix of slow and fast are generally superior to fast proteins by themselves.
This is especially true for non-athletic applications where I think most should simply stick with whole food proteins most of the time anyhow; in the context of a mixed meal, that will mean that the proteins being consumed will digest slowly.
As I noted in What are Good Sources of Protein? Speed of Digestion Part 2, there is emerging data that older folks may benefit from spikes of amino acids in terms of offsetting age-related muscle protein breakdown. So that is clearly one exception to my general belief that slower or slow/fast mixes are best under most conditions.
Now, a recent trend in sports nutrition is to consume nutrients (carbs, protein) around the entire training bout, this often means before, during and after training. I actually spend about 35 pages discussing this issue in The Protein Book examining the most recent research and giving specific recommendations for both strength/power and endurance athletes in terms of when, how much and what to consume around training for different types of workouts. I’m not going to repeat that here, clearly.
As discussed thoroughly in that chapter, there is emerging data that a slow or mixed fast/slow protein following training is superior to a fast protein alone (I realize that this goes against what all of the supplement companies are saying but, as usual, they are taking research out of context to sell product).
Readers might simply refer back to my article on Milk: The New Sports Drink – A Review as research clearly showed that milk (a combination of whey and casein, that is a combined slow/fast protein) was superior to soy protein (a fast protein) for supporting muscle mass gains. Post-training, slow or a combination of fast and slow is simply superior to a rapidly digesting protein.
But that’s after training and folks are currently consuming protein before and during workouts these days. Under those situations, clearly a slowly digesting protein is inappropriate if for no other reason than having protein sitting in the gut digesting while you try to train is a good way to throw up.
For pre- and during-workout protein intake, I recommend a quickly digesting protein such as whey or a good soy isolate. That is one condition where, clearly, a fast digestion speed will be superior. Under most others, I feel that a slower digesting protein or at the very least a combination of slow and fast will give the best results.
There are other possible exceptions to the above, which I’ll come back to later in this series. As a primary example, some research suggests that hormonal impact of a fast protien like whey may blunt hunger better than slowly digesting proteins such as casein.
However, empirically, I can’t say I’ve seen this be the case: most report that casein (a slow protein) or milk protein isolate (a protein powder containing both whey and casein) keeps people fuller on a diet by sitting in the stomach longer. Again, I’ll come back to this in more detail when I talk about dieting.
And that’s that for speed of digestion. On Wednesday, I’ll look quickly at protein quality before moving onto the rest of the topics I outlined in the Introduction to this series.
Go to What Are Good Sources of Protein – Protein Quality
But i remember in the 90′s that right on the bottles of Designer Whey it said “269% better than regular whey!” or something like that. Lyle, are you saying that a supplement company lied to sell product?
The problem is that the only data showing and advantage to a WPH or WPI over WPC comes from in house data funded by supp companies. Cribbs, presented data that showed WPH was vastly superior to Casein, but it was poster presentation and it turns out that the AST VP2 product that was being advertised as a WPH wasn’t. I remember MuscleTech showing that its Nitro-Tech was better than regular whey but it’s just an el cheapo blend of WPI and WPC with milligram amounts of arginine (which will do nothing to stimulate NO production with all those competing AA’s entering systemic circulation) and ginseng. A closer look at the formula showed it had a sizable amount of creatine monohydrate in it which undoubtedly accounted for the difference, if in face there was one. The Designer Whey never had large amounts of whey peptides. I know Anssi Manninen is a big proponent of WPH but, to be frank, this is the guy who thinks the laws of thermodynamics are somehow inverted when you are in ketosis.
So some di and tri-peptides get absorbed intact and you save some time from your enzymes to do the job which sneaks the AA’s into the blood stream a few minutes faster. Given that WPH taste like ass and is more expensive, I’m going to pass.
I’m wondering what Lyle thinks of free form aminos vs. intact “fast” proteins (whey) pre workout. Even Michael Colgan begrudgingly switched to WPI pre workout even though he loved his TL Amino Fuel.
Common sense and good research makes me uncomfortable. Stop it.
Chris
I bet you can guess what I think of free form amino acids in this context.
Over-rated and useless would be a good start. Overpriced and horrid tasting would be a second comment. I see zero advantage to them over whey. I know a lot of people love them some BCAA’s and there is no doubt that leucine stimulates protein synthesis.
Here’s the problem, without the other aminos present, you still can’t build muscle. You don’t have the building blocks. If someone follows my full guidlines ala The Protein Book for pre/during/post workout nutrition, they will not only be getting plenty of BCAA but all of the other aminos that serve as the building blocks of skeletal muscle.
As well, nearly all of the BCAA work has compared BCAA to consuming nothing around workout; of course the BCAA is superior (to nothing at all). Someone needs to compare it to a whole protein and see what happens.
The long and the short of it is that nobody has shown that an (often theoretical) few minute difference in digestion makes an iota of difference in anything except the pocketbooks of supplement companies.
People get all fixated on this one thing absorbing 5 minutes faster than the other and are willing to pay 3X as much for that supposed benefit; I’m sorry, that’s not what determines whether or not someone is going to make progress or not.
Lyle
I don’t know if this is off-topic in this particular post ( I have read the last post as well):
Is there a protein supplement or source that you think people in training MUST use?
Or is it okay to just eat whole protein sources like meat, eggs, etc?
One reason I ask this is because for many people, consuming so much protein needed for muscle growth is often impossible in real life. Supplements provide that short cut. I do take whey, and I make casein at home and eat it daily. I don’t know what else I should be doing if whey protein after workout is all getting used for energy. Care to clarify?
I want to ask samething as Rambodoc.
whenever i read what the protien shake sellers say, they say its not something i must use but it can be helpful for me. and then they say something that puts me into difficult spot. they say that I need protein shake like whey proten, because they gets diegested into my blood stream the fastest (which is true…. right?) and they say it is very essential in order to get the MASS. I know that muscle grows during resting time from gym, (muscle don’t grow during you work out …etc), if drinking whey protein shake especially right after workout is the only way to be like one of those body builders, then i am missing out big time…. is there any replacement for whey protein supplement with whole food?
I am wondering about Coconut flour used in recipes. Friend can not have any type of wheat, etc. Severe reaction. Coconut flour might be a good substitute,among others. Coconut flour has a high amount of Protein. I know that Protein in any grains, plant products is not available to be used, except in Soy products. However, what about the Protein in Coconut flour? Is it available to be used when ingested?
John: I can’t speak to coconut flour specifically but the protein in all grain and plants foods is usable to the body. The idea that they are not is very out of date. So I wouldn’t be too concerned.
Hi
There is just one thing that make this whole discussion a bit unnecessary when it comes to this ( and I actually thought you were getting there in the very en of this page after discussing “IS FASTER DIGESTION BETTER?):
“The main reason is that most of the enzymes involved in the protein synthetic machinery of the cells and organs of the body have a low Km. They operate at maximal velocity when the intracellular amino acid concentration is between 10 and 30 μ M and basal levels of amino acids generally are much higher. Therefore, an acute increase in the plasma or intracellular concentration of the amino acids following the ingestion of a meal with a high protein content does not lead to a substrate activated increase in the rate of protein synthesis. An increase in the protein synthesis rate will occur after ingestion of a protein containing mixed meal as a consequence of the insulinotropic effect of protein/carbohydrate ingestion.
The Km for the oxidative enzymes (e.g. urea cycle enzymes, dehydrogenases) is much higher. This implies that the rate of amino acid oxidation and urea production increase rapidly following ingestion of a meal with a high protein content. The main effect of an acute increase in the protein content of the diet, therefore, is increased amino acid oxidation when the protein intake exceeds protein requirement.”
So why bother about its speed when it all goes to oxidation???
All the best
mikael
Ok, I’ve read through this entire article and didn’t find the answer to my underlying question. If I weigh about 205 pds and my lean body mass is about 175 pds, we know I need about 200 – 225 grams of protein per day. Is the old adage true that you can only digest approximately 40 grams of protein per meal and if so, is it best to eat 3 of those meals in some sort of protein powder because of the digestibility factor? As I read this article, I am still confused about once you eat a low carb, high protein meal, and you are giving it 3 hours to digest, but it has not fully digested (it’s made it out of the gut, and into the intestines) and then you add another meal on top of that, will it digest the full 40 grams of protein on that second meal, when it is still digesting the first meal?
Is this question clear?
Larger amounts of protein just take longer to digest, the idea that you can only digest ‘X per meal’ is basically nonsensical. If you eat a ton of protein, it just take hours and hours and hours to be digested.
If you stack one meal on top of another, the second will just sit in the stomach until it can move through.
Thanks for the post back, just so I’m clear, I could eat 4 meals, each with 50 grams of protein, and still digest and use all 200 grams? It sounds like you think this isn’t the smartest approach. What are your thoughts to maximum digestion of protein as far as grams per meal and how often? Sorry if I sound like a newby, I used to be huge into nutrition, but, have taken a few years off….
Was anybody surprised that milk was better than soy? Was anybody even fooled that this was a comparison of fast vs fast/slow?
What do you think it was a comparison of then? Because contrary to bro-wisdom, soy is not the shit poor protein that most think.
And note that other research still supports the superiority of slower or fast/slow proteins to pure fast for mass gains.
I was wonder if you touched on bioavailability at all? Although no one has responded since 09 so…
Whey Protein 104+
Egg 100
Milk Protein 90
Fish 80
Casein 77
Soy 74
Beef 70
I thought I had somewhere in the series and I definitely did in the book. Sufficed to say that the above (which I think are really supposed to represent Biological Value) are incorrect.
sorry if I mis-spoke and I realized that bioavailability is a term used to describe the ease with which nutrients can be absorbed, and thus utilized by the body and biological value is a measure of protein quality, assessed by how well a given protein supports nitrogen retention in humans but what I meant to say is did you touch on how the BV is possibly one reason people choose whey? not to mention increased glutathione expression…although since most people mix there whey in milk doesnt it render this whole thing moot? (LOL,jk). thanks.
Thanks. Exc review.
Although you reset at the end, calling whey ‘fast’ and casein ‘slow’ after you explained that both digest in 1 hour.
All this appears to support six small meals to even flow nutrition, etc.
Read it again and pay attention to the actual words. Both casein and whey hit the bloodstream at the same hour mark. But their overall kinetics are totally different. Seriously, please stop reading my site and buy Hooked on Phonics and learn to read.
Any chance you could stop yelling and being mean to random people on the internet long enough to answer my 6 month old question? Nevermind actually you seem like a prick and I’ll save myself the prick like answer. Good day.
just trying to get my head totally around the whole protein supplement thing for the purpose of gaining weight. At 55 I am finding it very difficult to maintain lbs. I have a very fast metabolism and am very active. So far I get the protein absorbtion rate stuff but each individuals food absorbtion rate must be a factor too. eg/ If my system process’s an 8 ounce protein drink with 30 grams of whey isolate quicker than someone elses, is it not likely that I miss out on a lot of the protein? I have also read some interesting info regarding aspergillus niger and aspergillus oryzae as “boosters” to protein absorbtion. Any comments regarding that?
I’ve seen little to nothing looking at individual differences in protein digestion/absorption rates. They may exist but no-one has looked at it experimentally. There is research that older folks seem to respond better to faster proteins in terms of stimulating an anabolic response and, in that regard, they do differ from younger individuals.