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(Aaron_F @ Jun. 07 2007,05:00)</div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE"><div>
(John Steel @ Jun. 07 2007,17:57)</div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">Aaron_F:
"I will put it very simply for you,
I dont care if the quote is from this very site.
The pool of amino acids is not just muscle."
I will put it very simply for you.
I'd like to see some of this information for myself and I'm sure others would as well.</div>
I take it writing a PM entitled "Expert, my ass" was not enough for you? Or would you prefer that I cut and paste commetns from bryan as an indication of my knowledge?
Do you want evidence of meal frequency itself, or the digestion rate of protein from mixed or single sources? or maybe something different?
When protein intake is low, frequency becomes more important. But this in the calorically restricted enviroment with sub=rda levels of protein. its a non-pubmed article so I cannot online articles for that. Digestion rate of foods, there are a number, a review paper from Neill Mann, hes a nice guy from RMIT in Melbourne
A review of issues of dietary protein intake in humans.
Bilsborough S, Mann N.
B Personal Pty Ltd., Melbourne, Victoria 3001, Australia.
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 x kg(-1) x 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 x kg(-1) x 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 x kg(-1) x 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 x kg(-1) x 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).
take careful note of the rate of amino acid uptake from the gut. 1.3-10grams per hour, which is highly likely on the low side, because its based off research that included small doses of protein rather htan maximal as well as being uncorrected for bodyweight, but it provides a reasonable idea of what is happening in the gut. If you provide a large meal, ~50g protein, the body cannot digest this quickly, so due in a large part to something called hte ileal (and duodenal) brake, the body slows ejection of the mixture from the guy to allow the intestines the ability to digest as much amino acids from the mixture as possible. Even eating as little as 30g of protein from whey, amino acids are still appearing 3-4hours later.
This once again supports what I claimed above, if you are eating low doses of protein, eating frequently becomes more important.
In terms of maintaining a blood level of amino acids not being the best. This is a piece from Robert Wolfes group, that was looking at IV amino acids, a somewhat artificial enviroment, but gives us an indication of maintaining amino acids.
Latency and duration of stimulation of human muscle protein synthesis during continuous infusion of amino acids.
Bohé J, Low JF, Wolfe RR, Rennie MJ.
Metabolism Unit, Department of Surgery, University of Texas Medical Branch, Shriners Burns Hospital, Galveston, TX 77550, USA.
1. The aim of this study was to describe the time course of the response of human muscle protein synthesis (MPS) to a square wave increase in availability of amino acids (AAs) in plasma. We investigated the responses of quadriceps MPS to a approximately 1.7-fold increase in plasma AA concentrations using an intravenous infusion of 162 mg (kg body weight)(-1) h(-1) of mixed AAs. MPS was estimated from D3-leucine labelling in protein after a primed, constant intravenous infusion of D3-ketoisocaproate, increased appropriately during AA infusion. 2. Muscle was separated into myofibrillar, sarcoplasmic and mitochondrial fractions. MPS, both of mixed muscle and of fractions, was estimated during a basal period (2.5 h) and at 0.5-4 h intervals for 6 h of AA infusion. 3. Rates of mixed MPS were not significantly different from basal (0.076 +/- 0.008 % h(-1)) in the first 0.5 h of AA infusion but then rose rapidly to a peak after 2 h of approximately 2.8 times the basal value. Thereafter, rates declined rapidly to the basal value. All muscle fractions showed a similar pattern. 4. The results suggest that MPS responds rapidly to increased availability of AAs but is then inhibited, despite continued AA availability. These results suggest that the fed state accretion of muscle protein may be limited by a metabolic mechanism whenever the requirement for substrate for protein synthesis is exceeded.
This doesnt quite give us an idea of what happens following a meal, but some early data presented by Natural Bodybuilder Layne Norton, who is studying within Doug Laymans group indicates that while amino acids are raised 3hrs following a meal, protien synthesis drops off relatively early*, matching the IV study listed above. Eating large meals routinely over the course of a day, maintains plasma amino acids at a high level all of the time, meaning that protein synthesis is blunted. Obviously this is not the rate limiting piece, but may be something that is useful to manipulate in order to speed gains towards the natural maximum.
* 694.6 Translational controls of muscle protein synthesis are delayed and prolonged associated with ingestion of a complete meal. L.E. Norton, D.K. Layman, P.J. Garlick, D. Brana, T.G. Anthony, L. Zhao, S. Devkota and D Walker. Univ. of Illinois, Urbana and Indiana Univ. Sch. of Med Evansville. This is unpublished at this point, the abstract should be available from FASEB, but htey are typically very slow to get the abstracts available from FASEBJ.com</div>
Don`t bother with him. Asides from the whiny ass PMs(that are quite entertaining, mind you, they`re like internet tough guy to the max), there`s nothing fun about this latest trollish incarnation(there seems to be a lot of em here these days). Say, wanna trade PMs?Mine are with profanity, homophobia and stuff...and of course, the best, Internet threats.
