how many grams of protein can a body utilize before it winds up as waste? I have heard one can only take in 30-50g a time that the body will actually use. any thoughts on this??? tam
Well as luck would have it, I was part of a study when I was in the USMC that centered around that subject. It was conducted by UCLA and I was undergoing a rigerous training program (USMC sniper school) and asked to be part of the study. It was designed to monitor nitrogen retention, muscle waisting and uric acid build up from low, moderate and high protien meals. There were several test groups and mine was the high protien group (I requested this for obvious reasons) There interesting thing was that the high protien meal was devided into two servings and consisted of both liquid and solid foods with minimal carbs and fats. Although the study was looking at other aspects of diet and how macronutrient ratios effected recovery after trama, I was interested in weather my 100 grams of protien per meal were wasted or not. Over the 8 weeks of the study I stayed in a positive nitrogen balance, showed no excess protien problems, kidney and liver enzymes functioned normally etc. After the study I spoke to several of the research students and we came to the conclusion that there was no protien waist because my body was in NEED of the extra amino acids for repair. This led me to believe that if the need was great enough the body would utalize whatever it needed no matter the ammount or number of feeding it was broken down to. Further study in the area concured with our findings and although not optimum the body will use over the normally prescribed 30 grams if it need it, and maintain a positive nitrogen balance to boot. Again this is not the best way of doing things because of other metabolic factors and function. Think of it this way, primal man (and woman) would go for days eating nuts and roots until they found that nice meaty wollymamoth. Then they would gourge themselves on meet (protien) and after it was gone, back to roots and berries. Point is our metabolic functions are not all that different now, and we have 100 million years of evolution that dictates how our bodies function. Science has just allowed us better options for more effecient results and breaking your 250 grams per day into smaller feedings allows for a more effecient use of nutrients, BUT just because you eat 50 grams or 100 in a sitting does not mean you waste it all IF THE NEED IS PRESANT! If not the body will effectively rid itsself of the excess and unless you have some other health condition, your fine. Hope this helps.
Sully, Sorry I didn't get to see this message sooner. I would've enjoyed coming to the show even if just to meet, and place a face with the name. While I do keep up online with what's happening with board members, their progress and their placings...I don't typically follow the show schedules. If you get a link to any pictures from the show, I'd love to see them. I do know of some locals that were most likely on stage.
I don't have extensive research to back up my findings, but the way I have understood things, the body can only use about 30-50 g of protein at a time as an amino acid source. When you have an extreme need (i.e. after heavy training) this may increase slightly, but I think it is a good rule of thumb. The rest of the protein is converted via gluconeogenesis into glucose for energy. However, this process requires energy, which is why you can eat more calories on a high protein diet than on a lower protein diet. Since protein won't raise your insulin levels though, it provides somewhat of a "back door" to glucose production without triggering an insulin spike.
In conclusion, if you eat more than 30-50 grams per meal, the excess is not "wasted" per se, but it may be used for energy rather than as an amino acid source.
I am with you there, and that is where "OPTIMAL" comes into play. Now no where near 100% of the 100+ grams of protien used went to muscle building, but muscle spairing. Muscle spareing involves other factors and there is a need for some conversion to glucose or the body and brain would NOT be able to function. Now my example is in NO WAY suggesting we eat one or two meals of 100-200 grams of protien per day and call this effective. My point is that in time of extream stress, and longer fasting stated the conversion to glucose is much lower as the body prioritizes its needs. This is for survival reasons only, and mandated by our genetics. Now does this mean in my case 90 grams of the protien was utalized for muscle building...first there is no real way to know for sure how much and second NO but 100% was used for muscle spairing. My points conincide with yours, 30-45 grams split into 5-7 feeding is adaquate and optimal due to conversion ratios. So your 100% correct, but given certin factors Thanks Dcandy for pointing out the obvious. I have a tendency to throuw things out there, but forget to review the optimum or norm. By "watching my back" we can provide the proper information with the scientific solid backing. My points above are just a example of the extreem states the body can go in and compinsate for and not a reccomendating for ideal dieting. Dcandy, EXT, Fitdoc, VAmaddog, Aram, Broc and others provide all of us with a mountin of wisdom and I thank you all.
One correction: insulin IS secreted in response to protein, ie, amino acid intake. Insulin release is also stimulated by fatty acids. As the most anabolic hormone in the human body, insulin enhances lipogenesis and protein synthesis.
Sulcop, could you provide more information on the study, along with a reference to where I can find the paper, or at least abstract.
I experimented for a few months on a 2 meal diet plan (spaced 12 hours apart) after having looked at all the meal frequency research. I basically ate 1.5g protein per lb, spread in 2 meals (150g protein per meal), along w/ moderate fats and fiber to slow digestion. (Technically 3 meals on lifting days, small protein meal 1-2 hrs pre-training, large meal immediately post-workout, then the next big meal 12 hours later) I noticed no increase in muscle loss having done this, and I felt fine throughout.
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