I just returned from donating (well, selling actually) my plasma at a BioLife Plasma services center. Part of the process for qualifying, in addition to a lengthy health questionnaire and brief physical exam, is a blood protein level screening.
There have been statements made by many folks putting supposed caps on the amount of protein the human body can process, as if all bodies were identical. The founder of one nutrition company recently even stated that the body can only process 10 g of protein per hour.
Related: MTS Machine Whey Protein Powder: Amazing Taste, Amazing Quality
Some people still cite the antiquated and arbitrary 26 g of protein per meal that some ancient pseudo-study produced. Such statements are ridiculous on the face of them merely on the premise that bodies, metabolisms, activity levels, goal specificity, kidney health, and so many other variables make blanket statements of this nature impossible.
How Much Protein Do I Need?
The general nutrition guideline for protein intake from most nutrition texts and physical training or personal training programs is taught as .8 g per kg of bodyweight. Even the BioLife information itself recommends 50 80 g of protein per day, which is the same as the general nutrition guideline.
Granted, sports nutrition texts and studies, which are typically far more specific than general nutrition sources, allow for the increased protein needs of performance athletes, and will raise the number from 1g to 1.5g per kg of lean mass. Additionally, recent studies show that increased protein intake is beneficial to slow the age related effect of sarcopenia (muscle tissue atrophy) especially among the elderly (over 50).
Personally, I consume 1 to 1.5 g of protein per lb. of bodyweight. I measure purely by my bodyweight, not by my lean mass. And I know many bodybuilders whose protein consumption is even higher. To put my consumption in perspective by doing some quick math, that puts my protein intake at nearly three to four times the general nutritional guideline (1g/lb. = 2.2g/kg, and 1.5g/lb. = 3.3g/kg.).
Even at the increased recommended level for performance athletes, my protein numbers still put me well over two times the recommended daily intake. At age 53, and working with heavy weight daily in my feeble attempt at gaining muscle and staving off the aging process, my protein consumption would still be considered well above most guidelines, and exponentially higher than normal.
The acceptable range for blood protein concentration to qualify as normal is 6 to 9 g per 100 ml of blood plasma. With my protein consumption, you might expect my level to have exceeded the normal parameters, or at least to be on the upper end. However, this was not the case.
My protein concentration was squarely in the middle of the field at 7.4 g/100ml. I spoke with the medical technician; he said that many of the younger donors who train regularly and claim to be on high protein diets are at the low end of the scale at 6.2-6.4 g/100ml.
Protein Assimilation and Muscle GainsThe takeaway is that the human body is an adaptive machine with many variables. If you are training to gain muscle mass and putting sufficient demand on the muscles for the protein synthesis needed for hypertrophy, your body will process even inordinately high levels of ingested protein.
I am routinely below 14% body fat without being overly concerned with diet. I meet my protein needs and fill in the rest of my calories relatively healthfully. My total caloric intake is typically on the upper range of both the World Health Organization and Harris-Benedict Resting Energy Expenditure (REE) recommended guidelines.
The next time someone tries to foist some fabricated fiction as fact about protein assimilation on you, consider my experience. While acknowledging the purely anecdotal nature of these observations, they are still evidentiary and well supported by this oft hidden and underemphasized statement in nutrition texts and studies which says "the exact upper limit of protein intake that is safe and effective for athletes has yet to be determined" (Burgoon).