In terms of daily caloric intake we know that 1g protein = 4 calories. But as most everyone here is aware of, not all proteins are equally absorbed by the body. Consider this: Two hypothetical lifters at the same weight/experience/etc. both consume 300g of protein a day. Lifter #1 derives 100% of his protein from soy sources while lifter #2 derives 100% of his protein from egg sources. The lifter who's getting all his protein from soy products can't possibly have the same protein utilization as the lifter who gets his protein from eggs. If you do the math, lifter #1 (all soy) winds up absorbing only 148g of the 300g of protein consumed whereas lifter #2 (all eggs) winds up absorbing 264g of the 300g of protein consumed during the course of the day.
I've come up with a few questions for discussion:
1) When counting your daily protein grams to make sure you're getting a sufficient amount, for accuracy's sake, wouldn't it be necessary to multiply the net amount of protein in each food by their absorption percentage (refer to chart below)?
2) For supplements like whey isolate, & L-glutamine wouldn't the percentage absorbed be around 99% or so (so long as these aren't combined with other proteins being consumed simultaneously)?
3) How can you find out the maximum amount of protein you can absorb in one meal? I know this increases directly after a workout & with the use of juice, but is there some rough formula based on, say, bodyweight?
(the chart below is fairly common - FYI I pulled it off http://www.columbu.com/nutrition/protein.html )
The protein utilization rate of some common foods follows.
Food NPU (net protein utilization)
Eggs 88%
Fish 78%
Dairy products 76%
Meat 68%
Soybeans 48%
Natural brown rice 40%
Red beans 39%
Coconut 38%
Nuts 35%
White beans 33%
Maize 25%
Whole wheat bread 21%
White bread 20%
