The body can only digest about 30g of protein in one sitting/meal. Take for example a bodybuilder who eats 6 meals a day and takes in 300g of protein or 50g per meal. Their body is only really digesting and utilizing 180g of protein, 120g is wasted. Also, too many people get caught up in the 2g per pound idea.
The RDA is .8g per pound of lean body mass, but the RDA doubled the actual recommendation of .4 (to cover any deviation, and be on the safe side). So, even at the published RDA you are still above the maintenance level and can build muscle.
I beg to differ.
The body is not 100% efficient at processing anything we eat. That's why we have to use the restroom. Furthermore, building muscle mass is the LAST thing on the body's "to-do" list. There are vital and important functions that the body performs and it utilize protein (and other nutrients) to do that. Only after all of that is done, does it turn its attention to building mass.
Plus, you make the assumption that the body cannot become more efficient at metabolizing protein. I can tell you from personal experience that's not true. I've gone as high as 500 grams of protein per day. But, that was several years ago with a faster metabolism for a limited period of time.
The RDA is for couch potatoes, which most bodybuilders are not. If the body needs extra nutrients to build mass and they are not available, I don't care what the RDA says, YOU AIN'T GROWING, PERIOD!!!!
I can get bigger eating fewer calories than I did 10 years ago. That's one of the reasons I've cut back my usage of my favorite weight-gain powder, N-Large[sup2[/sup]. I needed more calories to reach a certain size. Once I got it, maintaining it (and growing) doesn't require that I inhale as much food.