wow, im not sure if i can find that exact research i read years ago. but i was browsing around and found these:
a quote from that link:
"protein requirements for sedentary and strength athletes were found to be 0.69 and 1.4 gÂ·kg-1Â·day-1 respectively."
to translate i will use my bodyweight of 210, 1.4g/kg = 138grams (rounded up) = 0.64gr/lbs
yes one could say that this quote references strength athletes and bodybuilders are not strength athletes but mass builders. man i hope not. that is splitting hairs something wicked. but i guess we will cross that bridge if we need to.
i do like this quote as well:
"It has been suggested that strength training athletes with greater experience become more efficient at protein utilization"
and i wonder if it is true.......
as you read more of that link you see several times they reference high protein amounts at 1.5-2.2gr/kg of bodyweight. which is about half what you will find in bodybuilding mags. why does research say one thing and bodybuilding mags another.......
now we also do see that the higher protein intake shows an increase in strength and mass and i was never doubting that at all. my statement was to show that it is not a requirement for an increase at the levels he was taking. as the OPs levels on protein intake are even higher then the high amounts used in the several research studies and the participants were gaining strength and mass at lower levels i would not be concerned. basically, what i stated still holds true according to that research.
and to reference a comment earlier from another poster. his experience says otherwise. this first link which shows experience from potentially hundreds of people shows that i am right. the good thing is, it also shows that higher protein can increase results, so you are partially right if you looked at it from a maximal or optimal protein intake to garner results in comparison to a minimal protein intake to garner results. and to restate, i was showing a potential minimal intake to garner gains and not a maximal or optimal level.
here is another quote i like:
"In a recent review Milward summarized this issue by stating that "NB studies need to be conducted in individuals in energy balance, because if energy requirements are underestimated then protein requirements will be overestimated, and vice versa ." The rationale is that a decrease in energy intake causes an individual to increase the utilization of stored amino acids for fuel "
notice how it shows that if you eat less overall calories more amino acids will be used for fuel. meaning you will need to eat more protein. this kind of goes along with my original post that stated as long as you eat enough total calories/food you dont need so much protein.
and to continue with this line of thinking:
"According to their calculations a 90 kg man (approximately 200 pounds) with moderate physical activity, consuming 2700 kcal per day (30 kcal/kg) would need 123 grams of protein daily to achieve zero nitrogen balance. Increasing these calories to 4000 (45 kcal/kg) would lower his needs to approximately 80 grams daily. "
see. more total calories, less protein needs.
and another quote:
"In fact Tarnopolsky et al.  found that protein synthesis increased from low (0.8 g/kg) to moderate (1.4 g/kg) intakes. While there was an 8.6% increase from moderate to high (2.4) protein intakes, these results did not reach significance. The authors suggested that this non significant trend appears to support the suggestion that the real protein requirements of athletes were closer to the 1.8 grams of protein per kg of bodyweight daily."
protein synthesis at 1.4g/kg or 0.64gr/lbs. yep, that low. and increasing protein intake by 58% only saw an increase in gains by 8.6%. talk about point of diminishing returns. make me think that most bodybuilding mags are using maximal protein levels and not optimal protein levels.
and to bring up BB zines you need to bring up the fact that many if not all pros use vitamin S which we know changes ones body enough to that the results are not common. add in the fact they are genetically on the end of the spectrum to the other 99+% of the human population you have to wonder how well their diet and workouts will work for us lower humans, lol.
here is another link and i will keep the comments much shorter:
on thing to notice is how groups were seeing an increase in muscle mass with better timing of protein intake not just an increase in protein intake. and that supplementation post exercise was between 10-25gr.
i bring this up as the first link also mentioned quality of protein and timing as a reason for variance in research results.
and one quote from that link:
"In their review of dietary protein intake in humans, Bilsborough and Mann30 state that an 80kg individual could deaminate up to 301 grams of protein per day. At the levels previously cited7,9,11 as eliciting maximal rates of protein synthesis, amounts greater than 300gm per day would be absolutely unnecessary."
that would someone taking in 1.5gr/lbs of bodyweight of protein a day. they showed it to be unnecessary. and many BB 'zines i have read with no backing of science will state you need(!) 2+gr/lbs of bodyweight to gain mass. oops. someone is wrong here.