I thought you guys would like to see some research done by a long time friend of mine:
Antonio, J., Peacock, C.A., Ellerbroek, A. et al. The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals. J Int Soc Sports Nutr 11, 19 (2014).
The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals - Journal of the International Society of Sports Nutrition
4.4g/kg = 2g/lb bodyweight
Conclusion
This is the first investigation in resistance-trained individuals which demonstrates that a hypercaloric high protein diet does not contribute to a fat mass gain. Furthermore, there was no change in body weight or lean body mass.
They did add this caveat towards the end; It would be intriguing to ascertain if a high protein diet concurrent with a heavy resistance bodybuilding training regimen would affect body composition (i.e. increase lean body mass and lower fat mass).
So it may just be that they heavier you train and the more hours you put into it may increase the need for amino acids. The train of thought is most recreational type weight lifters may need at max 1g/lb. Those that are training 1.5 hours a day 5-6 days a week, some anabolic steroid use may even need 1.5g/d/lb. Once you get into the competitive phase those needs may go up even further as training times may increase to 2 x/d with increases in cardio and a heavy array of anabolic steroids, IGF-1, HGH and insulin.
So it may be in fact be intriguing to see if proteins needs increase with highly trained bodybuilders in competition for a show. One thing most pros will tell you about protein intake is the importance of the extra calories and the increase in the thermic effect of food. That combined with high doses of anabolic steroids and HGH may mean further looses in body fat levels and the ability to actually grow or keep mass in the cutting phase.
Interestingly enough I did a 3 day diet recall on Mr. Olympia Phil Heath a few years back. Here are the general results:
Phil Heath
BW - - 280 lbs
He consumes 33cal/lb/bw
Daily protein = 3.25g/lb/bw
Daily total consumption: 9394 calories, 910g protein, 881g carbs, 239g fat
Protein = 910g = 3640 cal (39%)
Carbs = 881g = 3524 cal (38%)
Fat - 239g = 211 cal (23%)
Is this uncommon, absolutely not. Check out some of the strong man diets, Olympic swimmer diets or even some of the pro-football players diets.
Now does this mean we all need to consumer 1g/lb of protein? Absolutely not. most can get away with much less.