Some times it amazes me how we don't know the answer to this, I have always thought that for some reason, the powers that be don't want us to know. But now days i think when you look at it, who wants to spend money on studies? Either protein manufactures or sports coaches I maybe, but the medical industry in the main don't really care.
The biggest problem I see is that there are soooooo many variations, from person to person, peoples lives, peoples training, sleep, different types of protein, peoples goals, are they maintaining, bulking etc. we will never know the exact answer because there is no exact answer.
It would seem from the most recent studies from people with no real agenda other than trying to find the truth, our diets should be higher is protein than it shows on the current food pyramid that we are shown.
Also, after reading many written journals online, articles, and info online ,that the bigger guys, natural and not, have to eat a regular protein throughout the day. If you ready stuff from Natural bodybuilders especially, you see that some seem to be really in tune with their body's.
We can get far too caught up in ratio's and amounts of protein, Myself probably more than most, I read lots about the subject and I can not remember the last time I had 6 protein containing meals in a day, or have had a week of getting even 1.5g per KILO every day.
As long as you have no kidney issues and assuming you drink a decent amount of water then 20 to 30g of protein 5 to 7 times per day, should allow most men that train with weights to continuously gain strength and size. If you are particularly big or train for endurance as well, then you will probably need more.
I think that if you were doing a low carb, or higher volume training 50g 6 x per day like the palumbo diet wont do you any harm at all, will it help you grow faster thant 30g 6 x day? i don't know, just do what suits your life. Now, when i listen to my own advice ill be able to give you some real life experience opinion