The amount of protein you need is really dependant on how your body responds. Many people do just find and gain just fine with .5 a gram a day per pound of weight, natural or not. Personally, I have seen people stuff down protein shake after protein shake, chicken breast after chicken breast. Yea, they were happy because they started gaining weight, but they were fooling themselves because all I noticed was a bigger waist and more bodyfat. Protein powder manufactures keep spreading stories by so called experts that you ABSOULTELY have to have or you won't gain 1.5, 2, I have even now seen 3 grams of protein per pound of bodyweight.
I don't agree with a lot of what TA says, but I have to agree with him about the ultra high protein diets, some people may need it, but many do not.