How much Protein is needed for body building

Protein requirement for healthy adult is 0.8-1 gram per kilogram and 1-1.2 grams per kilogram for an elderly person. The American college of sports medicine recommends 1.2 to 2.0 gm of protein / Kg for athletes. During fat shredding  1.2 gms of protein per kg of ideal weight is good and for muscles building 1.8 gm per kg of ideal weight is recommended.