One pound of muscle tissue contains ~100 gram of protein. Therefore, an individual would have to ingest an extra 14 grams of protein per day to gain 1 pound of lean mass weekly. Although this calculation is easy, in practice, it is not that simple. Most experts believe the single most important factor in gaining lean mass (along with resistance training) is consuming a hyperenergetic diet. To ensure the body has sufficient energy for lean mass creation, consume an additional 200-400 calories daily above maintenance requirements in addition to consuming a little extra protein.