We noted a decrease in muscle protein mass only with aging. (academic.oup.com)
In this post you will find out what every bodybuilder should know about this hormone that tends to reduce the total protein mass. (bodybuilding-wizard.com)
«the lowest level of dietary protein intake that will balance the losses of nitrogen from the body, and thus maintain the body protein mass, in persons at energy balance with modest levels of physical activity.» (diagnosisdiet.com)