Posted this in another thread too:
Excessive protein intake for a natural might actually “program” the body to turn protein into energy (gluconeogenesis) instead of muscle tissue. And the more efficient your body becomes at that process, the harder it will become to build muscle and even lose fat. A decently lean natural who consumes more than 1 gram of protein per pound of bodyweight when in a mass phase, or more than 1.2 grams when cutting, is doing himself a disservice.