This question has become quite the ''hot topic'' of conversation in the low carb community lately. I've asked a few people about it, but to get the real answer, I asked my friend, Dr. Michael Hellemn for his view on the subject.
"Pretty simple with the protein. Protein does not actually build muscle, exercise does. You can drink those muscle-builder protein shakes all day and never look like the person on the cover of the package. You still have to get to the gym. The protein goes into the blood, and is only taken out by the muscle that needs it. So, if a muscle gets stressed, it decides that it better expand. Then it looks into the blood for the building supplies. Bone is the same way. When bone is stressed, it adds more mineral to become stronger. Calcium will not make your bone stronger. Exercise will make the bone want to add calcium.
The blood is very much like one of those conveyor-belt sushi restaurants. I don't know if you have ever seen one. The restaurant has a conveyor belt on the counter. The customers sit at the counter and take off the sushi that they want. I may be in the mood for mackerel, so I may wait for a mackerel dish to go by on the conveyor belt.
My old gym had a poster with a photo of 2 guys. One was a chubby couch potato, and the other was a slim muscular athlete. The caption said "Both of these men are 6 foot and 200 pounds". The men have the same BMI, but their health is likely quite different."
I appreciate the explanation on protein Dr. Hellemn. Thank you for your insight on this subject !