Epidemiological studies often define high protein intake as approximately 1.2 grams per kilogram of body weight and low protein intake as below 8% of calories, with these definitions encompassing a narrow range of actual intake.

“if you look at all of the epidemiology which I think is pretty bad science the definition of high protein is about 1.2 gram per kg and low protein is actually below 8 and so a lot of them will express it as percentage of calories and they'll say less than 10%”