correct ratio of carbs to protein

[ravs2k6]

Okay, we've all heard the CORRECT ratio of carbs to protein is 3 or 4 to 1.
Does anyone know WHY it is better then say 5 or 6 to 1? Or even WHY is it better then 1 to 1?
Anyone have a study or know where I can find it on the www?

thanks.