The proper balance is based upon your own life. If you are very active, you run or bike a lot for example, you need a higher balance of carbs. If you're more stationary a diet higher protein diet is better suited to your need. I guess it's all relative.
So many variables exist I don't think there is a "proper" way to diet. Everyone is different. But you need to make sure, no matter what, your body is receiving, through nutritious forms, daily requirements. The daily requirement can be found on the FDA site, or if not in the states, through a daily nutrition requirements site.
I'm not sure if we'll ever know the answer to this question and those similar. Honestly, the latest health news is always changing and contradicting itself. I say, eat a bit of everything and you should be fine.