It's individual really and you have to set your own goal. I find bg at one hour after starting my meal is a good guide to how many carbs I can have. So basically, do you test? If not, do.
Then many people report it's easier to control carb intake if you keep it low or you'll start craving carbs.
To fill up properly many find fat is the most filling option and doesn't have much of an impact on bg either nor is it bad for the kidneys.
So my advice, for what it's worth, is to keep a protein level you and your kidneys are happy with and reduce carb and up your fat intake while testing bg frequently in the beginning. You'll find your sweet spot eventually but it really is trial and error.
I rarely have more than 25 grams of carbs in a day so have a lot of fat instead as I work physically hard and need the energy. This suits me.