As I was saying to ElyDave further up on this thread, increasing calories from fat and decreasing protein has been the secret of my success on this run of low carbing. More fat really helps with reducing hunger. You just don't feel hungry. I don't think protein has quite the same value. And for a Type 1 diabetic on a low carb diet, protein complicates things because it can be turned into glucose. But the ratio that protein turns into carbs is hard to predict, can be quite changeable. And even if you dose properly with insulin for the protein (if needed), the extra insulin is liable to take you out of ketosis. So all told, fat is easier and better as a source of calories in your low carb diet than fat.
A commonly quoted target is 80% calories from fat, 15% from protein, 5% from carbs. But this is very strict. You can get a good low carb diet going with much less strict percentages than that.