> and if so how?
I use ketosis strips (Ketostix). You pee on them, and they tell you. Totally worth the 5$ they cost.
I'm happy in full ketosis, or no ketosis at all, but the "half-way" ketosis state is just pure torture.
The strips let me know how good I'm doing, so if things deviate a bit, e.g. because one day I ate ""too many carbs"", I notice quickly, and auto-correct.