Insulin will spike with just eating, and in response to protein/amino acids.
I think it is not as much insulin released, but it is still released.
There are so many factors involved, like what your bodyfat is, as the lower it is, the more likely nutrients will go to muscle.
There is also your activity level, so if you are quite active or someone who never sits still, you will burn a lot of calories.
CC79, did you multiply your BMR by your activity level?
I really wish that low carb diets worked for me, I am trying one out again, but it does seem whenever I drop one of my macros too much, I just end up with uncontrollable urges for the macro I dropped.