Coconut isn't high carb, IMHO. It is mostly fiber.

Nuts, coconut meat, dried (desiccated), not sweetened 100 gram: 24 carbs (16 fiber) -- 8 net.

I'm not sure how many oz of coconut that a cup and a half would be, it's not dense when it is shredded.

Coconut flour is pretty useful for low carb baking.