When I feed it. I cut the skin and about 1/4 " more and throw away the center portion or use it for human salad.
The center portion is so full of moisture that it always makes for messy poop.(diarrhea)
I only use it if Lola is constipated then I grate some onto his leaves.
He loves it, and when he smells it he comes running to find it - but I don't think there is a lot of nutritional value in it.