What is the difference between I haven't eaten since morning and I haven't been eating since morning?

I haven't eaten since morning - he /she might not have eating resources. I haven't been eating since morning - He/she has resources, but doesn't will to eat.

They both have the same meaning, however "Been" adds emphasis on the time. "Morning"

I have not eaten since morning (Past action which is relevant to the present but emphasis the action)

I have not been eating since morning (Past action which is relevant to the present but emphasis the duration of the action)