I heard a talk by a woman who had worked extensively in Africa. I just can't remember which talk or which woman, but possibly Karin Cadwell. She had asked the women of the culture she was working with if they found they had experiences similar to ours (Americans) of extreme hunger or thirst during a breastfeeding. They said no, they didn't have that, but they did have a tremendous hunger just before a feeding was due, which they interpreted as a hunger for their babies.
Sincerely, Chanita
(Karin, if you are reading this, and I am misquoting you, or wrongly attributing this to you, I apologize)