In every case, it appears that as a country rises out of abject poverty, they can't wait to start buying packaged, processed food. I don't see this as detrimental to those folk's health though. Food prep becomes less of an all day chore, and more like a necessary task that has to be fitted in with a busy schedule.
Another factor to consider, is what percentage of a family's income is required for food. There is a huge difference there, between say, Mali and Canada.