Hm in my native language I would say "când corpul cere" and in english it says when my body asks. Maybe it sounds off through translation but I believe that our body is very wise. If I have a big crave all of a sudden for something and it does not go away I take it as a sign that maybe I have a deficit in my body and that food helps it. It can be apples, potatoes, meat or something else. I learned to listen to my body and not denying myself some foods. Of course this is different from constant cravings some people can have for fast food or alcohol, it is a total different story.