My daughter did that with apples. Applesauce, applejacks, Apples, Apple butter. Turned out she was allergic to apples. Dr. said that the thing they crave, many times is something they may be allergic to. I started her on Shaklee vitamins, watched labels (she couldn't have beet sugar either.) The vitamins started building the immune system, because Allergies are a sign of a weak immune system.
I am telling you this strictly from personal experience. When I changed the diet and removed the allergens, her appetite increased and she had less tummy aches and ear infections.
Look at all the things that contain corn, corn syrup,.....wait till you start reading the labels, you will be shocked.
If you have anymore questions, or want to contact me, please do.