14year old son passed out several times er tests said he is most likely hypoglycemic. what are the not diabetic causes and other symptoms of those?

Poor appetite: Does your son eat three good meals every day. If not he may need to work on improving his food intake. Many people do not eat enough high quality protein, vegetables/fruits to maintain an adequate blood sugar level. He could possibly have an insulin producing tumor that would lower his blood sugar. Work on his diet. If this does not help, then he should see a doctor.