The doctor said to me, “You don't have cancer, but nothing else is working right.” That's when I was sent to the large allergy clinic and the problem was found. My small intestine had been rendered smooth by Celiac disease so it did not absorb nutrients.
I saw a woman on TV tout a diet that eliminates 7 food types for 2 weeks. Then reintroduce them into your diet one at a time. If you don’t get a bad reaction fine. If you do then keep it off your diet.