Bob W.
When I was in my early 20s I was stricken with an extremely severe neurological disorder that destroyed my career as a cosmologist (a professional astronomer who studies the general nature and origin of the universe). My condition deteriorated very badly, but in 1984 I underwent a special test for food allergies.
I now eat approximately 20 unprocessed foods (leading to a gluten and grain-free diet) as my entire diet and I drink distilled water as my only fluid; I would estimate that my health is now approximately 100 times better, and that, at 65 years of age, my hearing is better than when I was a teenager! My night vision is better, my problem with obesity is gone, and many other symptoms have either disappeared or vastly improved.