I am an airline pilot now (for just over a year, this is my second career…)
Since I was diagnosed diabetic 10 yrs ago, I had to jump through special hoops to get the FAA (federal aviation administration) to allow me to have a medical certificate under a “special Issuance” allowing me to fly. I had to supply medical documents annually to show that my disease was controlled and not devolving into renal failure, retinopathy or neuropathy - ie kidney eyes and feet.
Well, I went keto Halloween Oct 31, '17, and was able to get off all medications Jan 23, '18 with an A1c of 6.0. At my next checkup in early April, my A1c had dropped to 5.9, and my BP was 110/70
As required every year, I put in those medical status documents at my April FAA medical exam.
2 months later, I get a letter from the FAA saying that I was off my special issuance, was on regular medical standards, and despite my history of T2D & hypertension, I no longer needed to give them medical updates.
Someone at the FAA AMCD (aviation medical certification division) was willing to concede, in writing, that diabetes is reversible/curable.