The three diabetics I’ve cared for were all best controlled with a combination of diet and Levemir. Fancy Feast pate-style and no dry food; no need for “special” (read “way overpriced” food).
Check with Diabetic Cats in Need about the best ways to source Levemir or Lantus. I used to live in the Detroit area and just drove to Canada for it where it is over-the-counter and less expensive…
My wife and I have a Moluccan cockatoo and an Indian ringneck.
Think of parrots as very demanding, often destructive, toddlers that never grow up and have no “inside voice.” They will make you thank whatever god you follow that you can get subtitles on your television.