I had a japanese friend once who swore to me that it was entirely normal to eat the peals of several fruits within his family and their extended family in rural japan. I have never really interrogated how widespread the phenomenon is, but he regularly ate all kiwi skins, citrus skins, apple cores (no seeds), and more that I can't remember now (maybe watermelon rind? I think so). He really opened my eyes to that possibility, and I started eating several of them regularly. Citrus I never grew to find tasty enough to continue, but I still just eat whole apples and kiwis and shit. Actually pretty good once you're used to it