"Not usually eaten" depends upon your region and culture. So I'll list items (that come to mind at this moment) that I now eat living in Hawaii but didn't eat when I lived in NJ.
Sweet potato leaves and growing tips.
Radish and daikon leaves and stems.
Beet leaves and leaf stems.
Pea tendrils and flowers.
Pipinola (aka chayote) growing tips and root.
Banana flower core.
Lemon and lime rind.
Plus I simmer parts for making stock but don't actually eat them (they get fished out afterward and fed to the livestock).....
Onion skins and discarded tops & root
Over mature bean pods
Stemmy parts of various herbs
Leaves of allspice and clove
Discarded tough parts of broccoli, cauliflower, cabbage, etc
Peelings from kohlrabi, parsnips, turnips, sweet potatoes, etc
Plus I've used fruit discards for making flavorings....
Pineapple rind and core
Lemon and lime rinds
It's never too late to start! I retired to homestead on the slopes of Mauna Loa, an active volcano. I relate snippets of my endeavor on my blog : www.kaufarmer.blogspot.com
this is a weird question, whaddaya mean "not usually eaten"?
not eaten by whom?
the burger binging concrete dweller?
I did not know, that you USUALLY DO NOT eat a lot of the things I always ate
why would I not eat the core of a pinapple?
or onion leaves? or leaves of caigua, chayote, beets, kohlrabi, carrots, radish, pumkin, nasturtium ...
or lot's of flowers? 1st bouquet of roses I got, I ate
why not eat Broccoli stems, it's still broccoli, right?
chards are grown for their stems
lemon + orange rind is sold candied, why not eat without the sugar?
pumkin, watermelon, ... seeds? dry, grind, use as flour
I got this tall by not having enough crisco in my diet as a kid. This ad looks like it had plenty of shortening: