I've had acorn bread. It's a Native American thing. I worked briefly on a reservation. You have to mix the acorns with a little bit of dirt (lol) to take away the acidity.
LOL I tried just about everything as a child. We ate crabapples routinely, just to prove we could. Bleck! I also ate some pokeberries once. Don't do this, they are poisonous. I thought they were elderberries, which you CAN eat, and look similar.
Hickory nuts are better than acorns but still not as good as black walnuts.
If you have to eat bark, you want the soft underbark. . .the crunchy outside stuff is hard to chew and won't provide you with much sustenance anyway.
--Nature Child
edited to add: I found a recipe for acorns! See the link: