It would be nice to have a book that pulls in all food items (perhaps check if the item is edible, or has hunger/saturation value, however) and presents a list of those items, along with a mark if the food's been eaten or not. I know that the text "Not yet eaten! What does it taste like?" gets added, but trying to search for this with "#yet" (JEI's flag for tooltip search, for the word 'yet') doesn't return results. If such a book had an option to filter between foods eaten, foods not eaten, all foods, this would be even better.

It gets quite tedious after a few hundred different foods to manually search through JEI for foods one has not yet eaten to make more progress in getting more hearts.

This will be part of the next update! Implemented in 04dc6de

Awesome news! Thanks! :)

The new update just got approved on CurseForge!

Feel free to reopen this issue if you feel it's not yet adequately resolved :)