The IItemUseFinish function can be added to an item and will be triggered only when a user finishes using the item (e.g. finishes eating).

Importing the package

Link to importing-the-package

It might be required for you to import the package if you encounter any issues, so better be safe than sorry and add the import.
import mods.contenttweaker.IItemUseFinish;

The IItemRightClickFunction is a function with the following parameters:

The function needs to return an IItemStack.

zsItem.onItemUseFinish = function(stack, world, player) {
    stack.damage(1, player);
    return stack;