Inventory Management?

I don't know if I'm just missing this feature on the site/app. Looking for guidance, or if this doesn't exist, I'll put in a request.

Pretty much every meal results in some form of leftover. Is there some way to annotate that in meals (when planning out a week), such that the shopping list doesn't produce duplicate items for meals that have already been made? Even to use empty space in the Shopping List to tell me which recipe the item is for would enable me to remove unneeded items.

Does this exist? Am I missing something?

Thanks!!