Don't Remove Past Meals From Meal Plan, Let The User Mark Them As Completed
After the meal time is passed, keep the meal visible in the meal planning section, and rather allow the users to mark it as "done" only when it's been cooked/eaten - then maybe just grey it out instead of removing from list, and let users undo if they did it by mistake.
I made a meal plan one evening, added recipes for 7 days, went to the supermarket and bought all the ingredients. The day after I opened the app, and realized that the recipe from the day before was gone. The app assumed that I already used it, so it was removed automatically.
Now I have 1 kg of mushrooms in my fridge and I don't really know what to do with them...