Generative AI needs a human in the loop to check its work. How many times does this need asserting?
Generative AI Is not an authoritative source.
In this case the app should have been framed as a tool to "help the user create a meal plan through generative prompts".
They could even have made fun of it in the guidance to the user. Point out that if you give it crazy ingredients it will give you crazy meals.
Generative AI is like having a smart intern do work for you, it needs checking. Sometimes they come to work having been out all night, still drunk, and powered by energy drinks...