Wait, they started taking ingredients? (I understand cheese, since it is considered a dish.) I haven't seen that. I thought the whole point is they wouldn't eat things that are typically used for other things. Fruit is also for planting, for example.
But they officially take milk, now? Mine have always gone for the cheese/leftovers. (I don't care if they eat leftovers, personally, so long as the neighbors aren't raiding my cooking ingredients as happened to you.)
Oh, nearly forgot, all for a fridge lock, though. Especially a detailed one that prevents specific things. I always want them to be able to get leftovers, but I'd love to be able to forbid specific types of food/cooking/quick meals. While we're at it, let me lock the other kitchen appliances. (You don't need coffee when you can just sleep! You're just going to let it spoil anyway, Sim 2175.)