Question for people who have worked in fast food kitchen?

I guess you could call it kitchens lol anyway i love fast food it bad for you but what American doesn't

For people who have worked in McDonald's Burger King Taco Bell Pizza Hut long John silvers Hardee's or Carl's jr you get what I mean lol

I've heard over and over again McDonald's Burger King etc doesn't use real meat in there burgers chicken or real potatoes in there fries.

Is this really the case all give you example someone told me the micrib that McDonald does around the Christmas isn't real meat is this true for anyone who made it
Burger King I've heard the onion rings there are not with real onion is thus true

Etc is this true about all fast food places allot of there food isn't made with real meats or onions or etc is this true and why and how do they get away with it.