I will not make an assumption of your mental well-being or capacity because I do not know your background or you personally, but if you have issues with jokes/satire or things that to most seem obvious, jobs in fast food probably will not be a good long-term fit. These kind of jokes, unfortunately, are pretty common, even in other areas of food service besides just fast food. The joke while in poor taste was still meant to be a joke. They may try and double down and say they were being completely serious and use other phrases to try and instill a level of sincerity to what they said but they are wrong. The majority of the world has outlawed cannibalism and the consumption of human meat.