The diet of Muslims is basically the same as that of Jews. The most important thing is that they don't eat pork and any food related to pigs. Moreover, if they eat cows, sheep, chickens and ducks, they must be slaughtered by professional Islamic butchers and recite the name of Allah before they can eat. Fish, cheese, cakes and vegetables can be eaten, but nothing made of animal fat can be eaten. Because non-halal animal fat is also illegal. It should be ok to confirm and inform him that he does not contain animal fat.

Non-halal food upstairs refers to food made by non-Muslims. I don't agree with this statement. Even vegetables are not halal. That's embarrassing yourself. . In that case, mineral water made by non-Muslims cannot be drunk. The only foods that God forbids are wine, pork, dead things, and animals that were slaughtered before God's name was pronounced. . As long as the food does not contain these, fish can be eaten without slaughter, as long as there is nothing prohibited in it.

These all need to be explained to Muslims. Whether Muslims eat or not is a personal matter.

I hope to make it clear and correct me.