All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
The basic ruling concerning foods is that they are lawful, as prescribed by Sharee'ah. It is not mandatory to check the lawfulness of the food by reading its ingredients, by asking, or anything else. However, this does not apply to meat because it is well known that most animals slaughtered by the People of the Book (Christians and Jews) in Europe and America are stunned by bolt shots or electric shock before slaughter. We have underlined in a previous Fatawa that it is unlawful for Muslims to eat the meat of these animals, although the basic ruling is that it is permissible for Muslims to eat the animals slaughtered by the People of the Book.
If you are asking about the foods that you believe most likely contain meat, then you have to ensure that the animal was slaughtered according to the guidelines of the Sharee‘ah.
Allah knows best.