Goodness! I don't have anything at all to do with Lobsters (they aren't kosher), squid, locusts or slugs. It makes me wonder what the origin of kosher or halal (close but not precisely the same) dietary rules are. Many foods are prohibited, many of which most people don't eat anyway. As far as I know, however, there are no plant foods that are forbidden under anyone's rules, which is not to say that you can eat just any plant. Even so, we had rhubarb growing in the garden when I was little but I wasn't aware that it was food. Anyway, most if not all food prohibitions are religiously based. Some people, not many, eat monkey meat. There was also a belief in WWI that some imported canned meat in France was monkey meat. But that's just a curiosity in this discussion.
Part of the Islamic dietary laws involve how animals are slaughtered, so there is some concern over animal welfare. And the butcher can even be Christian or Jewish. The rules for that and kosher are fairly complicated and I don't wish to overly simplify things.
Some religious prohibitions about food have more to do with bodily submission than anything else, apparently, and self-denial, a totally foreign concept to most people. And likewise, some foods (or some things eaten as food) have more to do with just the opposite. Overall, however, I'd say that humans are highly adaptable food-wise, just like rats.