A person ought to eat the way they think they ought to eat, for their health, their faith, their budget, whatever. If you want to be an ovo-lacto-vegetarian, or a vegan, or keep kosher or halal, or a Paleo diet, or whatever, then that's what you ought to do.
But don't go waving it around in public, signalling how holy and righteous and healthy and woke and sensitive you are, and drawing attention to yourself everywhere you go. I've seen people make a huge deal in restaurants about what they will and will not or can and cannot eat, and act all surprised and hurt when the restaurant can't accommodate them.
That's just childish selfishness and narcissism, and annoys everyone around them.
I used to work with a guy named Maury, a consulting engineer, who was an orthodox Jew who kept strict kosher. When we'd go out to eat in the evening as a working group, he was just part of the gang, and you'd never even notice that he didn't really order anything to eat, just a few drinks and maybe some dessert after a quick quiet consultation with the waiter.
Or Maya, another engineer who was a Hindu and did not eat meat of any kind. She never mentioned it and never made a big deal of it, just ate what was available when we went out. I figured out what the deal was, and just let her order for both of us when we were out somewhere (as well as picking the restaurant!).
But save me from these guys who announce to the world "I DON'T EAT GLUTEN OF ANY KIND" and then look around proudly to see what kind of impression they've made ...
Well you did ask, well, opened the door anyhow ...