Being tricked into eating a carrot is not a gross violation of human rights, but playful mischief among friends
. It's a matter of scope and intention I guess, and I agree it might not be the most considerate thing to do, but where would that kind of interpretation on consideration towards others leave other pranks, off-color jokes, etc? Everything is a violation of some right, no matter how slight, and everything is an offence to somebody, somewhere. If you want to have a laugh, at some point you must draw the line. Granted, the line might move back or forward depending on the person.
In my personal experience, when people found out about the trick, they were usually surprised--not offended--had a laugh, and some even eventually ended up opening up to the "taboo" ingredient. I understand not everyone is up for that though, so one must pick his/her audience carefully.
Choosing the audience is 90% of most good performances
It's also where a lot of non-professional jokesters fall flat: not grasping the difference between an audience who have paid to see Jimmy Carr versus your sainted grandma and her tea-and-scone friends.
I think also we're talking at cross-purposes, since the original question wasn't in the context of friendship, but an overall question about whether or not it's ok to feed people things they've expressed no intention of eating, which runs the gamut of friends to guests to total strangers at your hot dog stand.
I do seem to know a bunch of people who are deathly allergic to the weirdest stuff, though. I had lunch at a pub with a friend whose allergy is, as it happens, carrots, so she made it very clear to the waitress when she ordered that she couldn't have the carrots could she please have this dish with the carrots removed (side of carrots, not cooked into the main meal) due to her allergy and the waitress made it equally clear that she understood.
The meal arrived with carrots, delivered by the same waitress who had seemed to grasp the nature of the problem, only to forget about it ten minutes later. No real problem, my friend pointed out said deathly carrot allergy, and this is where the issue arose: The waitress was extremely apologetic, and offered to go scrape the carrots off the plate.
Except the carrots had already touched other items on the plate, and my friend really is that
Again, no problem. They kindly apologised and re-prepared the entire meal from scratch, this time without carrots. It cost us an extra 10-15 minutes, but on the plus side said friend is still alive. But she goes through some variation of this at least 50% of the time she eats out because nobody really believes that anyone can have a fatal carrot allergy (for bonus points, her husband is equally allergic... but to mushrooms).
So in the instance of, say, my mum stuffing onions into a meal when I've brought a friend to dinner who has said they can't or won't eat onions (one of the earlier examples) we're looking at a gross violation of human rights, and perhaps even illness or death caused by someone's belief that they have more right over what someone puts in their mouth than they do.
In the instance of you chucking some carrots into your best mate's mouth when you know 100% that while he hates carrots they aren't going to kill him? That's regular Britishness, that is
I mean, over here, c**t is a term of endearment between best friends.
There's a great Jimmy Carr joke from the end of one of his gigs I was at. It is horrifically offensive (but hella funny). He deconstructed it, explained exactly why it worked at that moment in the show
and would have fallen flat earlier on or - for example - in front of your mum over Sunday roast. The humour of it was, in part, due to the idea that someone might think it appropriate to whip that joke out in public in front of a cold audience.