To be Polite you need to eat at least something there, if not some of what is being served it's truly what you should do - If you were invited

G'day Free Spirit, Thank you for your question. You probably should eat a bit and say that you don't feel hungry. Then you get yourself a meal at a late night diner or raid the fridge when you get home. Regards

i`d just lie & say i`m allergic to it.

You politely excuse yourself from the table and the evening by developing a sinus headache that hurts so bad that it's making you nauseous. It's even better to ask what's for dinner a day or two prior to the event, so you can choose to cancel to avoid any discomfort.

Odds are I'd be allergic to it anyway.

I find that most people who say that they just can't eat something actually mean that they aren't willing to eat what it is. The polite thing to do would be to eat a small portion of whatever it is, even if you don't like it. If it is a situation where you will physically become sick and vomit, then you may be able to semi-truthfully say that you are allergic to it. After all, eating it would cause an adverse reaction.

If it is meat you can say you have a phobia of meat, because you have an irrational fear of meat. Stress the issue that it is all meat, otherwise the host will think that you have a problem eating food that isn't prepared yourself. Become a Vegan (only works for meat, again) Say that you are a very picky eater and that you can't help it, and that it is nothing against your food, but that you will hardly eat anything. Search for bread or salad on the table; I practically live on bread because I am in truth a very picky eater. I love bread and have been jokingly called a carb-aholic! I won't disagree! Say that you have a very sensative gag-reflex, and you can only handle foods that have bland textures. Say that you are on a ridiculously strict diet. Say that you are fasting. Say that you are feeling a bit light headed and that eating food at the momemt is probably not the best idea. You're not really hungry any way. Just tell yourself that, over and over, and the pain will subside eventually. Hope this helped, I am always saying at restaraunts, "I will just have frites," or "I will just have bread," Or "I will just have plain white rice," for chinese places. Man I love white rice with nothing on it but salt! mmmmmmm

I would lie to them and say I don't feel well all of a sudden and excuse myself to a rest room and act like I threw up. I would not want the person to feel bad since they did put hard work in making a meal, plus I'd get to practice my acting skills.