It's always an advantage, when confronted with situations which could be socially uncomfortable, to be able to blame that social indescretion on a medical condition. For demonstration purposes, we'll use a fictional conversation.

Person #1: "Geeze guy, why don't you just pick up the plate and pour the food down your gullet?"

Person #2: "Excuse me?"

Person #1: "Oh great, not only do you eat like a hog, you're also hard of hearing."

Person #2: "I beg your pardon, I certainly am not 'hard of hearing. I simply didn't catch what you were muttering"

Person #1: "Fine, let me draw you a picture. You eat like a freakin' starved moose. You may as well dump your food in a cannon and blow it down your throat. That could help some poor bystander from having a severed limb, should they get in the way of your knife and folk."

Person #2: "I'm sorry if I've offended you, sir, but I have a medical condition known as tachyphagia."

Person #1: "Oh man, am I ever sorry. I apologize, I never knew there was such a condition. I really feel like a worthless, unsympathetic boor now that I know what's going on. Please, will you accept my apology?"

Person #2: "Think nothing of it, sir. Apology accepted."

Tachyphagia is the rapid eating of food.

Sources:

http://medical-dictionary.thefreedictionary.com/tachyphagia