1) You shouldn't have told anyone about it except for (perhaps) people you trust. I know I've learned my lesson, I just don't want to *bother* explaining this to anyone (during the fast itself), ESPECIALLY if it's a nurse or anyone in the medical field. They think they have all the answers, seriously.
2) Now that they know, lie your *** off. Be a hermit for a little while and call people on the phone instead of getting together. Have non-food related get togethers. Say you've already gone out to eat or at worst tell them you ate something.
3) Let them know and if they don't back off, just avoid them for your fast. Ask themselves to educate themselves on it if they want to speak to you about it.