We do the Halloween Fairy where the kids leave some of their candy and get a small toy or healthier treat in return (we did pirate booty, the kids clif bars, coupons for movie/popcorn night, etc., cheap easy stuff). Well, she had to make a return trip a day later because dd FREAKED out after eating a red lollipop and I just couldn't deal-so all of the candy minus 4 pieces of chocolate (so no artificial colors, etc.) and dd actually happily traded the rest of her candy. I did give her some "natural" lollipops in return because she loves lollipops. I was really surprised she did it so willingly, but I think she really "got" why she was feeling so yucky and crazy after I explained it to her!
I did leave the rest of dsd's candy for her-she is pretty good about self-regulating and chances are I will end up tossing 75% of it in a few weeks-she did take a bunch to her mom's house too though.
I tried letting dd pick some candy for hte day (maybe 5-6 pieces?) and she sat and ate it all in a row, leading to a major sugar meltdown later. Maybe she is just too little for self-regulating, maybe it just isn't her personality! I would hve eaten it all at once too, lol!