We got tons of candy and my kids spent the morning counting, sorting, organizing and counting again. Good math activity right? :D Now that they have it all figured out (and my one over-the-top child made a chart for all of his candy in categories) they are calm and eating lunch. After lunch we will start school. I don't know why playing with it for three hours wears off the enthusiasm but it does.
Every day my kids are allowed to have a small un-healthful snack after they eat a healthful one. After Halloween they usually choose a piece of their Halloween candy (and after Christmas they choose Christmas candy, after Easter...). I still get the annoying questions the first couple of days but then they give up. Before I had my step-children I just let my kids eat the candy when ever they wanted, they self-regulate very well and always the day before Christmas I would throw away a huge bag of Halloween candy they never got to. My step-children though have FASD and don't self-regulate at all, so we had to set up a system.
My children don't react to sugar, they are just always full of endless energy lol