I never believed that sugar truely affected behavior until I saw it in my niece. I don't think sugar effects most kids that way, but with her, it does make her very aggressive and hyper. I think of it like an allergy. Her parents have pointed out her aggressive behavior to her and explained that it's from sugar so she totally gets it that her sugar has to be limited. They buy "sugar free" products like popsicles and syrup for her, and allow her to have sugar at special occasions like birthday parties, but they prepare themselves for the wild animal she will become-- no impluse control at all.
As for time out, try having a basket of stuff in the time out spot that he can fiddle with, like a squishy ball to squeeze (take it away if he throws it-- explain it's for squishing only) and other small toys he can manipulate while sitting. Kids who are aggressive/hyper and get put in time out to sit still --well, it just isn't effective! Think of time out as a place to compose himself, not a place to "be in trouble" so it's OK to have something to hold until mom says it's time to get up