A very interesting piece in this weekend's New York Times Magazine from science writer Gary Taubes about the evils of of sugar. A long piece like this is really impossible to excerpt, so you should just go read it... but the general idea is that if you consume enough sugar (including, but not limited to high fructose corn syrup - refined sugar is essentially identical), especially in liquid form, that when it is metabolized by the liver it is quite likely to be converted into fat... leading to insulin resistance and ultimately much worse things like metabolic syndrome and diabetes. It's an interesting theory, though I'm not personally familiar with any of the research being cited, so I can't attest to its validity... but the article is an interesting read nonetheless... and a great example of how to write about science. Unfortunately at the end... assuming you buy his story... the conclusion is: no, we don't know how much sugar is "too much".
So... I guess, being that I can consume it in quantities that would make an ten year old sick, I should probably cut back on the candy, huh?