In other words, [link|http://www.mendosa.com/gilists.htm|how rapidly] usable sugar (i.e. glucose) shows up in the blood. Or, see an [link|http://www.glycemicindex.com/|Aussie site].

One of the interesting things is that even what are pure carbohydrates, e.g. fructose, and ordinary sugar (sucrose), are not terrible because it takes the body time to slice and dice these molecucles to form glucose. And cellulose we can't digest at all and passes through us (with minor use by some bacteria).