Another thread recently made me realize I don't understand fructose metabolism as well as I should. For the purposes of this discussion, let's focus on pure fructose, though in practice most foods, e.g. fruits, that contain fructose, also contain glucose and sucrose (which breaks down to fructose and glucose). And the metabolism of fructose also appears to be affected by the presence of other sugars, so those probably need to be discussed, too.
If I'm not mistaken, fructose is not absorbed directly by cells in the way that glucose is, mediated by the presence of insulin. Instead, fructose is broken down in the liver into glycogen and lipids. The glycogen can replenish liver and muscle stocks, the lipids can increase insulin resistance, indirectly affecting blood glucose levels.
But this explanation must be incomplete, because fructose raises blood glucose levels nearly as much as glucose does (albeit a little more slowly). How does fructose do that? Or is that a function of the fact that fructose is usually accompanied by substantial amounts of glucose and fructose (in an apple or a grape, say). I'm pretty sure even pure fructose raises blood sugar almost as much as glucose does.
If fructose metabolism isn't mediated by insulin, pure fructose would seem to be an ideal diabetic sugar, with the caveat that it might contribute to insulin resistance, obesity, etc. But it doesn't appear so ideal in practice, why is that?
And if the above is correct, is fructose a poor way of meeting near-term BG needs, whether as a result of a low or because of ongoing athletic activity?
Clearly I'm somewhat confused. I noticed that neither Think Like a Pancreas nor Pumping Insulin have anything interesting to say about fructose, which seems odd. And Google yields stuff that's either too simplistic or too complex for me to digest (pun intended).