Insulin response is varied in individuals....but polyols certainly won't spike blood sugar because they are slowly and incompletely absorbed from the small intestine into the blood. Because of incomplete absorption - overeating the stuff can cause the runs.
I think they have something like half to three-fourths as many calories as sugar...but a calorie is a calorie. And calorie for calorie there are better things you could be eating. IMO you should use consume sugar alchohols sparingly if at all.
i've often made the mistake of eating too many carbolite bars, only to be stricken 30-45 minutes later with intense stomach cramps which last for the rest of the day usually.
So then sugar alcohols will definately kick you out of ketosis right? The new Odyssey bar tastes damn good but has something like 23g of sugar alcohols. Oh well........