the debate over this issue is a fierce one....
Next Nutrition (makers of the Designer bars) claim that the effect of glycerin on blood sugar is so low that glycerin doesn't even have a GI rating.....but ofcourse they are out to sell bars....they have quite an elaborate ad in the new Muscle and Fitness that claims they will no longer hide the fact that their bars contain glycerin.....
....they are now promoting glycerine as a revolutionary "new" carb that doesn't make you fat.....I'd take these claims with a grain of salt.....the whole thing still seems shady....
regardless of this....sugar alcohol is not simple SUGAR....in fact they put this stuff into diabetic candies and things of that nature, precisely because it is not absorbed by the body the same way traditional carbohydrates are - yet they are still classified as a carb...and we know that they pack 4.32 cal/g.....
... I say the jury is still out on the entire matter.....