T Nation

Net/Impact Carbs

Hey All,
Can someone explain to me the significance of “impact” carbs? I always see these low carb drinks or low carb protein bars that say they have 2-3 grams of “impact” carbs on the cover and then you look at the food label and they have like 15-18 g of carbs! Please explain!! Also, if one is counting total carbs for the day…would you use the “impact” or “net” carbs or the total carbs on the food label? Thanks…Tony G

Tony G,
I’m not sure if this is the whole picture, but I think that the “non-impact” carbs are fiber and other types of “carbs” that aren’t going to affect your insulin.


Look here, about halfway down under “A Question About Impact Carbs.”

the non-impact carbs they’re talking about are carbs from glycerin. supposedly they don’t have any impact on the glycemic index. in Testosterone print mag #8, there’s an article on protein that talks about it. not sure if it’s online.

Sugar alcohols like glycerine/glycerol, maltitol, sorbitol were formerly ommitted from carb counts on bars, but since they have a caloric value over 4 per gram, they were re-classified as non-impact carbs. They supposedly have a “negligible impact on blood sugar levels.” I’ve heard that they aren’t absorbed, but I’ve also heard the opposite. I read some studies that showed assimilation of these sweeteners, so I add them into my total calorie count if I’m cutting.

Thanks People,
I think I get the gist! Basically the sugar alcohols (glycerin, sorbitol, etc) do have calories but elicit a very low score on the II or have a negligible effect on insulin…correct? However, like the post said in the reader mail link given to me…we shouldn’t trust those labels that say “3-4 grams of impact carbs”…its all a bunch of hogwash…right?

Its a gimmick to get you to buy the product. “This bar has 100g of carbs, but we’ll tell your body not to process but 3!!” Read the t-mag link in the previous post.