The New Atkins & Sugar Alcohols
One of my big issues with TNA is the concept of subtracting sugar alcohols from Net Carbs.
IMO, the most fraudulent practice in the LC field is the total subtraction of SA's in the calculation of net carbs. There are 1.5-2.5 cal/g for most of them (except erythritol which is 0.2 cal/g) and these calories are from carbs!
Here's what TNA says on the subject:
"When it comes to low-carb foods, you subtract grams of sugar alcohols (including glycerin), as well as of fiber, from total grams of carbs to get the Net Carb count."
"Many low-carb products are sweetened with such ingredients as glycerin, mannitol, sorbitol, xylitol, erythritol, isomalt, lactitos and maltitol. ... Because sugar alcohols are not fully absorbed by the gut, they provide roughly half the calories that sugar does, although each one varies slightly. The incomplete and slower absorption results in a minimal impact on blood sugar and insulin response. This means that sugar alcohols don't significantly interfere with fat burning, making them acceptable on Atkins. ... Most people find that they can handle 20 to 30 grams a day without undesirable effects."
I imagine this was quite a point of contention between the powers that be at Atkins Nutritionals and these three respected researchers. There's much to be read between the lines of how it is written.
The veteran low-carber is probably aware that the "missing carbohydrate" on Atkins labels for some of their products is attributed to glycerin (aka glycerine, aka glycerol!). Apparently AtNu tried, unsuccesfully, to get glycerin classed as a fiber, when, in fact, it is clearly a sugar alcohol and WP&V make a point of identifying it as such. I may be reading too much into this, but I get the feeling this was a face-saver for these three. In exchange for going along with subtracting sugar alcohols, they got to inform the consumers of Atkins products and "out" glycerin is a sugar alcohol in hopes the LC community would pick up on this? That's just my feeling on the whole issue.
In any case, they acknowledge the caloric content of SA's but not the carb content. If slowed release of carbohydrate doesn't "interfere with fat burning", then what's the point of counting carbs at all so long as they are ingested in very small quantities? Glycerol is absorbed and metabolized ... and turned into ... drumroll please ... glucose!! These grams are not even accounted for on Atkins' labels (or they weren't last time I looked -- I don't eat these, ever). We're often talking about 20 or more grams of sugar alcohols in a serving of "product". Subtracting these completely can result in a 10g or more "error" in your carbs. That's significant, and if it's not, what's the whole hub bub about counting carbs anyway?
The authors seem obsessed with the carbs in lemon juice. So much so that Rung 7 for adding more includes 2T more lemon juice. I do best on LC lately when I drink cayenne lemonade all day long. If I have a cup of lemon juice per day (6g sugars, ~20g total carb) or 20g sugar alcohols, which do you think is going to impact weight loss in the right direction?? It's for this reason I harp on this seemingly minor aspect of the book. They can't have it both ways. One of the things they advocate to counter stalls is to go back to counting carbs -- Net Carbs of course. They don't address laying off the sugar alcohols for stalls. But too much protein, that's the staller!
In such a self-proclaimed "grounded in science" book, they fail to even mention the difference between erythritol and the other sugar alcohols. Again, perhaps because AtNu doesn't use it much in their products?
In the end, I would like to see a more forthright discussion of the carbohydrate content of sugar alcohols. If we can't expect that from these trusted scientists, who can we turn to?