I'm not low-carbing but I still think the sugar alcohols
should be avoided and apparently for good reason.
Should You Count Those "Net Carbs" or "Low Impact" Carbs
Every drugstore, supermarket, and department store in U.S. is filled
with snack products that claim to be perfect for low carb diet. The
labels on these products may list 24 grams of carbs but assure you that you
only have to count 2 or 3 of these grams in your daily carb allotment.
They may call these carbs "low impact carbs" or "net carbs" and display
them promenently on the front of the product, but the carb count on the
nutritional label--the only one that the FDA regulates will list a far
higher carb count.
If these disappearing "net carbs" make you suspicious, you may prefer
to buy products that list only a gram or two of carbs in their
nutritional information. But a look at their ingredient list may show that
mysterious substances like glycerine or polydextrose are major ingredients
of these bars, too--exact same substances reported on labels of bars
that claim "3 grams of Net Carbs" on the front of the package and list
20-something grams of carbs in their nutritional information panel.
What's Going on Here?
Most of these "low carb" products are sweetened with substances called
"sugar alcohols." Maltitol, lacitol, and sorbitol are some of names of
these sweeteners. Despite the name, these aren't sugars or alcohols.
They are hydrogenated starch molecules which are a byproduct of grain
processing. These sugar alcohols are manufactured by the three large
agribusiness companies: SPI Polyols, Roquette America, Inc. and Archer
Daniels Midland. Having saturated world with high fructose corn syrup, these
giant corn-producing companies have now turned to hydrogenated corn
starch molecules as yet another way to wring profits out of surplus corn.
Despite wrapper claims, these sugar alcohols are metabolized. Each gram
of a sugar alcohol turns into anywhere from less than 1 to as much as 3
calories. Erythritol comes in lowest, delivering less than one calorie
per gram. Maltitol--the sugar alcohol found in most "low carb" foods is
the highest, delivering 3 calories per gram. That is only a bit less
than 4 calories you find in regular sugar and starch.
It is because these sugar alcohols can be metabolized as carbohydrates
that US law requires that they be reported as carbohydrates on
nutritional labels and why their calories are included in calorie counts. But
though many food companies still mdo not report them in their label
Several years ago, after the FDA fined Atkins Nutritionals for ignoring
the 20+ grams of glycerin found in their product in the nutritional
panel of their Advantage Bars, the company invented the "Net Carbs"
designation that it now places on the front of wrappers--but not on the
nutritional panel. This ruse was so successful, they went on to licensed use
of this phrase and Atkins "A" to other companies so that they too could
continue deluding customers about the carb content of their foods. .
Small print on back of these label explains that fiber and sugar
alcohols have a "negligible effect on blood sugar". This, they suggest means
that you can ignore them, and magically converts foods that have 24
grams of carbs--and the associated calories--into foods with a
diet-friendly 3 grams.
If it were true that these foods did not raise blood sugar, it would
make them ideal for the low carb diet. However, it is not always true.
Some lucky people can eat these low carb treats and still lose weight on
a low carb diet. But hundreds of people who have stopped by the
alt.support.diet.low-carb news group to ask why their weight loss has stopped
cold, discover that it is these sugar alcohol-laden low carb junk foods
that have caused their long-term stalls.
The reason for this, is quite simply, that sugar alcohols, particularly
Maltitol, the one that is most common in these products, can have a
very significant impact on blood sugar. This isn't speculation. It's a
fact. Many people with diabetes, who track any rise in their blood sugar
with a blood sugar meter, find that these products cause a significant
rise in their blood sugar, contrary to the label claims.
I'm one of them. My blood sugar rises almost as high when I eat a
maltitol-sweetened Russell Stover "No Sugar" candy as it does if I eat a
regular Russell Stover candy of same size. The only difference is that it
takes two hours for the blood sugar rise to occur when I eat the "no
sugar" candy compared to the one hour that it takes when I eat regular
candy. This blood sugar rise is followed by a period of low blood
sugar--the hallmark of an insulin response--and, for me, the trigger for
intense, diet-busting hunger. So much for "truth in labeling."
I am not only person who has found this to be true. Fran McCullough
warns readers of the very high blood sugar spikes reported by diabetics
after eating glycerine-containing Atkins bars in her book, Living Low
A comprehensive review published by Canadian Journal of Diabetes gives
a very good overview of the scientific research into how sugar alcohols
affect both normal people and people with diabetes.
Note the finding, on Page 5, that for normal people, research shows
that chocolate bars sweetened with maltitol raised the blood sugar of
normal people as high as did chocolate bars sweetened with sucrose--table
Not for Everyone!
However, there are other people with diabetes who report that they
don't see a blood sugar rise when they eat foods containing these sugar
alcohols. They find these products give them a way to incorporate
legitimate treats into their diets and are grateful that they are now so
There are also a number of successful low carbers who report in diet
newsgroup that they have been able to lose significant amounts of weight
while including these "low carb" treats in their food plans on a daily
basis. You will often find them railing against "puritanism" of those
who warn new dieters against them.
So, clearly these products do not affect everyone in same way. For some
people they are a godsend. For others, they turn out to be "Stall in a
Why Do Sugar Alcohols Only Affect Some People?
Since it seems that only a subset of the population metabolizes sugar
alcohols as sugar, it is quite possible that some people lack some
enzyme(s) needed to digest them and turn them into blood sugar. Since those
people's bodies can't turn these sugar alcohols into glucose, they do
not experience a blood sugar rise when they eat them.
Lending some support to this idea is fact that some of the people who
report that they did not experience a blood sugar rise when they ate a
product with a sugar alcohol in it, add that they experienced intense
diarrhea or gas later on. These are classic symptoms of what happens when
starches pass undigested into lower gut where they may be fermented by
bacteria (causing gas) or suck water out of cells lining the colon
Many of us who do get blood sugar rise do not experience this diarrhea.
Our digestive enzymes appear to be able to break down these
hydrogenated starches into glucose--though given the time lag, this happens
Diabetes expert Rick Mendosa has a very interesting web page
http://www.mendosa.com/netcarbs.htm that points out "If the sugar
alcohols had no impact on our blood glucose, they would have a glycemic
index of zero. With the the December 2003 publication of Geoffrey Livesey's
amazing review of sugar alcohols, we now know a lot more about them
than ever before. His article, "Health potential of polyols as sugar
replacers, with emphasis on low glycemic properties," is in Nutrition
Research Reviews 2003;16:163-91.
Mendosa goes on to say: "Only two of the sugar alcohols have a GI of
zero, according to Livesey's research. These are mannitol and erythritol.
Several others have a very low GI, but two maltitol syrups have a GI
greater than 50. This is a higher GI value than that of spaghetti, orange
juice, or carrots."
What about Glycerine?
Glycerine is another sweet additive that manufacturers add to low carb
bars. Here again, you'll find tha, because manufacturers claim
glycerine does not raise blood sugar they omit it in the carb section of the
label information or, if they do list it, they do not include it in
number of diet-counted "impact" carbs. ( Glycerine is sometimes spelled
Glycerin and is another name for glycerol.)
As Lee Rodgers, proprietor of The Low Carb Retreat explains that it is
only true that Glycerine does not raise blood sugar when people are not
low carbing. Rogers states:
When liver glycogen is full, glycerol is converted to fat.
When liver glycogen is empty, glycerol is converted to glucose.
And sometimes just goes right through without doing anything
In short, if you are in ketosis (having emptied your liver of glycogen,
its stored carbs) glycerine is likely to turn into blood sugar, and
then, of course, it raises insulin, defeating mechanism by which low carb
weight loss takes place.
This past issue of Rick Mendosa's Diabetes Update Discusses in more
detail why FDA insists that glycerine must be treated as a carbohydrate on
What about Fiber?
Perhaps the most confusing part of new "net carbs" designation is that
it combines sugar alcohols and fiber in the same designation. This is
Fiber, unlike sugar alcohols, is not metabolized into a significant
amount of calories and does not turn into blood sugar. Therefore it can
usually be deducted from a food's total carb count.
But even here, a little caution is required. That's because labeling
laws outside United States often treat fiber differently. In many
European countries, fiber is already deducted from the label's total carb
count. For example, imported Scandinavian bran crackers that list 3 grams
of carbohydrate and 3 grams of fiber do not contain zero grams of
carbohydrate. If they followed U.S. labeling conventions, their labels would
show 6 grams of carbohydrate and 3 grams of fiber, since the European
labels have already deducted the fiber from the total. This is also true
of many imported chocolates.
To make it even more confusing, many U.S. nut labels also deduct fiber
from total counts, too--walnuts in particular. Despite fact that Walnut
labels usually say "3 grams total carbohydrate, 3 grams fiber" walnuts
are not a zero carb treat! They contain about 2 grams of carbohydrate
Net Carbs and Restaurant Food
Where "net carb" designation becomes truly dangerous is in restaurants
because new "low carb" restaurant menus do not giveyou complete
nutritional data or any hint of an item's ingredients, only the "net carb"
So for all you know, that "3 gram net carbs" cheese cake may contain 40
grams of maltitol, which is the equivalent of 30 grams of sugar. Nor
can you distinguish between a food that contains 10 grams of fiber and
one that contains 10 grams of a lacitol, the sugar alcohol many dieters
have found causes profound diarrhea. All you know when you see that "net
carbs" designation is that the carb count of the food you are about to
eat is much higher than what restaurant would have to report were it
giving you legal carb counts. You can hope that the additional carbs are
fiber, but you may very well be wrong.
So What Does This Mean for You?
If you are just starting out low carbing, you would be well advised to
treat with caution any supposedly "low carb" product that cites net
carbs rather than total carbs. If you are one of people who do metabolize
sugar alcohols, these "low impact carbs" will turn into regular, old,
high-impact glucose, and eating a couple of these treats each day can
easily derail your low carb diet by adding another 20 to 40 grams of
carbohydrate to your intake.
That's why you might be wise to try low carbing without any of these
suspect foods for the first few weeks of your diet until you have become
accustomed to how your body feels when your blood sugar has stabilized
on a truly low carb regimen. If you crave a sweet treat during these
first few weeks, try one of truly low carb treats and snacks whose
recipes have been posted on web. You can find these recipes using Google
Groups Advanced Search scanning the alt.support.diet.low-carb newsgroup for
term "REC." You'll find hundreds of recipes containing no "hidden
carbs" at all. Do this until you've gotten the hang of what low carbing
feels like to your body.
Once you've gotten into a steady low carb regimen and are losing weight
steadily, you can test these commercial "low carb" products to see what
effect they have on you. If you keep losing weight after introducing
them, you can relax. You are one of lucky ones who can, in fact, treat
them as having "low impact" carbs. If you don't, well, for you there's no
free lunch. Continue making your own truly low carb treats--and losing
If you are diabetic, you don't have to guess about how sugar alcohols
affect you. You can turn to your trusty blood sugar meter to see what
they do to your blood sugar. But if you test, test products containing
sugar alcohols 2 and 3 hours after eating. Testing only at one hour after
eating may be too early and you may miss blood sugar spikes they cause.
With the new "low carb" pastas, you may have to test as many as 5 hours
after eating and you should also look at your fasting blood sugar the
next morning. Several people have reported that while they didn't spike
on the low carb pastas, their fasting blood sugars were significantly
elevated the next morning.
Watch Out for Increased Hunger
No matter what you see on your scale or observe on a blood sugar meter,
be alert for an increase in your hunger level when you eat these "net
carbs" foods. My own experience and that of some other low carb dieters
who have reported this on the newsgroup is that some of "low carb"
products made with sugar alcohols cause an increase in hunger that is out
of proportion to the blood sugar readings they produce. I have found
this especially noticeable with foods containing lacitol.
If you notice yourself suddenly getting hungry, or just plain eating
more food after you have introduced a new "low carb" treat into your
diet, back off for a few days and see what happens to your hunger level. If
it goes down, you'll need to treat these foods with caution. The whole
point of low carbing is to eliminate the hunger cravings that make
dieting so difficult.
Don't Forget the Extra Calories
Even if you can eat snack products containing sugar alcohols without
experiencing blood sugar spikes or hunger cravings, it's worth giving
some thought to the question of how good an idea it is to fill your diet
up with calorie-dense low carb junk food.
Though the best selling diet book authors make it sound as if low
carbing somehow magically "melts fat away" this is not true. Low carbing
evens out blood sugar which eliminates hunger and makes it very easy to
eat a lot less. But to achieve long term weight loss you must eat less
than you burn each day.
As you get closer to your weight goal, this becomes more and more
evident. The smaller you are, the less food your body burns. As a result,
most people find they cannot get last the 20 pounds off without watching
their calories closely and eating only 9 - 10 times their body weight
in calories. (i.e. if you weigh 140 lbs you may find you have to eat as
little as 1269 to 1400 calories a day to lose, depending on speed of
your metabolism and your activity level.)
With that in mind, you can see why, independent of the blood sugar
issue, that snack bar with its 240 calories that you eat every day between
meals may have serious repercussions for your diet--it is adding 1680
calories a week--over 1/2 pound's worth of calories--besides replacing
more nutritious foods like the high fiber, low carb vegetables that are
an important part of the diet of long-term successful low carb dieters.