When a Carb's Not a Carb: The Net Carb Debate
Will counting net carbs help or hurt weight loss efforts?
The Skinny on Sugar Alcohols
But researchers say the impact of sugar alcohols on blood sugar
levels and the body is not fully understood, and they may also cause problems
in some people.
"There are some sugar alcohols that can raise your blood
sugar," says Karmally. "Certain sugar alcohols do have a higher
glycemic index, and they still are not counted as carbohydrates by these
"When you tell a person 'net carbs' or 'impact carbs,' it's
very confusing," says Karmally. "A person with diabetes may think,
'It's fine for me to have as much as I want.'"
People with diabetes are advised to closely monitor their
intake of carbohydrates because their bodies can't produce enough insulin to
keep blood sugar levels within a safe range.
"I think we should not misguide people and make them aware
that these sugar alcohols also contribute calories," says Karmally.
"Too much of them can actually have a bad effect, and some of them can also
have a laxative effect."
Although sugar alcohols have been used in small amounts in
items like chewing gums for years, researchers say little is known about the
long-term effects of consuming large amounts of these substances.
Registered dietitian Jackie Berning, PhD, says she steers her
patients against products containing sugar alcohols for those reasons.
"I just don't know how they're going to react. We've never
put that much in," says Berning, an associate professor of nutrition at the
University of Colorado at Colorado Springs. "Some are going to get
diarrhea, and some are going to have gastrointestinal problems."
Calories vs. Carbohydrates
Berning says the larger issue she has with products that tout a
low "net carb" count is that they also often contain a lot of
"It's my guess that most people are restricting
carbohydrates because they want to lose weight," Berning tells WebMD.
"The point I think they're missing is that you may have 2
net carbs in this bar but you've also got 260 calories," she says referring
to double chocolate Powerbar. "I don't care that it's only 2 net carbs. The
thing is, have you done enough exercise, have you balanced the rest of your
diet to put in 260 calories in that bar -- whether it has 30 grams of
carbohydrates or 2?"
Rather than focus on what she calls "the little c" of
carbohydrates, Berning says people interested in weight loss should focus on
the "big C"-- calories.
Karmally agrees and says terms like net carbs shouldn't trick
dieters into thinking, "This is a free lunch, and I can have as much as I
want," just because a food company says the impact or net carbs are only so
"You lose track of the fact that foods have calories, and
what has impact on weight management is the number of calories you consume and
the amount of exercise you do," says Karmally.