Low-carb
diets are here to stay. There is no question
that they can be very effective for fat loss
when done properly. But low-carb diets aren't
easy for those who are used to eating a lot
of carbohydrates. You must strictly limit the
amount of carbohydrates that you eat in order
to get results. It's not unusual for a low-carb
dieter to be found gazing longingly at a piece
of bread or cake!
But
here comes nutrition and supplement science
to the rescue in the form of non-impact carbs,
net carbs and effective carbs with the promise
of low-carb foods wrapped up in traditionally
high-carb packages! It sounds like a dream come
true to low-carb dieters who crave the taste
of carb-containing foods but still want the
results of a low-carb diet.
These
terms are the latest buzz words in the weight
loss industry but are people getting more than
they bargained for with foods and supplements
that are based on net, non-impact and effective
carbs? Could these designer-foods be slowing
or even stopping your progress on a low-carb
diet?
Let's
start with a little Nutrition 101. A carbohydrate
is a nutrient that is used by your body for
energy. It contains 4 kilocalories of energy
per gram (kilocalorie is the formal name for
calorie).
Your
body converts the carbs that you eat into glucose/blood
sugar for use in a wide variety of metabolic
processes. This conversion can happen rapidly
or slowly depending on the type of carbohydrate
food eaten. This rate is known as the Glycemic
Index. A higher number means the food is rapidly
converted into glucose - a lower number means
the food is more slowly converted into glucose.
For example, table sugar has a high glycemic
index while beans have a low glycemic index.
Generally
speaking, slower conversion of carbs into blood
sugar is better. Here's why...
The
faster food is converted into blood sugar, the
faster your blood sugar levels rise. When blood
sugar levels are high, your body secretes insulin,
its primary storage hormone. When insulin is
present in the bloodstream, energy nutrients
such as fat or carbohydrates are far more likely
to be stored rather than burned. In terms of
fat loss, this means fat is not readily mobilized
from fat cells and fat burning slows or even
stops.
By
controlling insulin secretion, you can effectively
improve your body's ability to mobilize fat
from fat cells. Once mobilized from the fat
cells, they are more readily burned for energy,
i.e. you lose fat. This is the basic premise
that most low-carb diets are based on (there
are exceptions, i.e. ketogenic diets, which
I will get into later in the article).
For
a more detailed look at the Glycemic Index,
check out:
http://www.glycemicindex.com/
Non-Impact Carbs:
Non-Impact
carbs, in a nutshell, are carbs that have very
little effect on blood sugar levels when they
are eaten. Since they don't have an impact on
blood sugar levels, they are technically "allowed"
on most low-carb diets.
Examples
of non-impact carbs that you'll see in low-carb
foods and supplements include fiber, sorbitol,
maltitol, and glycerol. Fiber is completely
indigestible by the body and passes through
unused. Sorbitol, maltitol and glycerol are
what are known as "sugar alcohols."
They are digested by the body but have little
to no effect on blood sugar levels.
Effective Carbs:
The
Effective Carb is the opposite of the Non-Impact
Carb. They are carbs that will have an effect
on blood sugar levels. In most low-carb diets,
the idea is to place a limit on Effective Carbs
to keep blood sugar and, therefore, insulin
levels under control. On a strict, low-carb
diet, this number can be as low as 20 grams
of effective carbs per day.
Effective
Carbs can be divided into two basic groups:
simple and complex carbs. Simple carbs are rapidly
converted into glucose by the body while complex
carbs (which, as the name implies, are more
complex in structure) generally take longer
to convert to glucose.
Net Carbs:
The
Net Carb count is basically the same as the
Effective Carb count. It's the total number
of carbs in the food minus the non-impact carbs.
These terms can really be used interchangeably,
which can be a source of confusion in consumers.
For
example, if a food contains 30 grams of carbs
and 10 of those carbs are fiber, the food contains
20 grams of net carbs. It's basically what's
left over after you subtract everything else.
The
term "Net Carb" was coined by supplement
makers after glycerol (the non-impact sugar
alcohol discussed above) was reclassified by
the FDA as a carbohydrate. Previously, it had
not been classified as either a carb or a fat
and supplement makers were able to use it as
a sweetener without adding to the carbohydrate
count of a protein bar. When this reclassification
took place, the carb counts of low-carb protein
bars increased dramatically! The term "Net
Carb" is a result of manufacturers wishing
to keep their carb counts down while still using
glycerol in the manufacturing process.
The "Up" Side:
1.
Non-impact carbs are very effective at reducing
the insulin response you get from eating foods
made with them. This means insulin levels will
stay more even throughout the day, which will
definitely improve the body's ability to burn
fat.
2.
Non-impact carbs help low-carb dieters stick
to their diets. There is no denying that sometimes
you just want to eat a cookie. By eating a low-carb
cookie, you get the enjoyment of the cookie
while still keeping your insulin levels under
control.
3.
Low-carbs foods are actually being used by people
who aren't on strict low-carb diets but who
just want to lower their carb intake. Non-impact
carbs are very effective for this purpose.
The Downside:
1.
While non-impact carbs don't affect blood sugar
levels, they still contain calories (except
fiber, which is not digestible). A person who
eats a lot of non-impact, carb-containing foods
is still getting all the calories of an equivalent
amount of regular carbohydrates! This fact is
never highlighted in advertising for non-impact
carb foods. Total caloric intake still matters
on low-carb diets. If your body is getting too
many calories, it won't need to burn bodyfat.
2.
If you eat large amounts (or in some people,
even small amounts) of sugar alcohols, you could
experience what could tactfully be called the
"green apple quicksteps," i.e. diarrhea.
Sugar alchols are not normally found in large
quantities in natural foods and the body can
have a hard time digesting them. What the body
has trouble digesting, it tends to get rid of
as quickly as possible (if you're familiar with
the results of eating Olestra, the fake fat,
you will understand what I'm talking about).
3.
If you're on a low-carb diet that is designed
to put the body into ketosis (a state where
the body burns ketones for energy instead of
blood glucose), you may find eating non-impact
carbs puts the body out of ketosis by providing
carbohydrate-like calories. In this case, the
non-impact carb basically defeats the whole
purpose of the low-carb diet. If you're on a
ketogenic diet, stay away from from foods that
have non-impact carbs as they will have an impact
on your diet.
4.
The FDA has not formally defined the terms "Low-Carb,"
"Non-Impact Carbs" and "Net Carbs"
as it has done with terms relating to fat content
in food. That will surely come, but in the meantime
many foods that are not particularly low-carb
can get away with labeling themselves low-carb.
As always, reading the nutritional information
on the package and noting serving sizes is your
best protection.
Is the recent flood of low-carb foods to the
marketplace here to stay? Big food manufacturers
are banking on it as evidenced by a recent Low-Carb
Summit in Denver attended by many major companies
such as Con-Agra and WalMart.
In
my opinion, however, the burning question when
it comes to low-carb foods is: are we getting
away from the real point of the low-carb diet?
Processed foods are what got us into the obesity
epidemic that we're in today.
Is
substituting one type of processed and manufactured
food for another type of processed and manufactured
food (albeit a "healthier" one) the
way to go or would we be better off focusing
on foods that are less processed and naturally
low-carb?
The
answer lies in how you choose to approach your
low-carb dieting. Foods that contain "non-impact
carbs" can certainly be useful on an occasional
basis but I don't believe it's wise to rely
on them for a significant portion of your food
intake. If you rely too much non-impact carb
foods, you could easily find yourself not losing
or even gaining weight on your diet!
