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By
Nick Nilsson
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!
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