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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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