Glycemic Index of Carbohydrates
There has been much conversation over the years
about carbohydrates. As our population started to put on more and
more weight some people even suggested that carbs were the problems.
If people would eat fewer carbs it would result in weight loss. That isn't the case. Your
body must have carbohydrates to burn for energy.
Not too long ago it was assumed carbs could be
broken into two groups, simple and complex carbs. Complex are better
for you than simple based on how long it takes to digest them. Even though there is a degree of truth there,
the reasoning is based on incorrect assumptions.
And how specific carbs are categorized is not correct
based on the glycemic index.
About 20 years ago, a research scientist,
David J. A. Jenkins, M.D., Ph.D., D.Sc from the University of
Toronto, decided to test the complex carbohydrate theory. In 1981, he used
glucose, blood sugar, as the constant to compare other carbs to.
From this he developed the glycemic index. Simply he did clinical
tests where people
consumed different carbs and then he tested their blood to determine how
fast the carb was digested and hit the blood stream. The faster it
was in the blood, the higher the glycemic index of that particular
What are High Glycemic Index Carbs?
High-Glycemic Index foods are quickly digested and
absorbed, producing a rapid rise in blood sugar and resulting in high insulin levels. Low-GI foods, on the other hand, are slowly digested
and absorbed, producing a smaller, more gradual rise in blood sugar
and much lower insulin levels. Why is this important? High levels of blood
sugar and insulin have been linked to many of the health problems
that are so common today.
The GI of a food is influenced by a variety of
factors including the degree to which a food is processed; how long
the food is cooked; the kind of starch, sugar, or fiber the food
contains; and the foods acidity. In general, anything that speeds
the rate at which a food is digested and absorbed will raise its
Foods that rank high on the
glycemic index include products made from finely ground flours like
bread and baked goods; processed breakfast cereals; snack foods like
chips and pretzels; baked, mashed, and French fried potatoes; and
short-grain (sticky) rice. Foods that rank lower on the glycemic
index include most vegetables and fruits; sweet potatoes; legumes;
minimally processed whole grains such as thick-cut oatmeal, oat
bran, long-grain brown rice, barley, and bulgur wheat; pasta; and
The glycemic index tells you how
quickly a carbohydrate-containing food turns into sugar, but it
doesn’t tell you how much carbohydrate is in a serving of a food.
To assess the full impact of a food on blood sugar levels you should
have an idea of both. This is where glycemic load comes in.
|Adult Set Diabetes Type II is an epidemic
|Diabetes is the leading cause of new cases of
blindness among adults aged 20 to 74 years|
|7% of the total population in 2005 has
diabetes, almost half don't know it|
|Less than 1% of the age group 0-20 have
|9.6% of the age group 20-60 have it|
|20.9% of those over 60 have it|
|More men over age 20 get it than women; 10.5%
of men, 8.8% of all women|
|Sixth leading cause of death listed on U.S.
death certificates in 2002. Diabetes is likely to be
underreported as a cause of death since people with diabetes die
from other health issues caused by the diabetes. (Read Free
|The risk for death among people with diabetes
is about twice that of people without diabetes of similar age.|
|Heart disease and stroke account for about 65
percent of deaths in people with diabetes|
|Diabetes is the leading cause of kidney failure|
|73 percent of adults with diabetes have blood
|60 percent of non-traumatic lower-limb
amputations occur among people with diabetes|
|People with diabetes are more susceptible to
many other illnesses and, once they acquire these illnesses,
often have worse prognoses. For example, they are more likely to
die from pneumonia or influenza than people who do not have
|By the time a person is diagnosed with
diabetes, there is already cardiovascular damage.|
|Diabetes causes a large number of free radicals
which in turn cause massive damage to the body
Why am I mentioning diabetes here?
There is a direct relationship between consumption
of high glycemic foods and developing insulin resistance. Diabetes
is caused by insulin resistance.
It is important for all of us to understand the
glycemic index of foods we eat. You must eat carbs for energy but
eat the right ones. Read here about Diabetes,
a different perspective on preventing and curing it.
Who can Benefit from Eating
Low on the Glycemic Index?
By helping to maintain lower blood sugar and insulin levels, a
low-GI diet may be useful in preventing and treating a variety of
the health problems. Here are some examples of how eating low on the
glycemic index can help promote excellent health:
- Substituting low-GI carbohydrates (like thick-cut oats, pasta, and
legumes) for high-GI carbohydrates (like processed cereals, white
bread, and potatoes) can help lower blood glucose levels in people
with diabetes. This is why the GI has been an integral part of
medical nutrition therapy for diabetes in Australia, New Zealand,
Canada, and Europe for many years.
A low-GI diet may also help
prevent diabetes from ever developing in the first place.
Harvard University researchers who tracked the eating habits of over
100,000 men and women found that people whose diets are low in fiber
and high in refined and high-GI carbohydrates are more than twice as
likely to develop type 2 diabetes, as are people who eat a
fiber-rich diet with a low glycemic load.
Insulin is a cellular growth factor. Many studies have shown an
association between high insulin levels and a variety of cancers
including breast, colorectal, prostate, and pancreas. Other studies
have shown links between diets high in sugar, refined carbohydrates,
glycemic load, and cancer. This suggests that lifestyle changes like
maintaining a healthy body weight, exercising, and eating a healthy
low-GI diet may help protect against cancer at least partly by
lowering insulin levels.
disease - As with type 2
diabetes, researchers have found that a diet high in refined and
high-GI carbohydrates may substantially raise the risk for heart
disease. These foods increase blood insulin levels, which in turn
contribute to a higher blood pressure, higher levels of blood fats (triglycerides),
lower levels of HDL (good) cholesterol, and an increased tendency
for dangerous clots to form and linger in the blood.
- People who have meal-related
reactive hypoglycemia secrete too much insulin after eating. This
causes the cells to remove so much sugar from the blood that they
feel weak, shaky, irritable, headachy, unable to concentrate, and
very hungry with a few hours of eating. Choosing low-GI
carbohydrates can help prevent this type of hypoglycemia because
eating foods that promote a gradual rise in blood sugar and a lower
insulin response reduces the likelihood that blood sugar levels will
drop too low.
Since low-GI foods are slowly digested, they provide a gradual and
sustained rise in blood sugar. This keeps you feeling full and
satisfied and delays the return of hunger between meals. Conversely,
high-GI carbohydrates provide short bursts of energy that satisfy
you in the short term but soon leave you hungry. Many of the
fat-free and low-fat foods that have become popular over the last
decade—such as bagels, processed cereals, rice cakes, crackers,
snack chips, and cookies—tend to rank high on the glycemic index
and may actually contribute to a pattern of overeating in some
people. (see the section on Obesity and weight loss here for more
information on this process and why most people can't lose weight
without addressing insulin resistance.)
Ovary Syndrome (PCOS) - This
disorder affects about 7 percent of reproductive age women. Symptoms
include altered hormone levels, disturbances in the menstrual cycle,
infertility, and acne. Because PCOS is often associated with insulin
resistance, women with this disorder are at increased risk for
developing diabetes, high blood pressure, and heart disease.
Measures that improve insulin sensitivity, such as weight loss and
exercise can help reverse PCOS symptoms. A low-GI diet, which
minimizes insulin secretion, may also confer benefits.
Performance - Low glycemic index
carbohydrates should be chosen for pre-competition meals and snacks.
These slowly digested carbs provide a steady stream of glucose to
working muscles during exercise and enhance performance by making
glycogen stores last longer.
When high-GI foods are eaten just
prior to a "sports" competition they can actually impair performance because
they stimulate more insulin, which speeds removal of glucose from
the blood and can lead to hypoglycemia. On the other hand, high-GI
carbs are the preferred choice after the event because the insulin
surge helps replenish muscle glycogen stores.
(The above chart of people who can benefit from
low glycemic carbs it taken from Sandra Woodruff. Her book is an
excellent source of information and meals using low glycemic foods.(1)
Woodruff, MS, RD, LD/N is author of "The Good Carb Cookbook:
Secrets of Eating Low on the Glycemic Index"