Why the Glycemic Index Works
By Frank Patino, M.D.
There are 3 different types of foods: FATS, PROTEINS & CARBOHYDRATES. Fats & Proteins have little effect on Insulin.
Carbohydrates on the other hand have differing effects on Insulin, i.e. “Not all carbohydrates are created equal.”
 The Glycemic Index is based on the carbohydrates Glucose. This is how the GI is
derived: 50 gms of Glucose is administered to an individual in a “fasting state”. The glucose is absorbed into the blood
quickly, causing a rapid rise in the curve.
In response to this high level of glucose in the blood, the pancreas secretes Insulin, which binds to Insulin Receptors on
cells. When Insulin binds to the receptors on cells, it opens special channels, which allows the Glucose in the blood to
enter the cell.
If the cell in diagram (B) is a muscle cell, then Glucose is used for muscle contraction. If the cell in diagram (B) is a
Liver cell, then Glucose is used for functions associated with Liver cells, such as detoxification. If the cell in diagram
(B) is a fat cell, then Glucose is converted to FAT.
We can now calculate the area under the curve for Glucose in diagram (A) and assign it an arbitrary number of 100. By doing
this, we can start an Index (GI) which uses Glucose as the base. We can now compare all Carbohydrates to Glucose.
We can repeat this for all Carbohydrates. E.g. Broccoli:
Here is how the Glycemic Index shapes up (for further information and glycemic counts, visit www.mendosa.com):
|
Glycemic Index
|
| Glucose |
100 |
Peach |
42 |
| Broccoli |
30 |
French bread |
95 |
| Cherries |
22 |
Red Baked Potato |
93 |
| Banana |
55 |
Rice Cakes |
82 |
| Apple |
38 |
Beer |
110 |
| Pear |
38 |
Instant Cooked Rice |
87 |
| French Fries |
75 |
|
The curve for Blood Glucose is important because of its effect on Insulin. Insulin raises step-for-step with Blood
Glucose.
Blood Glucose levels decline rapidly as Insulin binds to receptors on cells and allows the Glucose in the blood to enter the
cells via special channels. The low Blood Glucose levels turn off the stimules to the Pancreas to secrete Insulin. Since the
Insulin molecule is large, it declines at a very slow rate.
 If you look at diagram (h) you see that by mid morning you have Low Glucose Levels and
High Insulin Levels. This High Insulin Level is very important. When Insulin levels are high it binds with receptors on FAT
CELLS. When FAT CELL receptors are bound with Insulin, it prevents the breakdown of FAT to FREE FATTY ACIDS. Under normal
circumstances when blood sugar is low, you need an alternate fuel source. The alternate fuel source is derived from the
breakdown of FATS to FREE FATTY ACIDS.
When Insulin Levels are high, it binds to receptors on FAT CELLS and PREVENTS the breakdown of FAT to FREE FATTY
ACIDS.
Since you can’t break down FAT to FREE FATTY ACIDS, you now don’t have an alternate fuel source. Your Blood Sugar Levels are
low, so you get a “hunger pang” at mid morning and you then eat more High Glycemic foods, which again elevate your Blood
Glucose.
Your day unfolds with persistently High Insulin Levels, which prevent you from metabolizing the FAT stored in your FAT
CELLS.
Alternatively if you eat a Low Glycemic Diet your day unfolds differently.
By eating a Low Glycemic Diet, you prevent the Insulin spikes you noted in diagram (k). Therefore you do not bind Insulin to
receptors on FAT CELLS which allow you to utilize the breakdown of FAT to FREE FATTY ACIDS as an alternate fuel
source.
My recommendation is that you stay below 46 on the Glycemic Index in order to derive these benefits.
For more information, I would suggest reading Dr. Mendosa's website:
Glycemic Index: General Information
Glycemic Index: Advanced Lists
|
