Wednesday, February 25, 2009

Glycemix Index - What is it and how does it work.....


We keep hearing about this so i thought i would check it out. I found this info. on bodybuilding.com website under articles.

How It Works
The glycemic index refers to the relative degree to which blood sugar increases after the consumption of food. A food is always measured relative to the effect of pure sugar. High glycemic index foods can raise blood glucose levels very quickly, as well as insulin levels. In contrast, low glycemic index foods do not significantly raise blood glucose levels and insulin levels after eating. Pure glucose is given a value of 100 while other foods are given an index number representing its relative effect on blood glucose levels.

For example, sweet corn is assigned an index number of 55 which means sweet corn raises blood glucose levels 55 percent as much as pure glucose. In general, foods below 55 are considered low glycemic index foods, 55-70 represents mid-glycemic index foods and over 70 are considered high glycemic foods. In the past, it was widely believed that simple sugars dramatically increased blood glucose levels while starches such as potatoes and bread were digested slowly. The results from numerous studies show this is definitely not the case. In fact, one of the biggest surprises comes from potatoes, which reported an average index of 84, making it one of the higher glycemic foods available. Here's a look at how a high, mid and low glycemic value food can alter one's blood glucose response.
For Weight Loss
Most clients who come to trainers for help primarily want to lose weight or shed body fat. Can the application of the glycemic index to our food choices really help us lose body fat? Research has confirmed that one of the most effective ways to lose body fat is by eating 5 to 6 meals daily combined with resistance training and some form of cardio.

Small, frequent meals increase the thermic effect of food as well as prevent the body from going into starvation mode. Research further agrees there should be a larger portion of carbohydrates mixed with more moderate amounts of protein and fat. The glycemic index allows us to more effectively evaluate our nutrition plan focusing on the quality of carbohydrates. For those who incorporate a larger amount of low glycemic foods, they will be rewarded with a slow and steady release of glucose keeping insulin levels in check.

This is of tremendous benefit to those who complain of low energy when cutting back on calories. Since all nutrients are not created equal, low glycemic foods have the added effect of keeping individuals feeling more satisfied for longer periods of time. In contrast, high glycemic foods used early in the day could cause unwanted surges in glucose levels, leaving one feeling energy deprived as well as creating hunger pangs. Lower insulin levels play a critical role in how and when we store fat. These reduced levels make fat easier to burn and more difficult to store.
For Sports Performance
Athletes have long known that eating properly before training and competition can improve performance in measurable ways. Increased carbohydrate intake prior to exercise can be measured through increased muscle and liver glycogen stores as well as aid in the maintenance of blood glucose levels for sustained energy. Glucose levels then provide fuel for the brain, which allow us the luxury of good judgment and enhanced concentration levels while exercising. How, then, can the glycemic index help athletes in their performance?

Despite what may sound logical in applying the glycemic index, researchers have found that what you eat prior to endurance exercise does not necessarily play a role in your ability to sustain an endurance activity. Whether your meal consists of low, mid or high value foods does not seem to matter as much as what you consume to sustain your energy stores during exercise. While high glycemic foods do not play a favorable role in weight loss, they can have an important effect in sports performance.

Following a heavy training session, when muscle glycogen stores are depleted, high glycemic foods can provide a quick release of glucose re-filling energy stores. Within the first few hours following exercise, blood flow to muscles is increased. Glycogen synthesis can be optimized during this critical time by the use of high glycemic carbohydrates. One of the concerns expressed by athletes and coaches over the course of time is that ingestion of carbohydrates in the hour before exercise could cause a dramatic increase in insulin levels, ultimately causing hypoglycemia within a short time after exercise begins.
Recent studies have shown that even though high glycemic foods were taken prior to endurance exercise, the resulting performance was not affected. This is an important finding in that the quality of carbohydrates is less important in meals prior to exercise while potentially being of great significance to aid recovery in the time following exercise. There is still much debate on this subject.

Glycemic Index by Glycemic Load
(First Number in Parentheses is GL, Second is GI)

Low GI & Low GL
All-bran cereal (8,42)
Apples (6,38)
Carrots (3,47)
Chana dal (3,8)
Chick peas (8,28)
Grapes (8,46)
Green peas (3, 48)
Kidney beans (7,28)
Nopal (0,7)
Oranges (5,42)
Peaches (5,42)
Peanuts (1,14)
Pears (4,38)
Pinto beans (10,39)
Red lentils (5,26)
Strawberries (1,40)
Sweet corn (9,54)

Low GL & Medium GI:
Beets (5,64)
Cantaloupe (4,65)
Pineapple (7,59)
Sucrose (table sugar) (7,68

Low GL & High GI:
Popcorn (8,72)
Watermelon (4,72)
Whole wheat flour bread (9,71)
White wheat flour bread (10,70)

Medium GL & Low GI
Apple juice (11,40)
Bananas (12,52)
Buckwheat (16,54)
Fettucine (18,40)
Navy beans (12,38)
Orange juice (12,50)
Parboiled rice (17,47)
Pearled barley (11,25)
Sourdough wheat bread (15,54)

Medium GL & Medium GI:
Life cereal (16,66)
New potatoes (12,57)
Sweet potatoes (17,61)
Wild rice (18,57)

Medium GL & High GI
Cheerios (15,74)
Shredded wheat (15,75)

High GL & Low GI
Linguine (23,52)
Macaroni (23,47)
Spaghetti (20,42)

High GL & Medium GI
Couscous (23,65)
White rice (23,64)

High GL & High GI
Baked Russet potatoes (26,85)
Cornflakes (21,81)

2 comments:

Unknown said...

what a fabulous site!
i'm trying to get fit, and your site is so comprehensive and fabulous.

http://the-scarlettletters.blogspot.com

Martha Crowther said...

Thanks so much!