What is the Glycemic Index?

[motof]

I have heard tons about the glycemic index but have never really put much thought into it or using it when forming my diets. could someone please brief me on what it is and the benefits of "low glycemic index foods"

thanks!
Motof

[motof]

well i have been doing some reading and have found the absolute basic of glycemic indexes: the glycemic index measures how fast a food will increase my blood sugar levels.

A high GI will increase my BSL much quicker, such as the case with donuts, syrup, and potatoes

Some low GI foods are foods which are high in fiber like whole grain rye bread.

[Packup Pete]

What is the Glycemic Index?

The glycemic index is a new system for classifying carbohydrate-containing foods, according to how fast they raise blood-glucose levels inside the body. In simple terms, a food with a higher glycemic value raises blood glucose faster and is less beneficial to blood-sugar control than a food which scores lower.


The Glycemic Index Scale

The glycemic index consists of a scale from 1 to 100, indicating the rate at which 50 grams of carbohydrate in a particular food is absorbed into the bloodstream as blood-sugar. Glucose itself is used as the main reference point and is rated 100.


What is Glycemic Load?

Glycemic Load is the application of the glycemic index to a standard serving of food. Remember, the glycemic index (GI) of a food is not based on commonly consumed portion-sizes of foods. Instead, GI is measured by giving volunteers a portion size sufficient to contain 50g of useable carbs. Therefore the portion size of each GI-tested food will vary according to how much carbohydrate it contains. For example, carrots contain only about 7 percent carbs, so the test-portion of carrots eaten by the test-volunteer will be huge - about 1.5 pounds. Serving sizes of foods (like bread) which contain a higher percentage of carbs, will be smaller.


High Glycemic Index Foods (GI 70+)
that cause a rapid rise in blood-glucose levels.

Intermediate Glycemic Index Foods (GI 55-69)
causing a medium rise in blood-glucose.

Low Glycemic Index Foods (GI 54 or less)
causing a slower rise in blood-sugar.



Glycemic Index of CerealsKellogg's All Bran 51
Kellogg's Bran Buds 45
Kellogg's Cornflakes 84
Kellogg's Rice Krispies 82
Kellogg's Special K 54
Oatmeal 49
Shredded Wheat 67
Quaker Puffed Wheat 67

Glycemic Index of Grains
Buckwheat 54
Bulgur 48
Basmati Rice 58
Brown Rice 55
Long grain White Rice 56
Short grain White Rice 72
Uncle Ben's Converted 44
Noodles (instant) 46
Taco Shells 68

Glycemic Index of FruitApple 38
Banana 55
Cantaloupe 65
Cherries 22
Grapefruit 25
Grapes 46
Kiwi 52
Mango 55
Orange 44
Papaya 58
Pear 38
Pineapple 66
Plum 39
Watermelon 103

Glycemic Index of
Vegetables
Beets 69
Broccoli 10
Cabbage 10
Carrots 49
Corn 55
Green Peas 48
Lettuce 10
Mushrooms 10
Onions 10
Parsnips 97
Potato (baked) 93
Potato (mashed, instant) 86
Potato (new) 62
Potato (french fries) 75
Red Peppers 10
Pumpkin 75
Sweet Potato 54

Glycemic Index of Beans
Baked Beans 48
Broad Beans 79
Cannellini Beans 31
Garbanzo Beans (Chickpeas) 33
Lentils 30
Lima Beans 32
Navy Beans 38
Pinto Beans 39
Red Kidney Beans 27
Soy Beans 18
White Beans 31


Glycemic Index of Pasta
Spaghetti 43
Ravioli (meat) 39
Fettuccini (egg) 32
Spiral Pasta 43
Capellini 45
Linguine 46
Macaroni 47
Rice vermicelli 58

Glycemic Index of Breads
inc. Muffins & Cakes
Bagel 72
Blueberry Muffin 59
Croissant 67
Donut 76
Pita Bread 57
Pumpernickel Bread 51
Rye Bread 76
Sour Dough Bread 52
Sponge Cake 46
Stone Ground Whole wheat bread 53
Waffles 76
White Bread 70
Whole Wheat Bread 69

Glycemic Index of Dairy
Milk (whole) 22
Milk (skimmed) 32
Milk (chocolate flavored) 34
Ice Cream (whole) 61
Ice cream (low-fat) 50
Yogurt (low-fat) 33

Glycemic Index of Snacks
Cashews 22
Chocolate Bar 49
Corn Chips 72
Jelly Beans 80
Peanuts 14
Popcorn 55
Potato Chips 55
Pretzels 83
Snickers Bar 41
Walnuts 15

Glycemic Index of Cookies
Graham Crackers 74
Kavli Crispbread 71
Melba Toast 70
Oatmeal Cookies 55
Rice Cakes 82
Rice Crackers 91
Ryvita Crispbread 69
Soda Crackers 74
Shortbread Cookies 64
Stoned Wheat Thins 67
Vanilla Wafers
Water crackers 78

Glycemic Index of Sugars
Fructose 23
Glucose 100
Honey 58
Lactose 46
Maltose 105
Sucrose 65


How Blood Glucose Works

In simple terms, for the sake of our health, blood-glucose levels need to remain within certain levels. The body regulates these blood sugar levels using two mechanisms: hunger and insulin.
-- When blood-glucose levels fall, the brain causes us to feel hungry. Result? We eat food that is converted into glucose and our blood sugar levels rise. If we don't eat and blood-glucose levels fall too low, we trigger the condition known as hypoglycemia.
-- When our blood-glucose levels rise, the brain tells our pancreas to release insulin. Result? The insulin helps to disperse the glucose and our blood sugar levels fall. Without insulin to regulate a rise in blood-glucose, the amount of sugar in our bloodstream can become toxic, triggering the condition known as hyperglycemia.


Effect of Carbohydrate Foods on Blood Glucose Levels

When carbs are eaten and digested, they are converted to glucose and enter the bloodstream where they raise blood-glucose levels. How fast these carbs raise blood-sugar levels depends on their glycemic index value.
-- Individual carb-containing foods or (more commonly) carb-containing meals with a high glycemic index value cause a "spike" in blood-glucose levels. Meaning, our blood-sugar rises very fast, triggering an equally rapid response from the pancreatic gland which pumps out enough insulin to deal with the excess blood sugar. Result? Within an hour or so, the large secretion of insulin has dispersed all the excess blood glucose and then some. So we feel hungry again!!
-- Individual carb-containing foods or carb-containing meals with a low glycemic index value raise blood-glucose levels in a slower more sustained manner. So the pancreas responds by releasing a more moderate amount of insulin. Result? Hunger is kept at bay and we feel satisfied for longer



What Are Carbohydrates?

Carbs are the main energy source for the human body. As the name "carbohydrate" suggests, carbs are a mixture of carbon, hydrogen and oxygen. Carbohydrates are manufactured inside plants from carbon dioxide in the air and water, under the influence of sunlight. (A process called photosynthesis).


Types of Carbohydrates
Carbohydrates are classified in various ways.

-- Carbs can be classified into types according to their molecular or biological structure. The two main types are Simple Carbohydrates (or "simple sugars"), like Monosaccharides and Disaccharides; and Complex Carbohydrates (or "complex sugars"), like Oligosaccharides and Polysaccharides.

-- Carbs are sometimes classified into sugars, starches and dietary fiber (aka. non-starch polysaccharides). Generally, sugars are "simple carbs", while starches and dietary fiber are "complex carbs". But fructose (fruit sugar) is a simple carb that behaves like a complex carb!

-- Carbs can be divided according to how fast they are digested, and thus how quickly they raise our blood sugar levels. The Glycemic Index divides carbohydrate-containing foods into high, medium or low glycemic index foods.

-- Carbs can be classified into refined or unrefined carbohydrates, depending on how "processed" they are by food manufacturers


Glucose Metabolism

Glucose is the body's fuel. Without glucose, or without being able to convert it into energy rapidly and efficiently, we cannot survive in good health. So it's very important that our energy-metabolism system works efficiently. Here is a very simple explanation of how we convert glucose into energy.
-- In response to the rise in blood-glucose levels (say) after a meal, the pancreas releases insulin which "mops up" the glucose and carries it to cells that need extra energy.
-- The glucose enters the cell by special molecules in the membrane called “glucose transporters”.
-- The cells that need glucose have specific insulin receptors on their surface so that insulin can bind to them, encouraging glucose entry and utilization in the cells.
-- Once inside your cells, the glucose is burned to produce heat and adenosine triphosyphate, (ATP) a molecule that stores and releases energy as required by the cell.
-- The metabolism of glucose into energy may occur either in combination with oxygen (aerobic metabolism) or without it (anaerobic metabolism). The oxygen used comes from the mitochondria - tiny bodies inside the cell. However, red blood cells do not have mitochondria, so they change glucose into energy without the use of oxygen.
-- Glucose is also converted to energy in muscle cells - who are probably the most important energy "customers". These muscle cells do contain mitochondria so they can process glucose with oxygen. But even if oxygen-levels in the muscle-cell mitochondria fall too low, the cells can proceed to convert glucose into energy without oxygen. Unfortunately, turning glucose into energy without oxygen produces the by-product lactic acid. And too much lactic acid makes your muscles ache.


Glucose Storage

Our food-intake and energy-needs do not always coincide. For example, we may have lots of food, but no energy needs. Or we may need lots of energy but no food in sight! Fortunately, glucose can be stored as glycogen (an "energy reserve") for later use. Without such a glucose storage system, we would either have to eat constantly or risk a dangerous lack of energy.