Glycemic Index Table

What is the Glycemic Index?

The Glycemic index (GI) is a ranking of foods based on their potential to raise blood sugar levels.  The higher the GI of a food, the faster the resultant rise in blood sugar after eating it.  And the higher the GI, the higher the body’s insulin response tends to be.  Why is this important?  High levels of blood sugar and insulin in the body have been linked to many of the health problems that are so common today: diabetes, heart disease, obesity, to name a few.

The glycemic index has been the subject of scientific research for over twenty years.  It was originally developed as a dietary strategy to help people with diabetes gain better control over their blood sugar levels.  Today the GI is widely accepted in Canada, Australia, and much of Europe, and its use has expanded to include roles in treating obesity, cardiovascular disease, and various other health problems.  Health professionals in the United States have been slow to adopt this revolutionary way of classifying carbohydrates.  However, this is rapidly changing as mounting evidence on the benefits of the GI make this a topic that can no longer be ignored.  The health effects of high-versus low-GI foods are summarized below:

High-GI Foods

  • Are quickly digested, causing a rapid rise in blood sugar and insulin levels.
  • Provide short bursts of energy that may be quickly followed by hunger and a roller-coater pattern of overeating.
  • Promote excess insulin secretion, which may increase the risk for diabetes, cardiovascular disease, and some types of cancer and may contribute to a variety of other health problems.

Low-GI Foods

  • Are slowly digested, allowing for a gradual rise in blood sugar and insulin.
  • Provide a slow-release form of energy that sustains you between meals and promotes a healthy body weight.
  • Protect the body from the harmful effects of too much insulin.

Protect the body from the harmful effects of too much insulin.

Ranking foods on the Glycemic Index

Determining the GI of a food is a fairly complicated process so the GI of every food is not known.  However, researchers have tested a variety of common foods, some of which are shown here.  These tables list the glycemic indexes of foods when compared to pure glucose, which has a GI of 100.  When comparing foods, the following scale will help you put the GI in perspective:

  • Very low GI = 39 or lower
  • Low GI = 40 to 54
  • Moderate GI = 55 to 69
  • High GI = 70 or higher

Many foods that are often thought of as “health foods”—rice cakes and baked potatoes, for instance—have very high indexes, while “junk foods” like potato chips and chocolate have relatively low indexes.  Is there any rhyme or reason to the glycemic index?  Yes.  The GI of a food is influenced by a variety of factors, including the degree to which the food is processed; how long the food is cooked; the kind of starch, sugar, or fiber the food contains; and the food’s acidity.  In general, anything that speeds the rate at which a food is digested and absorbed will increase the GI of a food.  The section “Factors That Affect the Glycemic Index of a Food” over the page provides more details about what factors can raise or lower the GI of a food.

Of course, the glycemic index cannot be the only factor that determines which foods you should eat.  As you can see from looking at Table 1.1, just because a food has a low GI does not necessarily mean it is good for you.  It’s important to consider all the nutritional qualities of a food when planning your diet.  This guide will help you make the best choices based on this philosophy.

While the GI should not be the only criterion used for choosing foods, some generalities can be drawn from Table 1.1 that can help guide you in choosing foods:

Foods That Raise the Glycemic Index of Your Diet

  • Bread
  • Potatoes
  • Breakfast cereals
  • White rice
  • Pasta
  • Processed snack foods like chips, crackers, and pretzels

Foods That Lower the Glycemic Index of Your Diet

  • Vegetables
  • Fruits
  • Legumes
  • Minimally processed whole grains
  • Dairy products

Realize that some variations exist within these lists.  For instance, not all kinds of bread and potatoes have a high GI.  The section “Factors That Affect the Glycemic Index of a Food” provides more details that will help you make these distinctions and help you to plan varied and satisfying meals and snacks.

What effect do sweets have on the glycemic index of your diet?  Many candies, cakes, cookies, and sodas have moderate GI.  However, these foods are very concentrated sources of carbohydrate, and the workload they place on the pancreas is considerable.  Since sweets are often high in calories and low in nutritive value, they should be eaten with your total carbohydrate and nutrition goals in mind.

Perspective on Portions

How do portion sizes affect the glycemic index?  The more carbohydrate you eat in a meal, the more insulin your pancreas must secrete to process the carbohydrate.  For instance, eating a 4-ounce bagel will cause twice the insulin response as eating a 2-ounce bagel.  Choosing low-GI goods will minimize the amount of insulin that you secrete when you eat carbohydrates, but portions are still important.

Factors That Affect the Glycemic Index of a Food

Table 1.1, which lists the glycemic index of a variety of common foods, reinforces the statement that all carbohydrates are not created equal.  However, at first glance, the glycemic index may not seem to make much sense.  Why do two starchy foods like pasta and potatoes have such different indexes?  And why does fruit have a lower GI than bread?  Differences in cooking and processing methods; the chemical structure of the starches, sugars, and fibers in foods; and the presence of fat, protein, or acid can all markedly affect the GI of a food.  Knowing more about how these factors affect the digestibility of foods will help you make sense of the GI.

Milling, Grinding, and Processing of Grains

Modern food-processing techniques, such as grinding, pulverizing, puffing, extruding, and otherwise destroying the natural intact form of whole grains, make whole grains easier to digest and absorb.  This is why most breads, breakfast cereals, snack chips, and crackers have such a high glycemic index.  This is also why thinly cut instant oats have a higher GI than thicker cut old-fashioned oats.

Cooking

During cooking and baking, the starches in foods like grains, pasta, breads, and muffins absorb water.  This causes the starch granules to swell and rupture, a process known as gelatinization. Gelatinized starch is readily attacked by digestive enzymes and very quickly digested and absorbed.  Bread has a high GI partly because the starch in the finely ground flour used to make bread is easily gelatinized.  And soft, overcooked pasta has a higher GI than firm, al dente pasta because the overcooked pasta absorbed more water during cooking.

Many of the processing methods used to make extruded, flaked, or puffed cereals and snack foods involve steam-cooking at very high temperatures and pressures.  This fully gelatinizes the starch in these foods and contributes to their high glycemic indexes.

The Type of Starch Present

Starch is a storage form of glucose found in plant foods.  Because starch is composed of hundreds or thousands of glucose molecules that are strung together in chains, it is often referred to as complex carbohydrate. Scientists have long believed that because starch has a complex structure, it is more slowly digested than simple sugars.  However, the glycemic index has proven this notion to be false.

There are two main kinds of starch present in plant foods—amylose and amylopectin. When these starches are digested, their glucose molecules are liberated and absorbed, causing a rise in blood sugar.  However, because of the differences in their chemical structures, these two starches have very different effects on blood sugar.

Amylopectin’s structure resembles the branches of a tree and so it is easily attacked by digestive enzymes.  Starchy foods that contain a high proportion of amylopectin—like baking potatoes and sticky short-grain rice—are quickly digested and produce rapid rises in blood sugar levels.  Amylose, on the other hand, consists of a long, straight chain of tightly packed glucose molecules that resists digestion.  Foods high in amyylose—such as new potatoes and basmati rice—are absorbed more slowly and have lower glycemic indexes.

The Type of Sugar Present

Many people are surprised to learn that with the exception of glucose (GI = 100), most sugars have low to moderate glycemic indexes.  Fructose, the sugar that occurs naturally in fruits, is very slowly absorbed, giving it a GI of only 23.  Lactose, the sugar naturally present in milk and dairy products, has a GI of 46.  This is one reason why most fruits and dairy products have such low glycemic indexes.  Sucrose (white table sugar), a combination of equal parts fructose and glucose, has a GI of 65.  The fact that sucrose is part fructose is one reason why many sweets have a moderate GI.

Acid

The naturally occurring acids in fruits, as well as the acids in fermented foods like yogurt, buttermilk, and sourdough bread, slow the rate of digestion and contribute to the low GI of these foods.  Likewise, adding just 4 teaspoons of vinegar or lemon juice to a meal can lower the GI of the meal by about 30 percent.  For this reason, using vinegar and lemon juice to flavor foods can be a powerful way to lower the GI of your diet.

Fiber

Oats, barley, legumes, and many fruits and vegetables are rich in soluble fibers, which form a thick gel when mixed with water.  This slows their passage through the digestive tract and contributes to the low GI of these foods.  The insoluble fibers that form the outer bran layers of whole grains also slow digestion by making it more difficult for digestive enzymes to attack the starches within these foods.  However, when whole grains are ground into fine flours this effect is lost.

Fat

The presence of fat lowers the GI of a food or meal by slowing the rate at which it leaves the stomach.  This is why potato chips and French fries have lower indexes than a plan baked potato.  This does not mean that high-fat chips and fries are better choices than plain baked potatoes or that you should add butter to bread to lower its GI.  When you turn a potato into chips or fries, the added fat doubles the calories.  And the fat used to make these foods is usually the hydrogenated artery-clogging type.  There are far better ways to lower the GI of your diet than adding fat.

Applying the GI to Everyday Life

In real life, people eat mixed meals containing several different foods.  So how do you know what the GI of your entire meal is?  While protein, fat, and other food constituents can influence the GI of a meal, the type and amount of carbohydrate present in the meal is by far the major determinant of the meal GI.  In fact, researchers have shown that the carbohydrate portion of the meal predicts 80 to 90 percent of the meal GI and insulin response, even for meals that contain some protein and fat.  This knowledge makes it possible to estimate the GI of mixed meals based on the GIs of the carbohydrate foods in the meal instead of performing cumbersome laboratory tests.

Realize that it’s not necessary or recommended that you try to calculate the GI of your meals.  Just know that this is how researchers estimate the GI of mixed meals, diets, and recipes and that this method offers a very good prediction of how a meal will affect blood sugar and insulin levels.  The two key points to take from this are:

  • The GI of a meal reflects the types and amounts of all the carbohydrate-containing foods in the meal.
  • You can reduce the impact of a high-GI food in a meal by balancing it out with lower-GI foods in the same meal.

The glycemic index can be an effective tool for choosing foods that minimize fluctuations in blood glucose and insulin levels and thus maintaining good health and optimal weight.  A variety of factors affect the glycemic response of individual foods and mixed meals, and becoming familiar with these will help you apply the glycemic index to your everyday life.

A large selection of foods can be enjoyed on a low-GI eating plan, and choosing more foods that are both high in nutrients and low on the glycemic index can put you on the road to excellent health.

Reference: All Carbohydrates are not Created Equal. Woodruff, S., M.S., R.D.

Category

Name

GI Score

Vegetables & Beans

Baked Beans, 4oz.

48

Kidney beans, 3 oz.

27

Lima beans, 3 oz.

32

Navy beans, 3 oz.

38

Pinto beans, 4oz.

45

Soy beans, 3 oz.

18

Beets, 3 oz.

64

Tomato Sauce

49

Peas

48

Sweetcorn

48

Broccoli, cauliflower, celery, mushrooms

10-25

Breads

Dark rye, 1.7 oz.

51

French baguette, 1 oz.

95

Hamburger bun, 1 bun

61

Kaiser roll, 1

73

Pita bread – whole wheat, 1 slice

57

Sourdough, 1 slice

52

Fruit Bread

53

White bread, 1 slice

70

Wheat bread – stoneground, 1 slice

53

Whole wheat, 1 slice

69

Bagel, plain, 2 oz.

72

Wholegrain Bread

40

Multigrain Breads

45

Meats*

see bottom for more comments

Sweet & Sour Chicken with Noodles

41

Lean Cuisine, French style Chicken

36

Beef casserole

53

Cereals

All-Bran Kellogs, 1/2 cup

42

Bran Flakes, Post, 2/3 cup

74

Cheerios, 1 cup

74

Cocoa Krispies, 1 cup

77

Corn Chex, 1 cup

83

Corn Flakes, 1 cup

84

Corn Pops, 1 cup

80

Cream of Wheat, 1 oz.

74

Frosted Flakes, 3/4 cup

55

Grapenuts Flakes, 3/4 cup

80

Mini Wheats, 1 cup

58

Multi Bran Chex, 1 cup

58

Museli, 2/3 cup

43

Raisin Bran, 3/4 cup

73

Rice Chex, 1 1/4 cup

89

Shredded Wheat, 1/2 cup

83

Smacks, 3/4 cup

56

Special K, 1 cup

54

Total, 3/4 cup

76

Rice

Barley, pearled, 1/2 cup

25

Couscous, 1/2 cup

65

Instant, 1 cup, cooked

87

Uncle Bens, converted, 1 cup

44

Long grain White, 1 cup

56

Short grain, white, 1 cup

72

Cookies

Graham crackers

74

Oatmeal cookie, 1 cookie

55

Vanilla wafers, 7 cookies

77

Crackers

Rice cakes, plain, 3 cakes

82

Stoned wheat thins, 3 crackers

67

Water cracker, 3 crackers

78

Dairy

Ice cream, vanilla, 10% fat

61

Low Fat Ice Cream

35

Milk, whole, 1 cup

27

Milk, skim, 1 cup

32

Milk, chocolate, 1 cup, 1%

34

Pudding, 1/2 cup

43

Milk, soy, 1 cup

31

Tofu frozen dessert, low fat, 1/2 cup

115

Yogurt, nonfat, fruit, sugar, 8 oz.

33

Yogurt, nonfat, plain, artifical sweet, 8 oz.

14

Yogurt, nonfat, fruit, artificial sweet, 8 oz.

14

Custard, 3/4 cup

43

Fruits

Apple, 1 medium, 5 oz.

38

Apple juice, unsweetened, 1 cup

40

Apricots, 3 medium, 3 oz.

57

Banana bread, 3 oz.

47

Banana, 5 oz.

55

Cherries, 10 large, 3 oz.

22

Cranberry juice, 8 oz.

52

Grapefruit, raw, 1/2 medium

25

Grapes, green, 1 cup

46

Kiwi, 1 medium

52

Mango, 1 small

55

Orange, 1 medium

44

Orange juice, 1 cup

46

Peach, 1 medium

30

Pear, 1 medium

38

Pineapple, 2 slices

66

Plums, 1 medium

69

Prunes, 6

29

Raisins, 1/4 cup

64

Watermelon, 1 cup

72

Pasta

Fettucine, 6 oz.

45

Linguine, 6 oz.

46

Macaroni, 5 oz.

45

Ravioli, meat, 4 large

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