Glycemic Index -Importance of it
You might have heard the words “glycemic
index” being thrown around, but weren't sure what the whole thing was
about. The glycemic index (GI) is a number that is associated with
different foods and shows their effect on the glucose levels in the
blood (also known as “blood sugar level”). The number represents the
total rise in glucose level after eating that food.
How the GI is determined:
The level of “sweetness” of a food doesn’t necessarily give it a low or
high GI value- Foods with simple carbohydrates break down faster in the
stomach, releasing glucose into the blood more rapidly and therefore
have a higher GI value. Foods with complex carbohydrates, which break
down slower, will have a lower GI value.
Other factors that affect GI levels:
Dietary fiber, fat, protein, vinegar and amylose starch will lower the
GI levels in food. Research shows that consuming a small amount of
alcohol shortly before a meal will reduce the GI level of the meal by
15%.
GI classification:
Classification GI range Examples
Low GI - 55 or less beans (white, black, pink, kidney, lentil, soy,
almond, peanut, walnut, chickpea); small seeds (sunflower, flax,
pumpkin, poppy, sesame); most whole intact grains (durum/spelt/kamut
wheat, millet, oat, rye, rice, barley); most vegetables, most sweet
fruits (peaches, strawberries, mangos); fructose; mushrooms; chili
peppers
Medium GI 56-69 - Whole wheat or enriched wheat (not-intact), pita
bread, basmati rice, unpeeled boiled potato, grape juice, raisins,
prunes, pumpernickel bread, cranberry juice, regular ice cream, sucrose,
banana
High GI 70 or higher-- white bread (only wheat endosperm), most white
rice (only rice endosperm), corn flakes, extruded breakfast cereals,
glucose, maltose, maltodextrins, potato, pretzels, bagels
Why do we need to know the GI of food?
Diabetics need to know what their glucose levels are, as changes in
these levels can have serious effects on their physical and mental state
and may even be detrimental to their health. Non-diabetics can use the
GI to better regulate their energy levels and improve results when
working out. Some people with a thyroid condition need to control their
blood sugar levels in order to lose or maintain weight.
High glycemic foods break down fast, providing a quick energy boost,
especially after a workout. Low glycemic foods take more time to break
down, making them great fuel to have before a workout, as they release
energy into the body in a steady rate. These factors can help you
prevent hypoglycemia symptoms.
A 1999 research discovered that people who follow a low GI diet over a
prolonged period of time reduce the risk of developing coronary heart
disease, type 2 diabetes and even age-related muscular degeneration.
Things to be aware of:
The GI index is not perfect – there are
many foods that are low-glycemic which are unhealthy (Chocolate cake –
GI 31, ice cream – GI 37) and ones that are high-glycemic that are good
for you (Potato/rice – 100 GI). Remember to practice moderation.
The amount of carbohydrates in food can
have more of an impact than GI on the glucose levels in your blood.
Losing weight and consuming less carbs will also lower blood glucose
levels.
The Rise of Blood Sugar Levels After a Meal
The Harvard Medical School recently published a glycemic index of common foods:
FOOD
GI
(glucose = 100) Serving size (grams) Glycemic load per serving
BAKERY PRODUCTS AND BREADS
Banana cake, made with sugar 47 60 14
Banana cake, made without sugar 55 60 12
Sponge cake, plain 46 63 17
Vanilla cake made from packet mix
with vanilla frosting (Betty Crocker) 42 111 24
Apple, made with sugar 44 60 13
Apple, made without sugar 48 60 9
Waffles, Aunt Jemima (Quaker Oats) 76 35 10
Bagel, white, frozen 72 70 25
Baguette, white, plain 95 30 15
Coarse barley bread, 75-80% kernels 34 30 7
Hamburger bun 61 30 9
Kaiser roll 73 30 12
Pumpernickel bread 56 30 7
50% cracked wheat kernel bread 58 30 12
White wheat flour bread 71 30 10
Wonder™ bread 73 30 10
Whole wheat bread 71 30 9
100% Whole Grain™ bread
(Natural Ovens) 51 30 7
Pita bread, white 68 30 10
Corn tortilla 52 50 12
Wheat tortilla 30 50 8
BEVERAGES
Coca Cola® 63 250 mL 16
Fanta®, orange soft drink 68 250 mL 23
Lucozade®, original
(sparkling glucose drink) 95±10 250 mL 40
Apple juice, unsweetened 44 250 mL 30
Cranberry juice cocktail
(Ocean Spray®) 68 250 mL 24
Gatorade 78 250 mL 12
Orange juice, unsweetened 50 250 mL 12
Tomato juice, canned 38 250 mL 4
BREAKFAST CEREALS AND RELATED PRODUCTS
All-Bran™ 55 30 12
Coco Pops™ 77 30 20
Cornflakes™ 93 30 23
Cream of Wheat™
(Nabisco) 66 50 17
Cream of Wheat™,
Instant (Nabisco) 74 250 22
Grapenuts™ 75 30 16
Muesli 66 30 16
Oatmeal 55 250 13
Instant oatmeal 83 250 30
Puffed wheat 80 30 17
Raisin Bran™ (Kellogg's) 61 30 12
Special K™ (Kellogg's) 69 30 14
GRAINS
Pearled barley 28 150 12
Sweet corn on the cob 60 150 20
Couscous 65 150 9
Quinoa 53 150 13
White rice 89 150 43
Quick cooking
white basmati 67 150 28
Brown rice 50 150 16
Converted, white rice
(Uncle Ben's®) 38 150 14
Whole wheat kernels 30 50 11
Bulgur 48 150 12
COOKIES AND CRACKERS
Graham crackers 74 25 14
Vanilla wafers 77 25 14
Shortbread 64 25 10
Rice cakes 82 25 17
Rye crisps 64 25 11
Soda crackers 74 25 12
DAIRY PRODUCTS AND ALTERNATIVES
Ice cream, regular 57 50 6
Ice cream, premium 38 50 3
Milk, full fat 41 250mL 5
Milk, skim 32 250 mL 4
Reduced-fat yogurt
with fruit 33 200 11
FRUITS
Apple 39 120 6
Banana, ripe 62 120 16
Dates, dried 42 60 18
Grapefruit 25 120 3
Grapes 59 120 11
Orange 40 120 4
Peach 42 120 5
Peach, canned
in light syrup 40 120 5
Pear 38 120 4
Pear, canned
in pear juice 43 120 5
Prunes, pitted 29 60 10
Raisins 64 60 28
Watermelon 72 120 4
BEANS AND NUTS
Baked beans 40 150 6
Blackeye peas 33 150 10
Black beans 30 150 7
Chickpeas 10 150 3
Chickpeas,
canned in brine 38 150 9
Navy beans 31 150 9
Kidney beans 29 150 7
Lentils 29 150 5
Soy beans 15 150 1
Cashews, salted 27 50 3
Peanuts 7 50 0
PASTA and NOODLES
Fettucini 32 180 15
Macaroni 47 180 23
Macaroni and
Cheese (Kraft) 64 180 32
Spaghetti, white,
boiled 46 180 22
Spaghetti, white
boiled 20 min 58 180 26
Spaghetti,
wholemeal, boiled 42 180 17
SNACK FOODS
Corn chips,
plain, salted 42 50 11
Fruit Roll-Ups® 99 30 24
M & M's®, peanut 33 30 6
Microwave
popcorn, plain 55 20 6
Potato chips 51 50 12
Pretzels,
oven-baked 83 30 16
Snickers Bar® 51 60 18
VEGETABLES
Green peas 51 80 4
Carrots 35 80 2
Parsnips 52 80 4
Baked russet
potato 111 150 33
Boiled white
potato 82 150 21
Instant mashed
potato 87 150 17
Sweet potato 70 150 22
Yam 54 150 20
MISCELLANEOUS
Hummus (chickpea
salad dip) 6 30 0
Chicken nuggets
(frozen) 46 100 7
Pizza (plain baked dough,
parmesan cheese and
tomato sauce) 80 100 22
Pizza, Super Supreme
(Pizza Hut) 36 100 9
Honey 61 25 12