Nutritional Health for Women
The Glycemic Index
Glycemic index, or GI, is an index given to mostly carbohydrate foods based on how quickly they raise blood sugar levels. The index is a number from 0 to 100; the higher the number, the quicker the food reaches the bloodstream as glucose. Sugar has the highest glycemic index (100); soybean one of the lowest (18). Foods with a high glycemic index are often processed, starchy, and sugary foods, although some natural foods, such as honey and watermelon, have high indexes. Foods that contain fat or fiber along with the sugar have lower indexes because the fat and fiber slow the release of glucose. Athletes in particular can use the glycemic index of foods to determine which types of carbohydrates provide the best fuel before and during events and training. High glycemic index food products such as GU or Cliff Shotz or drinks such as Gatorload or Endurox provide quick sources of energy and are useful in long endurance events in which the body has depleted its glycogen supply. High glycemic index carbohydrates need to be eaten frequently during endurance events lasting more than two hours to maintain blood glucose levels and provide energy. Before competition, low to medium glycemic index foods are recommended to promote steady blood glucose over the next one to two hours.
Research has recently suggested that people who regularly eat high glycemic index diets have a greater risk of diabetes, obesity, and heart disease due to a tidal wave of high and low blood sugar levels. High GI foods send a sudden flood of glucose into the blood, which causes the pancreas to release a large amount of insulin, the hormone that transfers blood glucose from the blood and into storage as glycogen or fat. The amount of insulin released corresponds to the amount of blood glucose; high levels of both glucose and insulin can be dangerous to body organs and increase the risk of diabetes. Also, there is a rebound of low blood sugar, which can cause sleepiness, moodiness, irritability, and, in diabetics, coma. Hunger is felt again sooner after high glycemic index foods are eaten due to this low blood sugar.
In contrast, low and medium glycemic index foods cause a slow release of glucose into the bloodstream. Normal amounts of glucose circulate and low amounts of insulin are released in a steady stream. This keeps blood glucose levels stable and protects the body and brain from the dangerous effects of unstable blood sugars. Mood is also stabilized, as brain glucose supplies are constant. In people at risk of diabetes, with a family history or a history of (gestational) diabetes in pregnancy, eating a low to moderate glycemic index diet will reduce the risk of developing diabetes later in life.
The Benefits of Low Glycemic Index Foods
- Fewer hunger pangs
- Stable energy levels
- Steady blood sugars
- Less fatigue
- Stable mood
- Less insulin requirements
|Low GI Foods||Medium GI Foods||High GI Foods|
|Oatmeal 46||Power Bar 58||Jelly beans 80|
|Yogurt, sweetened 34||Ice cream 61||French bread 95|
|Meat ravioli 39||Raisins 64||Waffles 76|
|Soybeans 18||Sweet corn 55||Short-grain white rice 76|
|Milk 30||White rice 60||Corn flakes 87|
|Black beans 31||Pizza 62||Baked potato 90|
|Grapefruit 26||Wheat bread 71||French fries 78|
|Apple 39||Macaroni and cheese 67||Corn chips 76|
|Sweet potato 46||Croissant 70||Donut 78|
|Sponge cake 47||Banana 56||Pretzels 85|
|Fettucini 34||Chocolate 51||Rice cakes 80|
|Orange 46||Oatmeal cookie 58||Sugar, honey, 100|
|Peanuts 15||Popcorn 58||Bagel 75|
|Thin spaghetti 47||Pita bread 57||Watermelon 75|
A high-fiber diet has been recognized for years for its health benefits. Dietary fiber content is very important to long-term health. In fact, it has been identified as a necessary diet nutrient by the Food and Drug Administration (FDA). Fiber is a natural plant product that helps slow digestion, lowering glycemic indexes of foods. Fiber has also been identified for its many health prevention benefits, particularly reduced risk of breast cancer, colon cancer, diabetes, heart disease, constipation, diverticulosis, stroke, hypertension, and obesity.
The Reference Daily Intake (RDI) for fiber, based on a 2,000-calorie diet, is 25 grams/day. This should be your minimum. Because large amounts of fiber, especially if your digestive system is not used to it, can cause bloating, stomach upset, and diarrhea, increasing the overall amount of fiber in your diet should be done gradually with fiber distributed evenly throughout meals and snacks. Products such as Beano can help with gas and bloating if that is a problem. Eating various sources of fiber dailysuch as popcorn, fresh and dried fruits, vegetables, nuts, beans, and whole grains is also recommended. You should also drink plenty of water with fiber, because this will make your stomach feel full for longer. Because of the cleansing effect fiber has on the digestive tract and bowels, avoid high-fiber products the night before, morning of, and during events, unless your body is used to a high-fiber diet.
The Health Benefits of a High-Fiber Diet
- Decreases breast cancer
- Decreases colon cancer
- Decreases cholesterol
- Prevents and manages diabetes
- Prevents heart disease
- Prevents constipation
- Prevents diverticulosis
- Helps prevent stroke
- Prevents high blood pressure
- Helps prevent obesity
- Helps you feel full longer
More on: Planning Healthy Meals for Families
From The Active Woman's Health and Fitness Handbook by Nadya Swedan. Copyright © 2003 by Nadya Swedan. Used by arrangement with Perigee, a member of Penguin Group (USA) Inc.
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