Nutritional Health for Women

Page 2

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

Learning to prevent large swings in blood sugars to improve a sense of well-being and performance is a valuable lesson in nutrition. A food's glycemic index can sometimes be surprising: white flour, white bread, and white rice have a high glycemic index, but whole-wheat flour, whole-wheat bread, and brown rice have a lower index. Starchy foods such as white potatoes, corn, and carrots also have a high glycemic index, although sweet potatoes, peas, and celery do not. The best way to incorporate the glycemic index into your lifestyle is to purchase a book that lists common foods (refer to "Resources" at the end of this book). The glycemic index of foods can also be lowered by eating them with foods that slow their digestion, specifically fat, protein, or fiber. For example, eating corn with butter or potatoes with meat lowers the glycemic index. You can also lower glycemic index of pastas and rice by cooking them al dente (firm, not overcooked, and mushy). The following is a chart of some common foods. Basically, low glycemic index foods have GIs less than 55, medium are 55 to 74 and high are 75 to 100.

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

Fiber
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 daily—such 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