The Glycemic Index
Studies have shown that it's not just how much carbohydrate you eat that affects blood sugar, but the source of the carbohydrates as well. Some foods cause a quick rise in blood sugar after a meal, while others cause a smaller peak and more gradual decline in blood sugar levels. The measure of how fast a food causes blood sugar to peak is called its "glycemic index" or GI.
What the GI Means
High-carbohydrate foods are ranked on a scale of 1 to 100, with 100 representing the effect of pure glucose on the body. The lower a food's GI, the slower its peak.
Foods are then broken into three categories. Because they're low in carbohydrates, meats and fats are not ranked.
Low-GI foods GI less than 55
Intermediate GI between 55 and 70
High-GI GI above 70
So French bread, with a GI of 95, causes a faster, greater spike in blood sugar than stone-ground whole wheat bread with a GI of 53.
A few low-GI foods include:
• whole grain breads and cereals
• brown rice
• dried beans and lentils
• old-fashioned oatmeal
• sweet potatoes
• dairy products
• apples and oranges
Using the Glycemic Index
Used in combination with carbohydrate counting, the glycemic index may help you stabilize your blood sugars throughout the day. The rule of thumb is that the higher the GI, the smaller the portion you should have. On the flip side, you can eat more of lower-GI foods without overloading your blood sugar.
There are a number of books available in stores and online, in which you can find lists of foods and their GIs. Then you can start choosing foods from the low-GI category more often and see if it helps you maintain closer-to-normal blood sugar levels.