Understanding the Glycemic Index
Let’s understand all of the terminology around the glycemic index.
Glycemic Index is a ratio used to measure the relative ability of a carbohydrate to raise blood glucose compared with the ability of glucose to raise blood glucose.
Glycemic Load takes into consideration the portion size of your meal, the grams of carbohydrates in that meal and the glycemic index. Calculating the glycemic load can be time consuming and may not be necessary for most people.
High Glycemic Index foods have a glycemic index of 70 or more. Some examples of foods with a high glycemic index are white bread, honey, potato without the skin and white rice. These foods should not be consumed on a regular basis and can be easily substituted with other medium- and low-glycemic index foods.
Medium Glycemic Index foods are those between 55 and 70. Most fruits, like apricots, bananas, peaches and pineapples, are medium-glycemic index foods. Other examples of medium-glycemic index foods are brown rice, oatmeal and whole wheat pasta.
Low Glycemic Index foods are those with a glycemic index of less than 55. Most of these foods have a higher fiber content and usually come from foods like carrots, barley and apples.
The Glycemic Index and Blood Sugar Control
The buzz around the glycemic index has been going on for many years. Most people should pay attention to the glycemic index values on a superficial level. This means that you should make sure to follow the general recommendations, but do you need to calculate every foods glycemic load and how it will effect your sugar on a meal to meal basis – probably not unless you need to do it for health reasons.
Carbohydrates break down into sugar, but the rate at which they breakdown depends on the type of carbohydrate. There are two types of carbohydrates: simple and complex. Simple carbohydrates are those that break down at a relatively fast rate and are quickly released into your blood stream. Simple carbohydrates result in more inconsistent blood sugars which leave you with highs and lows that trigger cravings for more sugar. Simple carbohydrates are table sugar, cookies, cakes, juices, white bread and white rice which are higher on the glycemic index.
Complex carbohydrates are those carbs that contain fiber. Complex carbohydrates are foods like vegetables, whole wheat pasta and quinoa which are lower on the glycemic index. When consumed these cabohydrates are harder for the body to breakdown due to their fiber content. Since the digestion process of these foods is harder the body releases the sugar more slowly into the blood stream. This results in more stable blood sugars which in turn results in more satiety and less unnecessary eating.
The glycemic index of a food will effect your blood sugar, but it is not the only contributing factor to blood sugar control. Level of daily activity, exercise, hydration, timing of meals, and meal balance all play a role in whether or not your blood sugar will be in good control. It is important to be familiar with the glycemic index values, but you do not need to solely plan every meal and snack around them.
Message from the RD
Carbohydrates are either your best friend or your worst enemy. Understanding carbohydrates and the effect they have on your blood sugar will help you fuel your body optimally. The level at which you choose to use the glycemic index is upto you, but just know that even the smallest of changes to your diet may alter how you feel and promote better blood sugar control. Using the glycemic index values to determine which foods you will consume is a great way to manage your intake and make healthier food choices.
The Glycemic Index www.glycemicindex.com
Wardlaw, G.M. Perspectives in Nutrition, Fourth Edition, 1999.