Glycemic Index vs. Glycemic Load
Q. I’ve been hearing the terms glycemic index and glycemic load. Are they the same thing or are they different?
A. Glycemic index and glycemic load are two similar but different terms. Glycemic index indicates how rapidly a certain food increases blood sugar after eating, compared to the same amount of carbohydrate as white bread (50 grams of carbohydrate). Glycemic load, on the other hand, takes into account the glycemic index of a food multiplied by the carbohydrate content of the food. For most foods, the rule follows that a food with a high glycemic index will also have a high glycemic load. However, there are exceptions to the rule; carrots and watermelon have high glycemic index but a low glycemic load, due to the small amounts of carbohydrate found in these foods.
Glycemic Index of Foods
Q. Where can I get information about the glycemic index of foods?
A. More information about the glycemic index of foods can be found in the Carbohydrate section of this website, in Dr. Walter Willett’s book Eat, Drink and Be Healthy, and on the University of Sydney’s Glycemic Index website.
Artificial Sweeteners and the Glycemic Index
Q. Where do sugar free products or sugar substitutes like Nutrasweet fall in the glycemic index and in the Healthy Eating Pyramid?
A. Consuming foods made with Nutrasweet-especially beverages-are a better option than consuming sugary drinks. Aspartame does not have a high glycemic index, since it is not a carbohydrate. However, foods and beverages with sugar substitutes should be limited since the lifelong effects of these products are unknown.
Carbohydrates and Weight Loss
Q. Is it true that a high carbohydrate diet is likely not advantageous to weight loss and weight control?
A. It is true that a high carbohydrate diet is likely not advantageous to weight loss, and more importantly to long-term weight maintenance. This is because high carbohydrate diets also tend to be low in fat. In the past two decades, there has been a tremendous focus on low fat diets. In turn, food manufacturers have produced low fat foods that are also high in refined carbohydrates and therefore tend to have a high glycemic index promoting more fat synthesis and storage. In addition, it is important to realize that fat is an important component of a meal. Fat helps to make you feel fuller more quickly, as well as add flavor to meals. Furthermore, plant oils also contain “healthy” fats rich in monounsaturated and polyunsaturated fats.
The aim of the Harvard School of Public Health Nutrition Source is to provide timely information on diet and nutrition for clinicians, allied health professionals, and the public. The contents of this Web site are not intended to offer personal medical advice. You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this Web site. The information does not mention brand names, nor does it endorse any particular products.