The Glycemic Index and the Glycemic Load?

The Glycemic Index and the Glycemic Load?

Not all carbohydrate foods are created equal. In fact, they behave quite differently in our bodies. The glycemic index (GI) describes this difference by ranking carbohydrates according to their effect on our blood glucose levels. Eating a lot of high GI foods can be detrimental to your health because it pushes your body to extremes. This is especially true if you are overweight and sedentary. Switch to eating mainly low GI carbs (the ones that produce only small fluctuations in our blood glucose and insulin levels) is the secret to long-term health; thus reducing your risk of heart disease and diabetes which is the key to sustainable weight-loss.

  • Low GI means a smaller rise in blood glucose levels after meals
  • Low GI diets can help people lose weight
  • Low GI diets can improve the body’s sensitivity to insulin
  • High GI foods help re-fuel carbohydrate levels after exercise
  • Low GI can improve diabetes control
  • Low GI foods keep you fuller for longer

What is the Glycemic Load?

The glycemic index compares the potential of foods containing the same amount of carbohydrate to raise blood glucose. However, the amount of carbohydrate consumed also affects blood glucose levels and insulin responses. The glycemic load of a food is calculated by multiplying the glycemic index by the amount of carbohydrate in grams provided by a food and dividing the total by 100.
Dietary glycemic load is the sum of the glycemic loads for all foods consumed in the diet. The concept of glycemic load was developed by scientists to simultaneously describe the quality (glycemic index) and quantity of carbohydrate in a meal or diet.
Glycemic load builds on the GI to provide a measure of total glycemic response to a food.

  • Glycemic load = GI (%) x grams of carbohydrate per serving and dividing the total by 100
  • One unit of GL ~ glycemic effect of 1 gram glucose
  • You can sum the GL of all the foods in a meal, for the whole day or even longer
  • A typical diet has ~ 100 GL units per day (range 60 – 180)
  • The GI database gives both GI & GL values

In the first two hours after a meal, blood glucose and insulin levels rise higher after a high-glycemic load meal than they do after a low-glycemic load meal containing equal calories. However, in response to the excess insulin secretion, blood glucose levels drop lower over the next few hours after a high-glycemic load meal than they do after a low-glycemic load meal. This may explain why 15 out of 16 published studies found that the consumption of low-glycemic index foods delayed the return of hunger, decreased subsequent food intake, and increased satiety (feeling full) when compared to high-glycemic index foods. The results of several small short-term trials (1-4 months) suggest that low-glycemic load diets result in significantly more weight or fat loss than high-glycemic load diets. Although long-term randomized controlled trials of low-glycemic load diets in the treatment of obesity are lacking, the results of short-term studies on appetite regulation and weight- loss suggest that low glycemic-load diets may be useful in promoting long-term weight-loss, decreasing obesity and Type 2 Diabetes.

View our table of Low-Glycemic Index Foods