Use the glycemic index to keep weight down and energy up

Lowering the amount of refined carbohydrates in the diet is a better strategy for controlling weight than cutting out fat. A good way to manage carbs is with the glycemic index, reports the December 2014 Harvard Women's Health Watch.

The glycemic index, developed more than 30 years ago, measures the ease with which your body turns carbohydrates into blood sugar. The higher a food's glycemic index, the faster the sugars in the food get into the blood. Foods with a lower glycemic index make the body work harder to extract the sugars, so glucose enters the blood slowly and steadily. That helps ward off hunger longer. A glycemic index between 0 and 55 is considered low, 56 to 69 is medium, and 70 or higher is high. White rice, for example, has a glycemic index around 90, compared to 30 for whole wheat grains.

"The glycemic index is the best measure we have today of how rapidly carbohydrate gets digested into glucose," explains Dr. David Ludwig, director of the New Balance Foundation Obesity Prevention Center at Harvard-affiliated Boston Children's Hospital.

Dr. Ludwig and his team found that people on a low-glycemic diet burn more calories than those on a high-glycemic diet. The team also determined that low-glycemic meals are less likely to leave you hungry and craving a snack a few hours later than high-glycemic meals containing the same number of calories.

Another measure, the glycemic load is also good to use. It takes into account both the glycemic index of a food and the carbohydrate content in a serving. Although some foods, like watermelon, have a high glycemic index, they have a moderate glycemic load because a serving has relatively few carbohydrates. Foods like white potatoes, that are both high-glycemic and high-carb, pack a greater glycemic load.

Interested in using the glycemic index? Try these tips for replacing high-glycemic foods with low-glycemic foods:

  • Avoid processed starches and sugars. In other words, approach the center aisles of the grocery store with caution. Pass up "quick-cooking" or "instant" rice or grains and most cold cereals. Steel-cut oats, wheat berries, and brown rice are good alternatives.
  • Buy fresh fruit instead of juice. Not only are several fruits required to make a glass of juice, when fruit is squeezed, the cells are broken open, releasing the sugars. A 6-ounce glass of apple juice has a much higher glycemic load than a 6-ounce apple.
  • Check out the chart at for the glycemic index and glycemic load of 100 common foods.

Read the full-length article: "Keep your weight down and energy up with the glycemic index"

As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.