Can I plan my meals using only the glycemic index?

While the Glycemic Index can be incorporated into your diabetic meal planning, it is just one tool you can use. To learn more, ask your health care provider for a referral to a registered dietitian who also specializes in diabetes – this person is called a Certified Diabetes Educator (CDE).
Constance Brown-Riggs
Nutrition & Dietetics

The glycemic index (GI) can be part of your strategy when planning healthy meals. The GI measures how fast a particular carbohydrate raises blood sugar as compared to a standard amount of glucose. Foods with a high GI will raise your blood sugar quickly and low GI foods, which are absorbed more slowly, will raise your blood sugar more slowly.

Sound pretty straight forward? Unfortunately, it’s a little more complicated than it seems. Even foods with the same carbohydrate content can affect your blood sugar differently, depending on the GI of the food. The preparation and processing of the food are other variables. For instance, a boiled potato has a lower GI than a baked potato and basmati rice, long-grain white rice and brown rice have different GIs.

The GI of a food is not an indicator of the food’s nutrient profile. All too often people eliminate healthy foods because of a high GI. For example, carrots have a high GI but have tremendous health benefits. French fries on the other hand have a lower GI than a baked potato. I think you get the picture.

While complicated the GI is not impossible to follow. If you decide to use the GI as part of your meal planning strategy consider the following;

  • Remember that low GI does not mean the food item is healthy. So, look at the total nutrition of a food.
  • Combining high GI foods with protein or fat can actually lower the GI. For example, have a baked potato topped with low-fat chili.
  • Foods high in fiber tend to have a lower GI. So be sure to include whole grains in your meals.
  • Eat lots of fresh fruit and vegetables, most of which are low GI foods.
  • If you have diabetes portion size is as critical as the GI. The more you eat, the higher your blood glucose will go regardless of the GI of the food.
  • Develop your own GI. Check your blood glucose levels two hours after a meal to find out how your body deals with a food or meal.
  • Slowing digestion will lower the GI. Instead of creamy dressings use vinegar based dressing; they will slow digestion without the added fat calories.



Toby Smithson
Nutrition & Dietetics

Here are the pros and cons of the GI (Glycemic Index) and GL (glycemic load): 

Pros: The GI and GL may help fine tune blood sugar levels, particularly peaks; It may help keep blood sugar closer to normal range throughout the day instead of having a roller coaster effect from eating a food that raises your blood sugar quickly. Using the GI makes it easier to balance blood sugar by balancing the low GI foods with high GI foods in the same meal; The GI is another tool to keep in your diet toolbox.

Cons: The GI has been put together based on one particular food and not in combination with other foods such as in a meal; A GI is established for a particular food by monitoring blood glucose levels among people with normal glucose metabolism (i.e., not people with diabetes who may not respond in the same manner); Since the BG response is a picture of both blood glucose rising from the subject food and lowering (or staying lower) from an insulin response, people with diabetes could misinterpret the ultimate BG level of low GI foods (i.e., the BG level depends upon the insulin response, which PW Type 1 must supply and PW Type 2 may be dysfunctional); Serving size is not taken into account with the GI….carrots, for instance, have a very high GI, but the carb content is very low for normal serving sizes; Some foods with a high GI are healthy food choices and shouldn’t be discounted or avoided in the diet because of their GI or GL number; This is just one tool and needs to be combined with a meal plan whether it is carb counting or the exchange system; it should not be confused with what number to use when blousing with insulin or in comparing to a meal plan. The GL number should not be confused with the carbohydrate amount or carb choice. Even though some fresh fruit has a low GI, it doesn’t mean you can have all that you want. If we use the example of an apple which has 15 grams of carbohydrate, or 1 carb choice per serving, the GL is 6 grams (15 X 40 GI/100 ). A PWD may confuse the numbers to only account for 6 grams of carbohydrate ingested; There are other factors that will play a role in the slow or rapid rise of blood glucose after eating carbohydrate containing food- fiber content; raw versus canned or cooked; ripeness of produce; how long the carbohydrate food is cooked; and sometimes the variety of the carbohydrate food. A whole meal will likely include protein and fat as well.


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    Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.