In This ArticleView AllIn This ArticleUnderstanding Glycemic IndexUnderstanding Glycemic LoadKey DifferencesWhich One Should You Use?

In This ArticleView All

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In This Article

Understanding Glycemic Index

Understanding Glycemic Load

Key Differences

Which One Should You Use?

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an illustration of various foods and the glycemic index graph behind them

Getty Images. EatingWell design.

If you have diabetes or prediabetes, you may have come across terms like “glycemic index” (GI) and “glycemic load” (GL) when putting together ablood sugar-friendly diet, but understanding what they are and distinguishing between the two is important. Although they sound the same, there are key differences between them.

If you’re focused onbetter blood sugar control, glycemic load is a better choice. Keep reading to learn why.

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The glycemic index is a ranking system that measures how quickly carbohydrate-containing foods raiseblood sugar levels. Foods are scored from 0 to 100, with pure glucose, at 100, representing the fastest blood sugar spike.

Foods with a high GI (above 70) are quickly digested and can cause rapid rises in blood sugar. These include simple carbs like white bread, white rice, instant oats and sugary snacks. Conversely, low-GI foods (below 55), including whole foods like lentils, apples and steel-cut oats, release glucose gradually, resulting in a slower, more sustained rise in blood sugar.

That said, there are limits to the application of GI in one’s regular diet. “Glycemic index uses a standardized portion size—usually 50 grams of carbohydrate from a particular food—rather than the typical serving size people would consume,” explainsErin Palinski-Wade, RD, CDCES, a registered dietitian and author of the2-Day Diabetes Diet. “This means GI doesn’t always reflect real-world consumption. For instance, watermelon has a high GI of 80, but a standard serving contains relatively few carbs, so its impact on blood sugar is minimal,” she explains.

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Glycemic Index Categories

Here is a breakdown of the glycemic index categories and some examples.

While GI is useful, it doesn’t account for portion sizes. That’s where glycemic load comes in. GL considers both the GI of a food and the actual amount of carbohydrates in a typical serving.“This provides a more accurate assessment of how a food affects blood sugar,” says Palinski-Wade.

Glycemic Load Categories

Glycemic load categories are as follows:

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Glycemic Index vs. Glycemic Load: Key Differences

Palinski-Wade says, “GI can be misleading if you’re only looking at the numbers. A food with a high GI may have a low GL if eaten in small portions, meaning it will have little impact on blood sugar.”

GL is more practical for real-world eating habits. Take carrots, for example. They have a high glycemic index (85 out of 100), but their glycemic load for a typical serving size is low (4.25), meaning they’re unlikely to cause a significant blood sugar spike.If you were to look at glycemic index alone, you might skip carrots entirely out of worry about their blood sugar effects.

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Glycemic load is more practical when it comes to managing blood sugar levels. “GL more accurately reflects how a food will impact blood sugar levels, because it considers both the food and the portion size consumed,” explains Palinski-Wade.

However, neither GI nor GL are perfect, Palinski-Wade cautions. “What you eat alongside carbohydrate-containing foods—such as protein, fat orfiber—as well as timing, activity level and stress, can all influence blood sugar responses.”

Palinski-Wade recommends tracking your meals and monitoring blood sugar levels to understand better how your food choices impact your blood sugar. “I often advise my clients to use apps like MyFitnessPal to record their food intake and sync it with continuous glucose monitors (CGMs),” she says. “This helps them see real-time correlations between their meals and blood sugar levels, making it easier to adjust their diet for better glucose control.”

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The Bottom Line

For most people, focusing on glycemic load is more practical for real-world eating and blood sugar management. However, the best approach is to regularly monitor your blood sugar levels to understand how specific foods impact you. Speak with your health care provider or a registered dietitian if you have any questions about creating a diet that helps you best manage your blood sugar levels.

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SourcesEatingWell uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable and trustworthy.National Library of Medicine. MedlinePlus.Glycemic index and diabetes.Vlachos D, Malisova S, Lindberg FA, Karaniki G.Glycemic Index (GI) or Glycemic Load (GL) and Dietary Interventions for Optimizing Postprandial Hyperglycemia in Patients with T2 Diabetes: A Review.Nutrients. 2020;12(6):1561. doi:10.3390/nu12061561Zhi-Quan Lu, Jia Yan.Handbook of Nutrition, Diet and the Eye. Academic Press. 2014Glycemic Index Guide.Carrot (cooked).

Sources

EatingWell uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable and trustworthy.National Library of Medicine. MedlinePlus.Glycemic index and diabetes.Vlachos D, Malisova S, Lindberg FA, Karaniki G.Glycemic Index (GI) or Glycemic Load (GL) and Dietary Interventions for Optimizing Postprandial Hyperglycemia in Patients with T2 Diabetes: A Review.Nutrients. 2020;12(6):1561. doi:10.3390/nu12061561Zhi-Quan Lu, Jia Yan.Handbook of Nutrition, Diet and the Eye. Academic Press. 2014Glycemic Index Guide.Carrot (cooked).

EatingWell uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable and trustworthy.

National Library of Medicine. MedlinePlus.Glycemic index and diabetes.Vlachos D, Malisova S, Lindberg FA, Karaniki G.Glycemic Index (GI) or Glycemic Load (GL) and Dietary Interventions for Optimizing Postprandial Hyperglycemia in Patients with T2 Diabetes: A Review.Nutrients. 2020;12(6):1561. doi:10.3390/nu12061561Zhi-Quan Lu, Jia Yan.Handbook of Nutrition, Diet and the Eye. Academic Press. 2014Glycemic Index Guide.Carrot (cooked).

National Library of Medicine. MedlinePlus.Glycemic index and diabetes.

Vlachos D, Malisova S, Lindberg FA, Karaniki G.Glycemic Index (GI) or Glycemic Load (GL) and Dietary Interventions for Optimizing Postprandial Hyperglycemia in Patients with T2 Diabetes: A Review.Nutrients. 2020;12(6):1561. doi:10.3390/nu12061561

Zhi-Quan Lu, Jia Yan.Handbook of Nutrition, Diet and the Eye. Academic Press. 2014

Glycemic Index Guide.Carrot (cooked).