The Glycemic Index vs. Glycemic Load: Which Matters More for Diabetics?

People who manage diabetes need to learn how various foods influence their blood sugar levels because this knowledge forms the basis for their daily management. The terms Glycemic Index (GI) and Glycemic Load (GL) appear frequently in discussions but understanding their differences remains unclear to many people. The two tools predict blood sugar response from carbohydrate foods but they present different information about these effects. So, which one should you pay more attention to for better diabetes control? The article describes the differences between Glycemic Index and Glycemic Load and identifies which measurement works better for daily use while giving practical advice for healthy eating. The Glycemic Index (GI) functions as a measurement system which evaluates carbohydrate foods based on their ability to quickly increase blood sugar after consumption. The Glycemic Index works as a system which measures carbohydrate foods from 0 to 100 to show how fast they increase blood glucose after eating. The comparison of foods happens against pure glucose which serves as the reference food because it has a GI value of 100. [1] High-GI foods (70 or more): The body quickly processes these foods which leads to fast blood sugar spikes. The list contains white bread and potatoes and sugary cereals. Medium-GI foods (56-69): These foods have a moderate impact on blood sugar. Examples include brown rice and sweet corn. The digestion and absorption process of Low-GI foods (55 or less) happens at a slower pace which results in a steady and moderate increase of blood sugar levels. The list contains non-starchy vegetables together with lentils and beans and whole grains. The GI system allows people to start learning but it fails to show the typical carbohydrate content that exists in standard food portions. This is where the Glycemic Load comes in. What is the Glycemic Load (GL)? The Glycemic Load (GL) is a more comprehensive measure that considers both the Glycemic Index of a food and the amount of carbohydrates in a specific serving. The measurement system provides precise results about how different foods affect blood sugar levels in real life situations. The formula for calculating Glycemic Load is: GL = (GI of a food × Grams of carbohydrates per serving) / 100 High-GL foods (20 or more): These foods will likely cause a large and rapid rise in blood sugar. The glycemic index between 11 and 19 for these foods produces moderate effects on blood sugar levels. The glycemic index values for these foods range from 10 or lower which causes them to produce slow and gradual effects on blood sugar levels. The following example demonstrates the situation with watermelon. Watermelon has a high GI of around 72. Based on GI alone, you might think it’s a food to avoid. A typical serving of watermelon consists mostly of water but it contains just 11 grams of carbohydrates in one cup. The Glycemic Load value for this food remains low because GL = (72 × 11) / 100 = 7.9. Watermelon qualifies as a low-GL food because its GL value stands at 7.9 which means it produces minimal blood sugar effects when eaten in typical serving sizes. [2] Glycemic Index vs. Glycemic Load: What’s the Difference? Here is a simple table to clarify the key distinctions: Feature Glycemic Index (GI) Glycemic Load (GL)What it MeasuresHow quickly a food raises blood sugarThe total impact of a food on blood sugarFactors ConsideredType of carbohydrateType and amount of carbohydrate per servingPrimary UseComparing the quality of carbohydratesAssessing the real-world effect of a food portionPracticalityLess practical, as it ignores serving sizeMore practical for daily meal planningWhich is More Important for Diabetes Management?The Glycemic Load serves as the preferred method for diabetes management according to nutrition experts because it provides more accurate results than other methods. [3] It provides a more realistic assessment of how a particular food, in the amount you actually eat, will affect your blood sugar. The total number of carbohydrates in your meal determines your blood sugar results more than any other factor. [1] Focusing solely on GI or GL without considering total carb intake can be misleading. For example, a large portion of a low-GL food can still raise your blood sugar more than a small portion of a high-GL food. The key is to use these tools as part of a balanced approach that prioritizes portion control and overall carbohydrate management. The following section provides practical guidance for using GI and GL. Focus on low-glycemic eating principles instead of numbers. Ground your food choices in whole unprocessed items which include non-starchy vegetables and fruits and legumes and whole grains. The natural composition of these foods results in lower GI values because fiber content slows down the absorption of sugar. When you eat a food with a high glycemic index you should eat it together with protein or healthy fat or fiber. The blood sugar response decreases when you combine chicken and avocado with rice in a meal. Be Mindful of Portions: Even healthy, low-GL foods should be consumed in appropriate portions. The plate method functions as an easy system to divide your plate into three sections which include half non-starchy vegetables and one-quarter protein and one-quarter high-fiber carbohydrates. Read Labels: The “Total Carbohydrates” section on nutrition labels helps you track your carbohydrate intake better. The Glycemic Index system provides basic information about carbohydrate quality but the Glycemic Load system delivers practical and precise predictions about how foods affect blood sugar levels. The selection of low-GL foods combined with proper carbohydrate monitoring enables you to make better dietary decisions which result in stable blood sugar levels and enhanced wellness. The search for a single metric to solve all problems continues. A successful diabetes management plan requires people to follow a balanced diet while staying active and monitoring their blood sugar levels regularly. Your doctor or registered dietitian will provide you with personalized advice. References Harvard T.H. Chan School of Public Health. (2023). The lowdown on glycemic index and glycemic load . https://www.health.harvard.edu/diseases-and-conditions/the-lowdown-on-glycemic-index-and-glycemic-load Oregon State University, Linus Pauling Institute. (2023). Glycemic Index and Glycemic Load . https://lpi.oregonstate.edu/mic/food-beverages/glycemic-index-glycemic-load Vlachos, D., et al. (2020). Glycemic Index (GI) or Glycemic Load (GL) and Dietary Interventions for Optimizing Postprandial Hyperglycemia in Patients with T2 Diabetes . Nutrients , 12(6), 1561. https://pmc.ncbi.nlm.nih.gov/articles/PMC7352659/