Everything About the Glycemic Index

August 26, 2022

Carbohydrates have a big impact on your blood sugar levels, which in turn have a strong effect on your health. We usually think of carbohydrates just in terms of “simple” or “complex”, but their effects on your blood sugar aren’t that simple. The glycemic index (GI) gives us a better understanding of this relationship. Understanding how carbohydrates affect your blood sugar levels is helpful for managing diabetes, weight, and overall following a healthy diet.

In this article, we’ll explain everything you need to know about the GI and identify some low-, medium-, and high-GI foods.

Overview of the Glycemic Index

The glycemic index is a scale for ranking the number of carbohydrates in foods; it indicates how quickly a food causes your blood sugar to rise. The scale runs from 0 to 100. Pure sugar has a GI of 100. The higher a food’s GI, the faster it makes your blood sugar rise.

Defining GI Scores

Foods can be categorized as low-, medium-, or high-GI. A low-GI food has a GI score of 55 or less. Medium GI foods have a score between 56 and 69. High GI foods are those with a GI score of 70 or above.

However, this is an estimate! There are several factors that can affect the GI of a food. Cooking and processing generally raise the GI of a food. For example, steamed broccoli has a higher GI than raw broccoli and orange juice has a higher GI than a whole orange. Riper foods have higher GI scores than unripe foods. Including foods high in fiber lowers the GI score of a meal.

Another thing to keep in mind is that GI score does not account for how much of a food you are eating at one time. For example, watermelons have a high GI, but you would have to eat an absurdly large quantity of watermelon for it to cause a big spike in your blood sugar.

Glycemic Load

Glycemic load (GL) is a measure that accounts for this by combining portion size and GI. To calculate GL, multiply the carbohydrate content of the serving of food by the food’s GI, then divide that number by 100. A GL of 10 or less is low. A GL between 11 and 19 is moderate. A GL or 20 or above is considered high.

Let’s continue the watermelon example. Watermelon has a GI of 80, which is pretty high. But, the number of carbohydrates in a serving of watermelon is low. So, the GL for watermelon is 5, making it a low-GL food.

Which Foods are Healthier?

Eating high-GI foods can cause your blood sugar to spike and quickly fall. This can make it harder to maintain a healthy weight and manage your hunger because when your blood sugar falls, you start to feel hungry. So, high-GI foods can prompt you to overeat. 

Low-GI foods raise your blood sugar more slowly. Foods that are high in protein, fat, and fiber typically have low GI scores and keep you full for longer. Therefore, low-GI foods are better for regulating blood sugar and cholesterol levels and losing weight. Nutritionists say an average GI score of 45 for a meal will have the most significant benefits for your health. 

Low-GI Foods (≤ 55)

  • Peanuts – 7
  • Greek yogurt – 11
  • Apples – 28
  • Chickpeas – 28
  • Lentils – 32
  • Carrots (boiled) – 39
  • Strawberries – 41
  • Bananas – 51
  • Mango – 51
  • Blueberries – 53
  • Quinoa – 53
  • Oats (rolled) – 55

Medium-GI Foods (56-69)

  • Pineapples – 59
  • Honey – 61
  • Brown rice – 68
  • Popcorn – 65

High-GI Foods (≥ 70)

  • White rice – 73
  • Pretzels – 83
  • Pumpkin (boiled) – 74
  • Potatoes (boiled) – 78

Key Takeaways

Foods with a low GI score raise your blood sugar slowly, unlike high-GI foods that can cause rapid spikes and crashes. People who are managing diabetes or trying to lose weight will benefit most from a diet that has a lot of low-GI foods. But, everyone can benefit from a low-GI diet! It is much better for maintaining your weight and managing blood sugar levels. If you do not have any chronic health problems you are trying to manage, aim for a balanced diet.

Check out our other posts to learn more about healthy eating!

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