Understanding Glycemic Index: The Best Low GI Foods To Control Diabetes

Written by Rama Manikumar on Tue, 01 August 2023 — Fact checked by Jillian Lai Mei Siew

Key Highlights

  • The glycemic index (GI) measures the impact of foods on blood sugar levels and is crucial for managing diabetes.
  • Low-GI foods are digested slowly, gradually increasing blood sugar, while high-GI foods cause rapid spikes.
  • Incorporating whole grains, fibre, and protein/fat combinations can help lower the GI of meals and stabilise blood sugar levels.
  • Portion control and mindful eating are essential for managing blood sugar, even with low-GI foods.
  • Diabetes management involves a comprehensive approach, including regular exercise, stress management, medical check-ups, and a healthy diet based on the glycemic index.

Managing diabetes can often feel like a meticulous numbers game. From monitoring blood sugar levels to tracking calories, weight, and HbA1c levels, measuring and analysing various parameters is constantly necessary.

However, staying on top of this chronic condition demands unwavering vigilance. Luckily, there’s a tool that can aid in this endeavour by providing a better understanding of the impact that various foods may have on your glucose levels– the glycemic index (GI).

By utilising the GI, you can identify the best foods to control diabetes and make well-informed choices regarding your diet. This will enable you to maintain optimal control over your blood sugar levels.

In this blog, we will dive into how the glycemic index works and how you can leverage it to optimize your journey with diabetes.

Breaking down the Glycemic Index

Many factors determine the glycemic index of food. It varies depending on how many nutrients it contains, how it is cooked, how ripe the fruit or vegetable is, or how much the food has been processed before being packaged and consumed.

Breaking down the Glycemic Index

  • Put simply, the glycemic index is a scale that assigns a numerical value to different foods, which helps you understand how each one will affect your blood glucose levels.
  • For example, foods with a high GI are generally digested rapidly and so will cause an immediate spike in sugar levels.
  • On the other hand, food with low GI is broken down slowly, so your blood sugar will also rise slowly. The GI scale extends from 0 to 100.
  • The higher the food is ranked on the GI scale, the more it affects your blood sugar levels and vice versa.

Hence the glycemic index can help you become more aware of the types of food you consume. In addition to helping with diabetes control, it aids weight loss and reduces cholesterol levels.

A healthy diet should be made up of primarily low-GI foods, such as:

  • Fruits: apples, berries, oranges, lemons, limes
  • Vegetables with low carbohydrates: cauliflower, carrots, spinach, tomatoes
  • Whole grains: quinoa, oats
  • Legumes like black beans, garbanzo beans, chickpeas, and kidney beans

Foods with a high GI include bread, rice, starchy vegetables like potatoes, and sugar-rich beverages like soda, fruit juice, and sports drinks.

Why is the Glycemic Index important for diabetics?

For diabetics, controlling blood sugar levels is vital to maintaining overall health.

High blood sugar can lead to various diabetes-related conditions, including cardiovascular disease, kidney problems, and nerve damage. You can regulate your blood sugar and reduce the risk of complications by substituting high-GI food with low-GI foods into your diet.

Understanding the GI of different foods allows people with diabetes to make informed decisions about their diet.

By opting for meals with a lower GI, you can avoid sudden spikes and crashes in blood sugar levels, helping to maintain a more stable glycemic control throughout the day.

Glycemic Index vs Glycemic Load: What is the difference?

Even though they sound similar, we must differentiate the glycemic index from the glycemic load (GL).

  • The glycemic index doesn’t account for the amount of food you eat.
  • Whereas the glycemic load calculates the number of carbohydrates in a fixed serving of food to tell you how that meal can affect your blood sugar levels.
  • The glycemic load is calculated by considering the speed at which a particular food breaks down and releases sugar in the bloodstream and the amount of sugar it releases per serving. This gives a more realistic estimate. For example, watermelon may have a high glycemic index. However, a serving of watermelon contains very small amounts of carbohydrates, so its glycemic load may be smaller as well, making it an ideal fruit to reduce sugar levels.

Hence, it is advisable to consider both the glycemic index and the glycemic load when choosing foods that lower blood sugar.

Practical tips for using the glycemic index in your diet plan

Practical tips for using the glycemic index in your diet plan

1. Incorporate whole grains into your diet

  • Whole grains, such as brown rice, quinoa, and wheat, have a fibrous coat around the beans, seeds, and cell walls, which act as a barrier.
  • This slows down digestion by reducing the action of digestive enzymes released to break down carbohydrates within the grains.
  • As a result, many whole grains and beans have a lower glycemic index because it releases glucose slowly into the bloodstream.

2. Include fibre in your meals

  • Foods full of fibre, such as fruits, vegetables, legumes, and whole grains, generally have a lower GI.
  • Fibre slows down the digestion process, preventing rapid spikes in blood sugar.

3. Pair carbohydrates with protein or fat

  • When carbohydrate foods are eaten as part of a fibre-rich or protein-rich meal, the GI of the meal changes.
  • It is then measured using an average of individual GI values of the different ingredients used in the meal.
  • Combining carbohydrates with protein or fat can further slow digestion, reducing blood sugar levels impact.

4. Be mindful of portion sizes

  • While the GI is helpful, portion sizes still matter.
  • Even low-GI foods can raise blood sugar if consumed in large quantities.
  • Pay attention to serving sizes and monitor your body's response to different foods to find the right balance.

5. Reduce cooking times if possible

  • The longer you cook vegetables and starches, the more they help the carbohydrates to break down during the cooking process. This makes it simpler and faster for your digestive system to break it down into sugar.
  • Hence, your food could have a higher GI, which causes a steeper glucose spike when cooked longer.
  • Acidic foods like those pickled with vinegar, or lemon juice, tend to have a lower glycemic index.

6. Test and observe:

  • Everyone’s body reacts differently to various foods. Experiment with different foods and track your blood sugar levels to understand how your body responds.
  • Regular monitoring will help you identify patterns and make informed choices.

Additionally, being aware of portion sizes, practicing mindful eating, and avoiding sugary beverages and processed snacks can further support your efforts to control blood sugar levels. Developing healthy habits and gradually changing your diet and lifestyle will yield the best long-term results.

Remember, diabetes management is not just about what you eat but also about maintaining a healthy lifestyle overall. Regular movement and a sustainable exercise regimen, stress control, restful sleep, and periodic medical check-ups are all essential components of managing diabetes effectively.


Living with diabetes does not mean giving up delicious and enjoyable food. With the knowledge and understanding of the glycemic index, you can make informed choices that allow you to savour various ingredients in your meals while keeping your sugar levels within normal levels.

People with diabetes can maintain stable blood sugar levels throughout the day by using the glycemic index to incorporate whole grains, fibre-rich fruits and vegetables, and appropriate protein-fat combinations into their diet.

However, the glycemic index is just one aspect of diabetes management and is not a one-size-fits-all solution. Consultation with a healthcare professional is always advisable for personalised guidance.

By understanding and utilising the glycemic index, individuals with diabetes can take control of their diet and pave the way for better glycemic control, improved overall health, and a higher quality of life. Incorporating the practical tips mentioned earlier can make a substantial difference in maintaining blood sugar levels and decreasing the risk of diabetes-related complications.


Rama Manikumar

Rama is a nutritionist and a lifestyle consultant. Having worked in the health industry for more than 20 years, her expertise in health and well-being brings a fresh and healthy approach to everyday habits- food and lifestyle. She walks the talk and delivers excellent quality nutrition, and helps develop habits that peak health & Well- being. Rama Holds a Batchelor’s degree in Biology; Extended/Specialized degree in Nutrition & Dietetics (Pennsylvania State Univ. USA).

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  1. Sarah

    Wed, 23 August 2023, 6 months ago



      Mon, 28 August 2023, 6 months ago

      Thank you for reading!


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    Our team of experts frequently monitors developments in the health and wellness field, and we update our articles when new information becomes available.

    Current Version

    Aug, 01 2023

    Written By

    Rama Manikumar

    Fact checked By

    Jillian Lai Mei Siew