Living with diabetes series

What is the Glycemic Index?

How does it affect the blood sugar levels when you have diabetes?

Photo by Sara Dubler on Unsplash

I am sure you’ve heard of low GI and high GI foods in relation to healthy eating and especially with reference to diabetes. The phrase glycemic index gets thrown around a lot and until I was diagnosed with type 2 diabetes, I didn’t really dig deep. And when I did, it made a lot of sense to me.

Let’s talk about the Glycemic Index today and why people with diabetes and those interested in healthy weight management should pay attention to it.

What is the Glycemic Index?

The Glycemic Index is a ranking system — for carbohydrate-containing foods based on the effect of a specific food we eat on our blood glucose. This ranges from a scale of 0 to 100 and the reference point is pure glucose which has a GI of 100. The higher the food’s GI, the more rapid the rise in blood sugar.


What affects the glycemic index of a food?

We can go by the standard rule that the more you cook and process a food, the higher its GI, but there are exceptions. Fat and fiber lower the food’s GI. Here are some common examples of what affects a food’s GI:

  • The riper the fruit or vegetable, the higher the GI
  • Compared to whole fruits, juices have a higher GI thanks to the processing.
  • Compared to a whole baked potato, mashed potato has a higher GI
  • GI also depends on the cooking method and time

GI values may show the type of carbohydrates in the food, but it is important to still worry about portion control especially because healthy weight is one of the criteria for managing blood glucose.

The GI of a food can vary depending on other factors

GI depends on how you eat a food item; whether you eat only that food or combine it with other foods. So, if you eat a high GI food, combine it with a low GI food to balance its effect on your blood glucose levels.

Ironically a number of nutritious foods are high GI compared to low nutrition foods which are low GI. Oatmeal, which is healthy, has a higher GI than chocolate. So can you choose chocolate? Hmm, no! Point is, there is more to eating healthy than only considering the GI even though GI is a major aspect of blood sugar control.

So should you count carbs or go with GI?

As I said earlier there is no standard one-size-fits-all diabetes diet. Meal plans must be customized to your personal needs and lifestyle so that you achieve your blood sugar, cholesterol, and triglyceride level goals even as you maintain your blood pressure and a healthy weight.

GI helps you fine-tune your blood glucose management

Our bodies work best when the blood sugar is stable. When blood sugar levels drop too low, we feel lethargic and feel hungrier. If it shoots up our pancreas goes on overdrive to release more insulin. The insulin brings blood sugar back down by converting the extra sugar into stored fat. So as your blood sugar rapidly increases, the greater the production of insulin, resulting in the risk of your blood sugar becoming too low. Kind of a vicious cycle.


So when you eat foods that cause a rapid glycemic response (when you eat a high GI food), there’s a quick rise in energy and your mood with a rise in blood sugar. But this is quickly followed by the sequence of more fat storage, lethargy, and hunger.

It is bad enough about the increased fat storage, but in the case of diabetics, this is a bigger problem. Because their insulin production or processing is impaired, their blood sugar may rise too high resulting in a number of other issues.

You should therefore care about the glycemic index as you can use it to minimize insulin-related problems — by recognizing and avoiding foods that are likely to mess up your blood sugar levels.

This brings us to the question:

Should we avoid all high GI foods?

Not if you are not diabetic. Sometimes you may need a quick blood sugar and insulin high, especially after extensive work out as insulin helps push glucose into the muscles where it has the job of repairing tissues. This is why athletes use sports drinks — high GI — as soon as they exercise to recover.

Another thing to remember is — glycemic index is not solely responsible for raising blood sugar. Portion control matters. You’ll come across something called “glycemic load” which is the glycemic index plus the amount of food consumed.

Glycemic load is the glycemic index plus the amount of food consumed

For instance, if you eat a high GI bit of candy, your body’s response will be low, simply because it depends on the type as well as the amount of carbohydrate. This is called the glycemic load. So you can control your body’s glycemic response by paying attention to low GI foods and curbing your carbohydrate consumption.

To summarize

Our body needs energy to be active. This comes from carbs that are broken down into glucose and absorbed by the blood. But too much or too little can cause problems.

Also, there are two types of carbohydrates: simple and complex.

Simple carbs such as sugar, honey, jaggery, maple syrup should be minimized and complex such as whole grains, legumes, starchy vegetables must be maximized.

So, choose low GI foods to control blood sugar and blood cholesterol levels, control your appetite and reduce your risk for heart disease and type 2 diabetes.

In general, a healthy diet that has whole grains, fresh fruits and vegetables, nuts, legumes, and dairy products in the right quantities can ensure low GI for diabetics.

High fiber foods are a must, while minimizing processed foods. Sugar, soft drinks, potatoes, bread made of white flour, sweet desserts, and candy bars must be avoided.

A food’s GI won't change with serving size, but overeating a specific food can raise your blood sugar and take some time to become normal.

How to go low GI?

By making healthy choices. Here are some tips:

  • Swap high GI foods for low GI foods
  • Eat one serving of low GI carbohydrate food with each meal
  • Choose low GI snacks
  • Practice portion control.

The following plate is recommended as a reference:


Here are some tips to construct your healthy low-GI plate

  • Fill half the plate with vegetables, salads, one quarter with low GI carbs, and the remaining quarter with lean protein
  • Eat your colors and get at least five servings of vegetables every day.
  • For protein, consider lean meat, skinless chicken, fish, seafood, eggs, milk, yogurt, cheese, legumes, and tofu
  • Low GI carbs include slow-cooked pasta, low GI white rice, quinoa
  • Go for whole-grain bread
  • Rather than processed breakfast cereals, choose natural muesli, porridge oats, or cereals that have the GI symbol
  • Include lots of legumes like beans lentils, chickpeas at least 2–3 a week. I eat them every day as I am a vegetarian
  • No need to be sad about cutting out high GI foods. Combine them with low GI foods to balance them. Using vinegar on your salads, yogurt with your cereals, and lemon juice on your veg can lower the GI
  • Snack smart by going for fresh fruit, nuts, and yogurt. This means refined flour items like cookies, biscuits, and crackers are preferably avoided
  • Make water your best friend. When you are tempted to grab a fizzy sugary drink, bypass it and choose water. And drink at least eight glasses of water every day, unless otherwise advised by your doctor

Here is an exhaustive downloadable resource that lists the GI of various foods for your ready reference.

In a majority of people diagnosed with diabetes, the main problem is the lack of diabetes education. The Living with Type-2 Diabetes series will cover various aspects of the condition with tips and suggestions to manage it better.

In this series so far:

The ABCs of Diabetes
Blood Pressure and Living with Diabetes
Does Dessert Have a Place in the Diabetes Diet
The Cholesterol-Diabetes Connection
The Diabetes Diet and Living with Type 2 Diabetes
Let’s Bust 10 Diabetes Diet Myths!
Why is Exercise Important in Diabetes?
Why Footcare Plays A Crucial Role in Managing Diabetes

Disclaimer: The information in this post is purely for educational purposes only and does not substitute medical advice, diagnosis, or treatment. Always consult your physician for medical advice, diagnosis, and treatment.

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Writing about Self Improvement, Mindfulness, Meditation, Parenting, Health, Travel, Life, Books. Showing my diabetes who’s boss. Visit: