Are your food choices keeping your blood sugar in check?

When you sit down to enjoy a meal, have you ever wondered how the food you eat affects your blood sugar? The answer lies in something called the glycaemic index (GI), a simple yet powerful tool that can help you understand how different foods impact your body’s glucose levels. From rice to fruits, the GI is a guiding principle that can help you make smarter food choices, whether you’re managing a health condition like diabetes or simply trying to improve your overall wellbeing.

What is the glycaemic index?

The glycaemic index is a ranking system that measures how quickly carbohydrate-containing foods raise your blood sugar levels. Developed in the early 1980s by Canadian researcher David Jenkins, the GI assigns a number to foods based on their effect on blood sugar. The lower the number, the slower the food causes a rise in blood sugar.¹

The GI scale ranges from 0 to 100, with pure glucose having a score of 100. Foods with a high GI (above 70) cause a rapid increase in blood sugar, while those with a low GI (55 or less) result in a slower, more gradual rise.

How does it work in the body?

When you eat food, your body breaks down carbohydrates into glucose, which enters your bloodstream and provides energy. The quicker this process happens, the higher the GI of the food. Fast-digesting carbs, like white bread or sugary drinks, tend to spike blood sugar quickly, leading to energy crashes shortly afterward. On the other hand, foods with a low GI, such as whole grains, vegetables, and legumes, are digested more slowly, providing a steady stream of energy over time.

Why does it matter?

For those with diabetes, the glycaemic index is an important tool in managing blood sugar levels. When the body struggles to produce enough insulin, as is the case with Type 2 diabetes, high blood sugar can become a daily challenge. By choosing low-GI foods, individuals can keep blood sugar levels more stable, reducing the risk of long-term complications like nerve damage, kidney disease, and heart disease.²

But even if you don’t have diabetes, the GI can be beneficial. A balanced diet rich in low-GI foods can help maintain steady energy levels, reduce cravings, and even support weight loss. That’s because low-GI foods tend to keep you feeling fuller for longer, reducing the likelihood of overeating.

DID YOU KNOW?
Foods like watermelon and white potatoes have a surprisingly high glycaemic index. Despite their healthy image, these foods can cause rapid blood sugar spikes!

Low-GI foods: The champions of steady energy

So, what kinds of foods should you aim for if you want to harness the power of the glycaemic index? Let's explore some common low-GI options that are readily available.

	Whole grains Brown rice, wild rice, and black rice are fantastic low-GI options. These grains are widely consumed and retain their fibre and nutrients, helping to slow down digestion and maintain steady blood sugar levels. Instead of opting for refined white rice, consider switching to these whole grains for a healthier, more sustainable energy source.
	Legumes Legumes such as mung beans, lentils, and chickpeas play a prominent role in many local dishes. These foods are high in protein and fibre, making them excellent for providing a slow, consistent release of energy. Mung beans, for example, are used in soups, porridge, and even sweet desserts, offering both nutrition and flavour in every bite.
	Non-starchy vegetables Leafy greens like bok choy, water spinach, and Chinese cabbage are not only nutrient-dense but also have a low GI. Non-starchy vegetables like cucumbers, eggplants, and bell peppers are also widely used in salads, stir-fries, and soups, offering a great way to keep blood sugar levels in check.
	Non-starchy vegetables Nuts such as cashews, almonds, and peanuts, along with seeds like sesame and pumpkin seeds, are staples. These foods are rich in healthy fats, protein, and fibre, making them a great snack option to sustain energy levels throughout the day. Whether sprinkled on salads, added to curries, or simply enjoyed on their own, these nutrient-packed snacks provide long-lasting satisfaction without causing blood sugar spikes.

High-GI foods: a sugar rush you may want to avoid

Now, let’s talk about the other side of the equation. High-GI foods, while they might be tempting in the moment, can often leave you feeling sluggish later on.³ Foods like white bread, pastries, and sugary drinks are processed quickly by your body, resulting in a sharp rise in blood sugar.

While these foods might offer a quick energy boost, that spike is usually followed by a crash, leaving you craving more sugar or caffeine to pick you up again. Over time, consistently high-GI foods can contribute to weight gain, insulin resistance, and even increase the risk of developing diabetes.

DID YOU KNOW?
Eating foods with a low GI can help improve your sleep quality. Since they provide a steady release of energy throughout the day, your body’s natural rhythm stays more balanced, helping you wind down when it’s time for bed.

Balancing the glycaemic index with your lifestyle

Of course, it’s not always about avoiding high-GI foods completely. The glycaemic index is just one piece of the puzzle, and context matters. For example, when you eat a high-GI food, pairing it with a low-GI food can help moderate the impact on your blood sugar. Adding some avocado to your toast or pairing a banana with a handful of nuts can make all the difference.

It’s also important to consider portion sizes. Even low-GI foods can lead to high blood sugar levels if eaten in large quantities. Moderation is key, as is the balance of nutrients – aim for meals that combine carbohydrates, protein, and healthy fats for optimal blood sugar control.

A holistic approach to nutrition

As with all aspects of nutrition, the glycaemic index is just one tool among many. It’s important to think of your overall diet as a complete picture rather than focusing too heavily on any one factor. A varied, colourful diet rich in fruits, vegetables, whole grains, and lean proteins is the foundation of good health, with the glycaemic index serving as a guide to help you choose the best options for your body.

DID YOU KNOW?
The Glycaemic Index (GI) is a system used to rank carbohydrates from 1 to 100, with glucose being the benchmark at 100. Foods with a higher GI are quickly digested and absorbed, causing a rapid spike in blood glucose levels, whereas those with a lower GI cause a slower, more gradual rise. Understanding the GI of foods is important for consumers because it enables them to make better decisions when selecting carbohydrate-rich foods, ultimately helping to manage blood sugar levels more effectively.

Switching to a low glycaemic diet can play a role in managing blood glucose, particularly for individuals with prediabetes or diabetes. Low-GI foods are absorbed more slowly, leading to a gradual increase and decrease in blood sugar levels. However, managing blood glucose also requires considering other factors that affect the GI of the foods, such as the nutrient composition (fibre and fat content) of foods and food preparation methods. While low-GI foods are beneficial for blood glucose control, those high in fat may lead to other health concerns, such as elevated cholesterol levels if consumed in large quantities. Therefore, it is important for consumers to follow a balanced diet based on guidelines such as Singapore's My Healthy Plate and maintain physical activity to support blood glucose regulation.

There are several myths surrounding low-GI foods, with one of the most common being that they can be consumed in unlimited quantities without affecting blood sugar levels. This is false. Even low-GI foods can lead to elevated blood glucose if eaten in large portions. To effectively manage blood sugar, carbohydrate counting is a more reliable method than relying solely on GI values.

Besides low-GI diets, low-carbohydrate, Mediterranean and high-protein diets should be considered in the overall strategy of diabetes management. Some diabetic-specific formulas like NUTREN Diabetes, is a nutritionally balanced, complete formula that can be used as a sole source of nutrition or as a meal replacement to help individuals with diabetes or those aiming to control their blood glucose levels. NUTREN Diabetes is low in GI, with slowly digestible complex carbohydrate and fibre blend to support glucose control, and high in whey protein that stimulates insulin secretion and helps build and repair body tissues. It is lactose and gluten free and with no added sucrose and fructose. NUTREN Diabetes can be part of a healthy meal plan. For example, consuming 1 serving of NUTREN Diabetes as a breakfast meal replacement or half serving of NUTREN Diabetes as a healthy snack between meals.

Zoe Chiang Wan Ling
Medical Affairs Manager & Dietitian
Nestle Health Science Malaysia, Singapore
Facebook: Nestle Health Science Singapore

We hope you found this article insightful and thought-provoking. At Healthful, we are always eager to hear from healthcare professionals, patients, and communities who are making a difference. If you have an interesting story, groundbreaking research, or a unique perspective that you’d like to share, we’d love to connect with you! Please reach out to us at [email protected].

References

Jenkins DJ, Wolever TM, Taylor RH, et al. Glycemic index of foods: a physiological basis for carbohydrate exchange. Am J Clin Nutr. 1981;34(3):362-366.
Asif M. The prevention and control the type-2 diabetes by changing lifestyle and dietary pattern. J Educ Health Promot. 2014;3:1.
Afaghi A, O'Connor H, Chow CM. High-glycemic-index carbohydrate meals shorten sleep onset [published correction appears in Am J Clin Nutr. 2007 Sep;86(3):809]. Am J Clin Nutr. 2007;85(2):426-430.

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Related Topic
Blood Sugar, Food Choices, Glycaemic Index