05/08/2025
Understanding Diabetes and Blood Sugar in Everyday Life
Diabetes mellitus is a disease that happens when the level of sugar in your blood becomes too high. The sugar, called glucose, gives your body energy to function. Your brain depends on glucose to stay alert and in control of your body.
When you eat food that contains carbohydrates like rice, bread, or sweet potatoes, your blood sugar naturally rises. Your body then releases a hormone called insulin, from the pancreas. Insulin helps moves glucose from your blood into your body’s cells, where it is used as energy or stored for later use. This helps lower your blood sugar back to a safe level.
In a healthy body, the amount of glucose in your blood is tightly controlled and usually stays between 4.2 and 6.2 mmol/L. If your blood sugar gets too low, such as when you fast for a long time, your body can bring it back up. It does this by taking sugar stored in the liver, called glycogen, and convert it back into glucose. If the stored sugar runs out, your body has a backup plan. It can create new glucose from lactic acid, fatty acids and amino acids in your body. This is called gluconeogenesis. So, even when you’re not eating, your body works hard to keep your blood sugar level just right.
One of the main sources of sugar in the blood is the carbohydrates we eat every day. These carbohydrates are found in food such as cassava, yam, bananas, rice, noodles, bread, flour, and sugar. Carbohydrates come in different forms. Some are simple and can be absorbed directly into your blood, like glucose and fructose. Others are more complex, like starch, and must be broken down into glucose before they can be used.
Digestion starts in the mouth. As you chew, enzymes in your saliva begin breaking down starch into smaller fragments. When the food reaches the small intestine, other enzymes break the starch down further into single sugar molecules like glucose, which is then absorbed into your blood. Some starch is not digested in the small intestine. Instead, it moves into the large intestine, where it is broken down by healthy gut bacteria. This produces helpful substances like short-chain fatty acids that are good for your health.
Now, the speed at which the sugar enters your blood is important, especially for people with diabetes. Some foods cause a fast rise in blood sugar, while others raise it slowly. This speed is measured using something called the Glycaemic Index (GI). Foods with a high GI are quickly digested and absorbed, leading to a fast rise in blood sugar. Foods with a low GI break down slowly, giving your body time to absorb sugar bit by bit.
The GI of food depends on the type of starch, how the food is cooked, what you eat it with, and even whether it’s hot or cold. For example, boiling food like sweet potatoes or cassava usually results in a lower GI compared to frying, which can make the starch break down faster and raise the GI. Bread or Rice, are softer, making it easier to digest quickly and leading to a higher blood sugar spike.
On the other hand, if you boil starchy foods and then cool them before eating, like cold boiled potatoes the starch changes form and becomes more resistant to digestion. This can actually lower the GI, which is better for blood sugar control.
Adding vegetables to your meals also helps slow down the digestion of starch. Vegetables contain fibre, which slows how quickly food moves through your stomach and intestines. This delay reduces how fast sugar gets into your blood. For example, if you eat cassava with leafy greens or taro with slippery cabbage, the fibre in the vegetables helps reduce the glycaemic impact of the starchy food.
Using coconut milk in cooking, such as in local dishes like cassava pudding or taro in coconut cream, can also lower the GI of the food. Coconut milk contains healthy fats, and fat naturally slows digestion. When digestion slows down, sugar is released into the blood more gradually. This makes meals with coconut milk friendlier to people with diabetes, compared to eating dry or plain starchy foods by themselves.
Fruits also contain natural sugars, and they have their own glycaemic index. Some fruits, especially ripe and soft ones like ripe bananas, pawpaw, or watermelon, have a higher GI and cause a faster rise in blood sugar. Less ripe or more fibrous fruits like green bananas, guava, or apples have a lower GI and are more slowly absorbed. Fruits also contain fibre and water, which help reduce how quickly sugar is absorbed.
It is important to understand that different types of sugars have different effects on your blood sugar. Glucose, which is the body’s main sugar, has a glycaemic index of 100. It is absorbed very quickly and causes a rapid increase in blood sugar. Fructose, which is found in fruits and honey, has a much lower glycaemic index, around 15 to 25, because it is absorbed more slowly and needs to be converted by the liver before it can be used as energy. This means fructose does not spike blood sugar as quickly as glucose. However, eating too much fructose over time (especially in processed food or sweetened drinks) can lead to fat buildup in the liver and other health problems.
Glycaemic load is another helpful idea. While the glycaemic index tells us how fast sugar enters the blood, glycaemic load tells us how much sugar will enter the blood from the actual amount of food you eat. For example, watermelon has a high GI, but the amount of sugar in a small slice is low, so its glycaemic load is not very high. That means you can still enjoy it in moderation without a major effect on your blood sugar.
For people living with diabetes, or anyone trying to stay healthy, it is important to choose foods that raise blood sugar slowly and steadily. Traditional foods like boiled green bananas, taro, yam, and cassava eaten with vegetables or coconut milk are better choices than processed snacks, white bread, or sugary drinks. Knowing how your food is prepared, whether it’s baked, boiled, fried, or eaten with vegetables, can help you manage your blood sugar and avoid complications from diabetes.
Understanding the glycaemic index and how it changes with cooking and food combinations gives you the power to make better decisions every day. It is not just about what you eat, but how you prepare and combine your food. This knowledge is a useful tool we have to prevent and control diabetes in our communities and protect the health of our families for generations to come.