Glycemic Index 101
Your guide to choosing the right carb sources using the glycemic index
Do you relate to this kid?
If you’re a hardcore carb-lover, it’s time to think about whether your go-to carb-loaded foods are actually good for you.
Just like you’d consider a movie’s reviews before watching it, the glycemic index is a “rating” for foods that have carbohydrates.
When you eat foods that contain carbohydrates, your blood glucose levels rise to break down these nutrients. The glycemic index of a food, which is a numerical value, tells you how fast your blood glucose levels will rise:
- A high glycemic index means that the carbs in that food item are digested faster. Your blood glucose levels rise more rapidly as a result, causing the pancreas to release more insulin. Your blood glucose levels then quickly fall. This makes you feel hungry much sooner and causes cravings.
- A low glycemic index means that the carbs in that food item are digested slower. Thus, your blood glucose levels rise at slower rates.
The glycemic index is a number from 1 to 100 and denotes how fast a food item raises your blood glucose levels compared to pure glucose.
For example, if a food item has a glycemic index of 61, the rise in blood sugar levels will be 61% of that by pure glucose.
Should you care about the glycemic index of the foods you eat?
This depends on your dietary goals.
Some people use the glycemic index as a tool to help monitor their carbohydrate intake. Foods with low glycemic indices help prevent drastic rises in your blood glucose levels, which might help in weight loss. The glycemic index is also useful for people with diabetes, as they need to keep their blood glucose levels in control.
So, knowing the glycemic indices of the foods you eat might be useful for
- weight loss and and/or weight maintenance,
- preparing and eating healthier meals, and
- diabetes management.
What food items have low and high glycemic indices?
Here’s the general rule: processed foods usually have higher glycemic indices, while those high in fat and fibre have lower glycemic indices. Below are the categories according to Mayo Clinic:
- High glycemic index — 70 or higher (potatoes, white wheat bread, white rice, cornflakes, rice milk, rice crackers)
- Medium glycemic index — 56 to 69 (chapatti, wheat roti, raw pineapple, boiled sweet potatoes, soft drinks/sodas, popcorn, honey)
- Low glycemic index — 1 to 55 (green vegetables, barley, most fruits, full fat and skim milk, chickpeas, kidney beans, lentils, soya beans, fruit yoghurt)
Should you rely on the glycemic index for healthier dietary choices?
The answer is no.
The glycemic index does not tell the entire story regarding the nutritional value of a food item.
For example, watermelons have a glycemic index of 80, which is high. But this does not mean that watermelons are carb-loaded enemies. In fact, watermelons give your body fewer carbohydrates per serving. Full fat milk might have a low glycemic index, but this does not make its consumption ideal for weight loss.
So, consider the glycemic index merely as a tool for eating healthier. It can help you choose the healthier carbohydrate sources and monitor your carbohydrate intake. If you think being vigilant about the glycemic indices of foods you eat will help you in your health goals, it’s best to talk to your doctor before making drastic changes.
Like you would not rubbish a movie based on one bad review, don’t overlook the importance of other nutrients while choosing foods based on their glycemic indices!
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