Glycaemic Index

Have you noticed that more and more food products labelled with “Low GI” on packaging are available in the supermarket?

What is GI?Bread

Carbohydrates are the body’s preferred fuel source. The glycaemic index (GI) ranks carbohydrates in foods on a scale from 1 to 100 based on how quickly and how much they raise blood glucose after eating. These are the three classifications for GI:

  • Low : 55 or less
  • Moderate : 56 – 69
  • High : 70+GI

Carbohydrates with a high GI value, e.g. simple sugar, break down quickly during digestion and produce a large rapid rise and fall in the level of blood glucose. However, food with a low GI value such as whole grains are more slowly digested and absorbed, causing a lower and slower rise in blood glucose.

Is low GI food better?

Some evidence has shown that the low-GI diet may result in weight loss, reduce blood sugar levels and lower the risks of heart disease and type 2 diabetes. However, the results are not conclusive yet. Nonetheless, you are still encouraged to choose low or moderate GI foods in view of their potential benefits. It is not necessary to avoid foods with a high GI value totally as many of them have high nutritional values as well.

What are the GI value of my food?

Generally, the less processed or cooked a food is, the more likely it is to have a low-GI score, The type of sugar in a food also affects GI value. The table below groups common carbohydrate foods according to their GI value.


Low GI

Moderate GI

High GI

Starchy staples Wholemeal pasta, rolled oats Brown rice, basmati rice, wholemeal bread, quick oats, pasta White rice, white bread, noodles, instant oats
Whole fruit Apple, orange, kiwi, berry, mango Banana, grape, papaya


Melon, pineapple


Vegetables Green leafy vegetable, tomato, carrot, corn Yam Potato, pumpkin, sweet potato
Beans and nuts Lentil, almond, peanut
Dairy products Low-fat milk/yoghurt
Beverages Fruit juice Soft drink


Can I eat as much low GI food as possible?

Glycemic Index gives us an idea about how fast our body converts the carbohydrates but says nothing about how much we are actually consuming. The amount of the carbohydrate intake will also affect your blood glucose levels. Portion sizes are still important for managing blood glucose level and preventing unnecessary weight gain. In summary, a healthy, balanced and moderate diet is still the key to maintain health.


If you have any general inquiries about diet and nutrition, you can contact us at our

Call-A-Dietitian hotline 983-22-983 !

Brought to you by Zhang Liyuan, Dietitian of Khoo Teck Puat Hospital

Follow us on Instagram @ktph.dietitians for more nutritional goodness!




American Diabetes Association, Lifestyle Management: Standards of Medical Care in Diabetes—2018, viewed 29 July 2019,

Glycemic Index Foundation, What is GI? Viewed 29 July 2019,

Health Promotion Board, The GI values of common foods, viewed 29 July 2019,


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