Mandy Lau, HK BioTek Nutritionist
Glycemic Index (in short term, GI) is a new concept in recent years. More and more countries start to develop interest in the relationship between GI and health. Generally, carbohydrates can be metabolized into glucose molecules. These molecules would be absorbed to bloodstream in guts and leads to the increase in blood glucose level. Different carbohydrates result in different speed of metabolism, as well as the rise in blood glucose level. Glycemic Index reflects the impact of different carbohydrates on blood glucose concentration. The Glycemic Index of glucose is set at 100. Glycemic Index is sub-divided into 3 levels: High GI (70 or higher), Medium GI (56 – 69) and Low GI (55 or lower). The table below lists the Glycemic Index of some common food.
|Low GI (55 or lower)||Medium GI (56 – 69)||High GI (70 or higher)|
|Rice||Black rice, brown rice||Red rice||White rice, Glutinous rice|
|Noodles||Spaghetti and pasta, Chinese vermicelli, Whole egg noodles||Udon, Soba, Rice noodles||Ordinary wheat noodles|
|Bread||Multi-grain Bread, Rye bread||Pita bread, Whole meal bread||White bread, steamed bun|
|Breakfast Cereals||Wholegrain、Oat bran||Wheat、Oatmeal||Cornflake、Cocoa Krispies、Rice Krispies|
|Stem and Root||Sweet Potato、Corn||Beetroot||Potato|
|Sugar||Fructose、Lactose、Sugar Alcohol、Coconut Flower Sugar、Agave Nectar||Sugar Cane、Honey||Glucose、Table Sugar、Maltose|
|Others||Oat Biscuit、Beans||Popcorn、Digestive biscuit||Rice Crackers、Crackers、Pancakes、
Source: Diabetes Hong Kong & Canadian Diabetes Association
Compared with High GI food (e.g. white rice, white bread, corn flake and potato), the rate of metabolism of Low GI food (e.g. brown rice, wheat bread, corn and beans) is slower and results in more stable blood glucose level. Therefore, Low GI food can effectively control blood glucose and lower the risk of type 2 diabetes. Besides, Low GI food enhances the sense of fullness and thus can better control the amount of ingestion and help body weight management.
High GI food, such as rice and noodles, is the prevalent source of carbohydrates in the Chinese society. People are concerned about the risk of having uncontrollably high blood glucose. In fact, by mixing with various Low GI food in each meal, the adverse effects could be minimized. Here are some health tips:
- Increase the proportion of high fiber food in every meal (e.g. fruits and vegetables)
- Replace white rice with other grains (e.g. brown rice, red rice and black rice)
- Consume more soy products
- Avoid eating High GI food alone
- Control the intake amount of meat products and consume according to “Three Lows and One High” principle
- Choose healthier cooking methods (e.g. steam, poach and stew)
You cannot over-consume Low GI food because Low GI food does not necessarily mean low sugar. Besides, you should make a smarter choice of food as high fat food is expected to have low GI. On the whole, you should pay attention to the variety and quantity of food and intake adequate amount of fiber for a better health.