The Health Promotion Board has been exhorting us to cut back on white rice and switching to healthier alternatives, such as brown or basmati rice. This has to do with their glycaemic index, or GI. We unravel the concept here.
The low-GI diet is attractive to those seeking to lose weight without having to give up their beloved carbohydrates. The GI is essentially a tool for ranking carbohydrate-containing foods on how slowly or quickly they are digested and increase glucose levels in their blood after eating.
HOW IT WORKS
The index was designed to help diabetics control their blood sugar levels. It works this way:
When you eat or drink something with carbohydrates, your body breaks the complex sugars and starches down into a simple sugar called glucose. Two main hormones from your pancreas help regulate glucose in your bloodstream. Insulin moves glucose from your blood into your cells while glucagon helps release glucose stored in your liver when your blood glucose is low.
Different types of carbohydrates have properties that affect how quickly your body digests them and how quickly glucose enters into your bloodstream. For example, white bread, white potatoes and biscuits will cause a spike in your blood sugar. If you’re on the GI diet, you would substitute these for carbohydrates that produce a steadier rise in blood sugar.
Diabetics benefit from being on a low GI diet as it reduces the amount of insulin produced by the body during a meal. This results in better blood sugar control, thus lowering their odds of getting complications from diabetes, including problems with the heart, eye and kidney.
In fact, the Health Promotion Board recommends that diabetics choose foods with an eye on GI values to fine-tune meal planning. This diet may also be of use to those who are insulin-resistant or have prediabetes. It also has benefits for those who wish to lose weight, attests Dr Benjamin Loh, a general practitioner at Dr Ben Medical. “Low-GI diets have been shown to promote early satiety, which helps you to feel full during a meal sooner, thus reducing the appetite for more food. In addition, insulin is produced in smaller amounts during the consumption of low-GI food, slowing down the absorption and digestion of food. This combination of factors can reduce weight gain by decreasing fat storage over a period of time,” explains Dr Loh.
Foods on the GI diet are scored on a scale of 0 to 100, based on how much they raise your blood sugar level.
When you’re on the diet, try to eat more foods in the low-GI category and fewer in the high-GI group. Keep in mind that some foods on the higher end of the glycaemic index are still healthy for you, such as sweet potatoes, while some lower-glycaemic foods can pack a lot of calories if you eat too many, like nuts.
Besides portion size, how you combine your food also matters. According to the Health Promotion Board, the impact of a food on blood glucose levels is different when you combine it with other foods. For example, eating a bowl of white rice on its own produces a higher rise in blood sugar levels than when it is eaten together with meat and vegetables. Cooking time is another factor you need to look at, as cooking breaks down the cellular structure of a food, making it easier to digest and raising blood sugar levels.