The word ‘carbohydrate’ has become increasingly controversial in recent years and because of negative coverage about it in the media, such as being the cause of diabetes, people started omitting carbohydrates from their diets.
Guidelines in Singapore, however, recommend that we obtain our carbohydrates from 5-6 servings of whole grains*, which makes up half our total energy intake.
This article will hopefully help you better understand carbohydrates by detailing its functions, source and health benefits.
*For reference, 1 serving is equivalent to ½ bowl of rice or noodles
Carbohydrates are the primary and most efficient source of energy for humans. As one of the three macronutrients (besides protein and fat), we are encouraged to consume carbohydrates because of the vitamins, minerals and fibre available to us in carbohydrate-containing food sources.
It is crucial to understand that not all carbohydrates are created equally and hence have been classified as ‘complex’ and ‘simple’ or ‘good’ and ‘bad’ respectively. However these terms not only cause confusion but are also inaccurate. ‘Whole’ and ‘refined’ are better descriptions for carbohydrates.
Whole carbohydrates comprise whole grain, fruits and vegetables. It is named as such because the carbohydrate has not gone through any process to strip it of its vitamins, minerals and fibre. Due to the presence of fibre, whole carbohydrates take a longer time to pass through the gastrointestinal tract, keeping you full for a longer period and reducing food cravings, thus potentially helping with weight management. Fibre also helps lower the glycaemic index of the starch hence slowing down the absorption of sugars from the gut, preventing rapid spikes in blood glucose levels which are responsible for post prandial somnolence, commonly referred to as ‘food coma.’
Whole, unrefined carbohydrates tend to have a lower glycaemic index.
In the case of whole grains, the grain still retains its germ and bran layer (the outer layer which gives red and brown rice their colour respectively). These two components of whole grain are where the vitamins (A and E), minerals (selenium and zinc) and fibre content are found, making them more nutritious than their refined counterpart, white rice.
Examples of whole carbohydrates sources include:
Refined carbohydrates refer to grains or any carbohydrate that has gone through any refining process which strips them of their nutrient content.
Milling is a refining process whereby grains such as wheat and rice are stripped of their bran layer and germ, leaving behind its starchy endosperm which is the white rice and white flour which you see on the shelves of your supermarket. This essentially strips the grain of vitamins, minerals and, most importantly, fibre. The same applies to fruit that have been juiced. The juicing process removes most of the fruit’s fibre, leaving behind only the sugary liquid.
Removing the bulk of the carbohydrate’s fibre increases the rate of its absorption through the intestinal wall, consequently causing a spike in blood glucose levels and a subsequent crash, resulting in more cravings and the food coma which we previously mentioned. This phenomenon has a correlation to the incidence of type-two diabetes. As refined carbohydrates empty the gastrointestinal tract relatively faster than whole grains, you would need to consume more of the said refined carbohydrate to feel fuller which results in consuming more calories than needed.
Carbohydrates that fall under this category tend to have a higher glycaemic index.
Examples of refined carbohydrates include:
Here are some simple guidelines which may help you make wise food choices:
The bottom line is to not avoid carbohydrates but instead, make wiser choices by choosing fibre-rich whole grain. Also, avoid sugar in sugar-laden beverages as they contribute to weight gain when not consumed in moderation. Choose fruit instead to satisfy your sugar cravings. By adhering to these, you should be treading the safe zone.
