Carbohydrates are made up of three components – fibre, starch and sugar. Different foods have different amounts of these three components. Fibre and starch have more complex structures, so take longer to digest, sugars have a simpler structure, so foods with a higher sugar content are digested quickly. For example, white rice has less fibre in it as the bran has been removed, so is quickly digested. Brown rice has a higher fibre content as it still contains the bran so is more complex and slower to digest.
When we eat any type of carbohydrates the pancreas releases a hormone called insulin to move the glucose (sugar) from the blood into the cells. This stops the sugar levels in the blood from getting too high, which is dangerous.
By eating complex carbohydrates such as whole grains, vegetables, beans and fruit; insulin production remains steady and prevents the insulin spikes that can result from eating simple carbohydrates such as sugar, white flour or white rice.
In a high sugar/refined carbohydrate diet, insulin levels will be high, over time the signalling system can start to fail, and the cells won’t uptake the glucose from the blood as well as it should, this is called insulin resistance. Insulin resistance can develop into type 2 diabetes where the body doesn’t respond effectively to insulin.
It is therefore very important to make sure the majority of carbohydrate foods you eat are complex carbohydrates rather than refined carbohydrates.