That seems like a stupid question. We all know what sugar is. It is that white stuff in the sugar bowl that we sweeten our coffee and tea with and that we use in baking. We all know it comes from sugar cane. So it is sometimes called “cane sugar” or “table sugar” or just “sugar”. It is also called “sucrose”.
So let’s ask the question in a different way. What is sucrose? Sucrose is made up of two parts: glucose and fructose. Both glucose and fructose are sugars. They are simple sugars, whereas sucrose is a dimer (having two parts). Sucrose is 50% glucose and 50% fructose.
Sucrose is broken down almost immediately after it enters the body. So when we eat sucrose, we are actually eating glucose and fructose.
Glucose is the type of sugar that is present in starch (carbohydrates). Glucose is moderately sweet. Glucose is our fuel. It is digested by every cell in the human body to provide energy for all of life’s processes.
Glucose is necessary for life. It is best if we obtain glucose from complex carbohydrates such as whole grains because, in that form, it is metabolized slowly. (Glucose from sugar is metabolized by the body very quickly. If we eat too much glucose from sugar, it can cause all kinds of health problems, such as diabetes.)
Fructose is the type of sugar that is present in fruit. Fructose is very sweet. It is what makes fruit taste good to us. Eating fructose in the context of whole fruit is good because of the many obvious benefits of fruit. We can do quite well without fructose, but the small amount we consume in whole fruit does us no harm.
Unlike glucose, which is used by every cell in the body, fructose is processed only by the liver
. In the liver, fructose is converted into fat. And the fat produced from fructose ends up in and around the liver and the other vital organs, which causes us to have a fat midsection. Excess fructose in our diet causes even more health problems than dose excess glucose.