The Hidden Sugars – Part 1

There are sugars present in foods you may not be aware of.

We all know that sugar is bad for us.  We are told that sugar should be eaten as a special treat sometimes or avoided altogether.

The reasons for avoiding sugar are clear and well understood by scientists and nutritionists, but not well understood by most people. We just hear that we should limit it or eliminate it from our diet.  We know that it can cause cavities, sugar rushes, hyperactive kids and make us hangry.  Some of us know that it helps make us fat, but don’t know specifically why.

It doesn’t help that when we try to limit sugar it is found everywhere.   Pretty much anything that can be considered processed has some sugar added to it.  Everywhere we look:  anything at the local store, gas station or coffee shop will have added sugar.   Almost everything in a package has sugar added to it.

Why is there sugar in virtually all the things that we eat?  Three reasons: it tastes really good, it is a useful tool for food manufacturers and its cheap.

We may be successful at cutting out all the Frappuccinos, cookies, chocolates, candy bars, hard candies, soda, and other treats from our diet. But we can still be eating lots of sugar without knowing it

These foods are all loaded with carbohydrate that is quickly digested as glucose.

Because sugar is added to so many things, we may be consuming more than we are aware of.  One reason is that we may expect something to not have any sugar added to it, and then later find out that the food is loaded with sugar when we check the nutrition facts.  That’s one way we unexpectedly take in too much sugar.  We may be successful at cutting out all the Frappuccinos, cookies, chocolates, candy bars, hard candies, soda, and other treats. We can eliminate these things and still consume lots of sugar without knowing it.  There are sources in our diet that are not as easily recognizable and many of them are advertised to us as healthy, but our bodies will process them like sugary food.  In fact, most carbohydrates are ultimately processed by the body as sugar and it’s important to understand how this works.  Avoiding sugar in our diet can be very difficult and frustrating, but figuring out how can be very rewarding.

Defining sugar

To explain how we’re eating more sugar than we’re aware of, we’re first going to have to define what sugar is.  The definition I use here is the scientific (and arguably more useful) one.

We typically think of sugar as table sugar, the white crystals that we buy at the grocery store and use to make cookies, cakes and pies or sprinkle into our coffee or tea.  We often hear it called table sugar or sugar but its technical name is sucrose.  Sucrose is just one of many compounds that can be called a “sugar”. To avoid confusion, I will define sugar according to the Wikipedia definition, which is the same definition scientists and nutritionists use:

“Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides (single sugar), include glucosefructose, and galactose.”

More specifically, sucrose is a double sugar or disaccharide (di-“two”, saccharide- “sugar”) made from a molecule of the monosaccharide glucose and one molecule of the monosaccharide fructose.

You may then wonder, what exactly is a sugar?  Sugar is a carbohydrate, a family of natural chemical compounds made by nature from carbon, hydrogen and oxygen.  Carbohydrates are made by plants when they use the energy from the sun via photosynthesis to turn carbon dioxide and water into a form of energy that they can store.

Here are structures of glucose and fructose.  When combined together in a disaccharide, they form sucrose (below).


Unfortunately, the word “sugar” is often used refer to sucrose alone most of the time.  For example, The Sugar Association (an organization that speaks on behalf of the sugar industry) defines sugar as:

“…only to sucrose, a disaccharide, made up of two sugars (glucose and fructose) bound together, that is naturally made by and found in all green plants. Sugar found in the food supply is harvested from sugar beets and sugar cane. ”

This common definition can be misleading and downplays the presence of other sugars in our diet that can be equally problematic.  Glucose is the building block for most carbohydrates and is the most abundant sugar in nature.  It is also the most abundant form of sugar in the diet and is one of the primary fuels for some tissues of the body.  Some tissues and cells (like red blood cells) can only use glucose as an energy source.

Here is the first point that I would like to drive home for all readers:  glucose is a form of sugar and all carbohydrate that is digested ultimately is converted to glucose in the body.

The effects of eating too much glucose are almost as bad as eating too much sucrose, so we should be aware of and limit its consumption.

When you eat too much carbohydrate, you take in too much glucose.  Any glucose that is not immediately used for energy will be used to replenish glycogen, your body’s way of storing carbohydrates.  But when you fill up your glycogen stores, any extra carbohydrate is readily stored as fat.   Also when levels are too high too often, it can cause chronically elevated levels of insulin.  Chronically (i.e. long term) increased levels of insulin can lead to much worse health problems like metabolic syndrome and type 2 diabetes.

Picture of starchy foods like bananas, bread, chickpeas and lentils
There is a lot glucose, i.e. sugar in these “healthy” carbohydrates.

How much glucose intake is too much?  It’s hard to say because everyone has a different metabolism and tolerance for glucose.  Some people can eat higher carbohydrate diets and have no problems with it.  Their body is able to use glucose efficiently for energy and not store any as fat.  Also, they may be able to eat carbohydrate as a significant portion of their food intake and feel full from it.  Others (like me) may consume carbohydrate and get very little satiety (feelings of fullness and not needing to eat more) from it and still feel hungry.

The effects of eating too much glucose are almost as bad as eating too much sucrose, so we should be aware of and limit its consumption.   If we are concerned about limiting sugar in the form of sucrose, then we should also avoid too much sugar in the form of glucose.   We get glucose from carbohydrates in our diet.

Fructose, the other half of sucrose, is also problematic for the body when too much is consumed.  But the body processes fructose differently than glucose and this is where the problems start with high sucrose and fructose consumption in the diet.

I will make this all clearer in part 2.  In part 2, I will cover how the nutrition facts panel on foods don’t always accurately depict how much sugar is really in food, elaborate on how too much glucose in the bloodstream negatively impacts our health and then detail how too much fructose in our diet should be even more concerning.

Leave a Comment