Do You Know How Sugar Is Metabolized In Your Body?

Metabolism of sugar
Do You Know How Sugar Is Metabolized In Your Body?

In Ayurveda, sweet is one of the six fundamental tastes as it provides nourishment to the body, mind and spirit. Due to this nourishing nature, many people crave the sweet taste. However, eating too much sugar can bring you out of balance and lead to major health issues, including diabetes, heart disease, and liver disease.

In a recent report from 2005-2010 National Health and Nutrition Examination Survey (NHANES) database, it was found that Americans consume about 20 teaspoons of added sugar in the form of sweeteners every day. Between 1970 and 2005, consumption of added sugars in the typical American diet increased by 19% to a total of 64 kilograms per year.


Due to this excessive sugar consumption, many lifestyle diseases have occurred. So, the food industry keeps coming up with different types of sweeteners to deal with this. One where you can have all the sweet taste and not have any side effects, so to speak. But, almost every sweetener, when used excessively causes some or the other side effect. To understand why, we will today look at the various types of basic sugar, how does sugar metabolize in the body and the health effects it might have on you. 

Types of Sugar

There are various types of sugar, chemically speaking.



Usually from sugar cane or sugar beets.

Fructose, maltose and dextrose:

Fruits and starchy plants.



Dairy products.

How are Sucrose, Glucose, And Fructose Sugars Metabolized?

1. Sucrose Metabolism

Sucrose, like all complex sugars, breaks down during digestion into two simple sugars: glucose and fructose. Glucose is transported by insulin to the cells for energy, which, unless burned, gets stored away as fat. (this is where the term- sugar makes you fat).


Sucrose is commonly found in table sugar made from sugarcane or sugar beets. It’s also found in corn and other plants. When you eat sucrose, your body breaks it down into individual molecules of fructose and glucose.

Most commercial sucrose comes from sugar beets and sugar cane. The natural sugar content of the plants is refined to varying degrees to produce granulated, powdered, and brown and specialty sugars, such as demerra and muscovado. Molasses, a byproduct of the refining process, flavors and moistens the darker sugars. Crystals in these sugars range in size and flavor, but the sweetness in each is provided by sucrose.


Chemically, sucrose is a disaccharide, meaning that it is composed of two simple sugars linked together. In the case of sucrose, the two are fructose and glucose. During digestion, the bond between the two is cut and they are absorbed separately by the small intestine.

Sucrose from any source — brown or white, beet or cane — contains 4 calories per gram, as do other sugars. In other words, equal amounts of different sugars provide the same amount of energy to the body. However, some sugars taste sweeter than others, so you don’t need to add as much to get the same level of sweetness.


2. Glucose Metabolism

Glucose is the foundation for the Glycemic Index (GI), which ranks foods on how they affect our blood glucose levels. This index measures how much your blood glucose increases in the two or three hours after eating certain foods. Table sugar, or sucrose, has a GI of 60. Eating low (below 50) on the glycemic index can help you control your blood sugar naturally.

Glucose (also known as dextrose) is the most basic sugar molecule and is the body’s preferred energy source. Most carbohydrates that you eat are processed into glucose, or blood sugar, which your body then immediately uses for energy or stores in muscle or the liver for later use. Your body needs blood sugar levels to stay in a certain range, and the hormone insulin helps regulate these levels.


How Is It Labelled On Food?

When glucose is added to foods, it appears on nutrition labels as glucose, corn sugar or dextrose. And even if it isn’t added to foods, we end up with a lot of it. Many carbohydrates and sugars are ultimately converted by our bodies into glucose.

How Is Glucose Metabolized?

Simple sugars such as fructose and galactose can be converted to glucose by the liver. More complex carbohydrates are digested down to glucose in the gut before being absorbed into the bloodstream.

These include the disaccharide maltose, which is made up of two linked molecules of glucose; maltodextrins or dextrins, which are chains of maltose molecules, and starches, which are chains of maltodextrins.

Effects of Glucose on Health

Once digested, glucose supplies the energy most parts of the body need to work. The amount of glucose in the bloodstream — the blood sugar level — is known to affect athletic performance, brain function, appetite and emotions.

Because this sugar is so critical, levels of available glucose are tightly regulated by hormones such as insulin; errors in this system can lead to disorders such as diabetes. Diabetics inject insulin to keep their blood sugar from going too high and, when necessary, take easily absorbed glucose tablets to quickly bring it back up to healthy levels.

3. Fructose

Fructose is another simple sugar that is naturally found in fruits. It is sweeter than glucose and sucrose. It also serves as a marker in fruit for ripeness and nutritional density. Various processed sweeteners, such as agave nectar and high fructose corn syrup, contain varying amounts of fructose, often giving the sweet taste and calories stripped of the nutrients found in whole fruits.

[pullquote]”The average American gets 10% of their calories from fructose,” says John Bantle, professor of medicine at the University of Minnesota. That’s instead of the 3% they would get just from natural sources such as fruits and vegetables.[/pullquote]

Effects of Fructose on Health

Fructose, which is sweeter than glucose, was once thought to be a possible diabetic-friendly sweetener because it doesn’t cause spikes in blood sugar. The rub was that fructose-sweetened foods tended to have adverse effects on lipids like cholesterol and triglycerides.

In addition to glucose, complex sugars like sucrose or lactose also break down into fructose. People tend to think that fructose is a benign sugar because it is found naturally in fruit. But, despite the name “fructose,” whole fruit actually has a relatively low concentration of fructose compared to processed foods like agave syrup, high-fructose corn syrup, or cane sugar.

Fructose does not raise blood glucose levels immediately the way glucose does, and is therefore considered low on the glycemic index. But that does not mean it’s safe

Fructose travels to the liver where it gets converted to triglycerides—the fats in the blood that are associated with heart disease. Like excess blood glucose, blood triglycerides made from fructose are stored as fat, which increases the size of your fat cells, contributing to weight gain and obesity.

The excess triglycerides created when you eat fructose increase insulin resistance, thereby boosting insulin production to very high levels, which fosters the development of diabetes. Fructose also interferes with the absorption of minerals and impairs the immune system.

In addition, the metabolism of fructose creates free radicals as well as uric acid, which can lead to gout and elevated blood pressure. Another drawback to fructose is that, unlike glucose, it doesn’t curb your appetite when you eat it. In biological terms, fructose doesn’t lower ghrelin, a major appetite-stimulating hormone. Therefore, when you eat a fructose-sweetened food, even though you’re consuming calories, you will continue to feel cravings and can easily end up overeating.

Studies on Fructose Metabolism

Fructose may, indeed, have slightly different metabolic effects on the body. In a 10-week study of 32 obese or overweight people published in May, UC Davis researchers found that those who drank fructose-sweetened beverages (accounting for 25% of their daily energy requirements) had increased levels of blood triglycerides and LDL, or “bad” cholesterol, compared with those who drank similar amounts of a glucose-sweetened beverage. They also had lowered insulin sensitivity, meaning they required more insulin to regulate their blood sugar levels.

Although both groups gained about three pounds during the course of the study, the fructose-drinking group tended to gain that weight in the abdominal cavity, while the glucose group tended to gain fat just below the skin.
Abdominal-cavity fat, elevated triglycerides and lowered insulin sensitivity together place a person at higher risk of developing cardiovascular disease, stroke and type 2 diabetes.

But the story is far from complete. Fructose may have different effects depending on gender, age and body type. For example, the researchers noticed larger effects of fructose on men than women. They are now working on a five-year study to see how sugar consumption affects younger and slimmer subjects.

The findings shouldn’t be interpreted as a recommendation against eating fruit or drinking juice in moderation, says study author Peter Havel, a UC Davis professor in the departments of molecular sciences and nutrition.

Best Way To Consume To Fructose

It’s best to eat fructose in the form of whole fruits and honey where the wholeness of the food prevents overeating—and avoid consumption of concentrated sweeteners such as agave nectar and high-fructose corn syrup, especially in sweetened beverages.