The body needs to use carbohydrates, including sugars, as an energy source. However, food producers also add sugar to many products, which can lead a person’s blood sugar levels to become too high.

Consuming excessive amounts of added sugar can have adverse health effects, so guidelines recommend that people limit their intake.

In this article, we discuss the different types of sugar and explain whether the body needs them to function. We also look at the harmful effects of too much sugar and the recommended amounts to consume.

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Sugar is a form of carbohydrate. The body breaks down all carbohydrates into sugar. There are different types of sugars, which vary in the structure of their molecules.

Monosaccharides comprise just one sugar molecule, making them the simplest form of sugar. They include:

  • glucose
  • galactose, which milk contains
  • fructose, a sugar common in fruits

Disaccharides or polysaccharides are sugars with two or more molecules. These include:

  • sucrose, which is a common form of table sugar
  • lactose, another sugar in milk and dairy products
  • starch

The body breaks down carbohydrates into glucose, which enters the bloodstream and acts as a source of energy.

Some sugars, such as glucose, fructose, and lactose, occur naturally in foods and drinks. Added sugars refer to any sugars in foods that are not naturally occurring, such as sugar in baked goods.

Foods or drinks may also contain highly processed sugars, such as high fructose corn syrup.

Various names for sugars appear on food and drink labels, so people wishing to limit their sugar intake should look out for the following on ingredient lists:

  • raw sugar
  • corn sweetener or syrup
  • high fructose corn syrup
  • brown sugar
  • coconut sugar
  • fruit juice concentrates
  • honey
  • molasses
  • maple syrup
  • invert sugar
  • malt sugar
  • dextrose
  • fructose
  • glucose
  • maltose
  • sucrose
  • lactose
  • syrup

Carbohydrates are fuels that provide the body with energy. The body breaks down foods containing carbohydrates into glucose, which can then enter the bloodstream.

Some glucose is essential for the brain, central nervous system, and red blood cells to function properly.

The body has a natural feedback mechanism by which high glucose levels lead to increased insulin production, and low levels lead to decreased levels of this hormone. The body requires healthy insulin levels to function properly. If there is too little insulin or it no longer functions properly, a person can develop diabetes.

According to the American Heart Association (AHA), the body does not need any added sugar to function healthily.

Naturally occurring sugars come with a variety of nutrients that the body needs to stay healthy. For example, alongside fructose, fruit contains fiber and various vitamins and minerals. Most foods and drinks that contain added sugars, such as chocolate and soda, lack these nutrients.

The Institute of Medicine set the recommended daily carbohydrate intake for adults and children aged 1 year or over at 130 grams (g). They also advise that approximately 45–65% of the calories that adults consume should be carbohydrates.

The body uses sugars and starches from carbohydrates to supply glucose to the brain and provide energy to cells around the body.

Carbohydrates also provide fiber and other nutrients to the body. Eating a variety of fruits, vegetables, and dairy products, among other sources of carbohydrates, can be a healthy way to meet these daily targets.

The Department of Health and Human Services recommend that less than or equal to 10% of daily calories should come from added sugars.

The AHA recommend maximum daily added sugar intakes of less than 36 g, or 9 teaspoons, for males and less than 25 g, or 6 teaspoons, for females. Children aged 2–18 years should have less than 25 g a day.

However, they point out that many people in the United States are consuming too much added sugar. Adults are consuming roughly 77 g of added sugar each day, which is more than three times the recommended daily intake for females. Meanwhile, children are consuming close to 81 g each day.

The AHA highlight that sugar-sweetened beverages are the main source of added sugar in the U.S., with these drinks accounting for 47% of added sugars in a typical diet. Examples of these drinks include:

  • soft drinks
  • fruit drinks and juices
  • sports or energy drinks
  • coffee and tea

Snacks and candies also contribute significantly to sugar intake, accounting for about 31% of the total added sugars in the diet.

Too much sugar can cause serious health problems. It can raise blood glucose levels, potentially causing:

High blood glucose levels can also cause brain problems and increase the risk of dementia, even in people without diabetes.

Excessive sugar intake can also cause:

Sugar is a carbohydrate that occurs naturally in many foods, such as fruits and vegetables. The body breaks down carbohydrates to make glucose, which it requires for energy and healthy functioning.

Added sugars are sugars in foods that are not naturally occurring. The body requires no added sugars to function properly. Many people consume too much sugar from drinks and foods that contain added sugar.

Too much sugar can cause a range of serious health problems, including diabetes, dementia, and obesity.