What Are Simple Sugars?

Medically Reviewed by Dany Paul Baby, MD on November 09, 2022
4 min read

As diet fads come and go, it can be hard to keep up with what’s healthy and what’s not. There’s a lot of talk about sugars and carbs, especially as low-carb and keto diets have become trendier. Simple sugars are a type of sugar that many health gurus warn you to avoid, but should you? 

You may have heard that you should try to avoid eating too many simple sugars, but what does that mean? What are simple sugars? Are simple sugars carbohydrates?

To answer both questions: simple sugars are sometimes called simple carbohydrates. Sugars are produced naturally by plants that we eat, including fruits, vegetables, and nuts. Sugar, or carbohydrates, are the most important and accessible source of energy for your body.

Carbohydrates are one of three macronutrients. Macronutrients are the main nutrients your body needs to function properly. The other two macronutrients are fats, which make fatty acids and help your body absorb vitamins A, D, E, and K, and proteins, which help build muscle, tissues, and organs and help regulate hormones.

Sugars or carbohydrates are often described as either “simple” or complex.” Simple sugars are the most basic forms of sugar. They may be monosaccharides, meaning they contain one sugar molecule, or disaccharides, meaning they contain two sugar molecules. Your body absorbs simple sugars into the bloodstream. The rising level of sugar in your blood triggers your pancreas, a hormone gland in your abdomen, to release the hormone insulin. The insulin moves the sugar from your blood into your cells, which then use it as energy.

When you eat foods with simple sugars, your body can absorb and use these sugars for energy quickly. There are a few different types of simple sugars that are a part of the foods we eat every day. Some simple sugar examples include:

  • Fructose: Fructose is found primarily in fruits like apples and pears, but also in some vegetables like onions and red peppers, as well as in honey, sugar beets, and sugarcane.
  • Galactose: Galactose is mainly found in milk as part of the sugar lactose.
  • Glucose: Glucose comes from foods like honey and dried fruits, but your body can also make glucose by breaking down other carbohydrates.
  • Lactose: Lactose is a disaccharide made up of galactose and glucose. It’s found in dairy products.
  • Maltose: Maltose is a disaccharide made up of two glucose molecules. You can find it in some grain products, like bread, as well as molasses and malted beverages like beer.
  • Sucrose: Sucrose is a disaccharide made up of glucose and fructose. It’s the kind of sugar that table sugar is, and can also be found in some root vegetables like beets and carrots.

While simple carbohydrates are either made of one or two molecules, complex carbohydrates are made up of multiple sugar molecules. Your body can only absorb simple sugars, so when you eat foods with complex carbohydrates, those carbohydrates have to be broken down first.

Eating a lot of simple carbohydrates can cause your blood sugar to spike and then crash. When you eat complex carbohydrates, your body absorbs the sugar more slowly because it has to take the time to break the carbohydrates down into simple carbohydrates. This allows your blood sugar to rise more slowly and evenly and helps you avoid a sugar crash.

Examples of complex carbohydrates include:

  • Cellulose: Cellulose is found in the cell walls of plants. You can find it in many fruits, vegetables, and grains. Cellulose is also a good source of fiber.
  • Glycogen: When your body doesn’t use all the glucose that you eat right away, it stores it as glycogen in your liver and muscles for later.
  • Starch: Just as your body stores glucose as glycogen, plants store glucose as starch. Starch can be found in grain foods like flour, pasta, and rice, but also in some vegetables like corn and potatoes.

Some complex carbohydrates, like cellulose, can’t be broken down by the body. These are called fibers. Though your body can’t use these carbohydrates for energy, they’re still important to your health because they regulate the way your body uses sugar. There are two categories of fiber: soluble fiber and insoluble fiber. 

Soluble fiber is fiber that dissolves in water. It can help lower your blood sugar and cholesterol. Foods with soluble fiber include: 

  • Apples 
  • Beans 
  • Blueberries 
  • Chia seeds 
  • Lentils
  • Nuts
  • Oatmeal

Insoluble fibers can’t be dissolved. They help food move through your digestive system. Foods with insoluble fibers include:

  • Almonds
  • Brown rice
  • Fruits with edible skins, like apples and pears
  • Leafy greens
  • Legumes
  • Seeds
  • Walnuts
  • Whole wheat products

Simple sugars aren’t necessarily bad. Many nutritious foods like fruits, vegetables, and dairy products have simple sugars. 

The problem is that a lot of unhealthy foods contain only simple sugars, whereas foods like fruits and vegetables also contain complex carbohydrates and fiber. Simple carbohydrates aren’t as filling, so people want to eat more of them. They can cause your blood sugar to spike and crash, making you feel ill. Because simple carbs raise your blood sugar quickly, they can lead to overall higher levels of blood sugar. Consistent high blood sugar can lead to type 2 diabetes.

One of the best ways to reduce simple sugars in your diet is to look for simple sugar alternatives. You can do this by making changes such as swapping white bread for whole wheat bread or white rice for brown rice. Check nutrition labels. The best foods will be high in dietary fiber and low in added sugar.

You don’t need to cut simple sugars from your diet completely. Trying to do so would deprive you of foods that are high in nutrients your body needs. But making smart choices and choosing complex carbs when possible can help your body feel and be healthier.