What are Complex Carbohydrates?

Kris Roudebush

Complex carbohydrates, also called polysaccharides, are organic compounds found in some types of foods. All carbohydrates are made up of sugar molecules; when three or more of these molecules are bound together, it is considered complex. Experts believe that complex molecules are healthier than simple ones because it takes the body longer to break them down. This slow digestion releases sugar into the blood system slowly, creating a consistent level of energy.

Certain vegetables, like peppers,  are considered fibrous carbohydrates, which are categorized as complex.
Certain vegetables, like peppers, are considered fibrous carbohydrates, which are categorized as complex.

Many vegetables, beans, split peas, lentils, and whole grains are complex carbohydrates. Some fruits and vegetables can be considered simple carbohydrates; however, it's important to note that, because of their nutrient-rich content, they can still be part of a healthy diet. Some vegetables, like mushrooms, spinach, onions, broccoli, and peppers, are fibrous carbohydrates, a complex type.

Potatoes are a starchy carbohydrate, which is a complex carbohydrate.
Potatoes are a starchy carbohydrate, which is a complex carbohydrate.

Complex carbohydrates differ from simple carbohydrates in that simple carbohydrates digest or break down into sugar quickly. Sugar that flows into the blood stream quickly causes blood sugar levels to rise and drop rapidly. Simple carbohydrates can be found in items like honey, candy, sodas, and fruit juices. Processed foods are the most common source of simple carbohydrates.

A bowl of oatmeal.
A bowl of oatmeal.

Potatoes are considered a starchy carbohydrate, which is another type of complex carbohydrate. All legumes, which include beans, lentils, and split peas, are complex and fall into the starchy category. So do whole wheat or brown pastas, oatmeal, brown rice, quinoa, barley, and whole grains.

Barley contains complex carbohydrates.
Barley contains complex carbohydrates.

Complex carbohydrates are commonly found raw, dried, or frozen in their whole state. These foods are an important source of fiber, vitamins, and minerals. Any food that's been enriched or bleached is processed and is usually no longer complex. Breads that contain this type of carbohydrate should be heavy for their size, contain no enriched wheat or flour, and should have at least 4 grams of fiber per serving.

The fiber in mushrooms is of the fibrous, complex type.
The fiber in mushrooms is of the fibrous, complex type.

Enriched, bleached, or processed whole wheat does not count as a complex carbohydrate because, during the processing, all the nutrients have usually been stripped. The flour becomes enriched when those nutrients that are considered important are added back in. What's important to know is that not all the nutrients are put back, and the body doesn't process enriched foods the same way as it does unprocessed foods because of those missing nutrients.

Lentils are a type of complex carbohydrate.
Lentils are a type of complex carbohydrate.

Most experts recommend reducing simple carbohydrates and increasing complex ones for a healthy, even source of energy throughout the day. Many people find these nutrients more filling, so consume fewer calories because they feel less hungry. Often, people who reduce simple carbohydrates find that their cravings for sugary snacks will dissipate over time.

Broccoli and other fibrous vegetables are complex carbohydrates.
Broccoli and other fibrous vegetables are complex carbohydrates.

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Discussion Comments


@literally45-- It depends on the kind of pasta you're eating. Regular white pasta is a simple carbohydrate, whole grain brown pasta is a complex carbohydrate.

Basically all the white stuff is made of complex carbohydrates-- rice, white bread, white pasta, biscuits, cookies, cakes, etc. And notice that all of these foods are processed foods (meaning they are no longer in their natural form).

If you love pasta, try switching to a whole grain one. It tastes weird at first but then you get used to it. I personally think that everyone should follow a complex carbohydrate diet for a healthy life.


Is pasta a complex carbohydrate?

I eat pasta almost every day, is that bad?


@highlighter-- You're right. This whole concept is more complicated than we realize. There are a lot of factors involved in how the food we eat affects us.

I'm a diabetic and I am also required to stay away from simple carbohydrates and eat a lot of complex carbohydrates like vegetables and beans. The article said that potatoes are complex carbohydrates, but my doctor told me not to eat potatoes.

So clearly, things are not black and white. Complex carbohydrates are much better than simple carbohydrates but we still can't say that all complex carbohydrates are good.


This info is very detailed and it helped a lot on my report. It's my first time on this site and i think I'm going to use it more often.


@ Highlighter- You are right in your assertion that there are good complex carbohydrates and bad complex carbohydrates. Scientists now rank carbohydrates on their affect on our blood glucose levels. As you stated, carbohydrates are ranked by their GI and GL. The Glycemic index foundation has a great website that they update regularly. The website lists the glycemic index and glycemic load of almost every food you can think of. Just perform a web search for glycemic index.


Some of the best diets recommend eliminating most or all simple carbohydrates. Most importantly, these diets recommend eating carbohydrates with a low glycemic load. There are ongoing studies that are researching the effects of different carbohydrates on diseases like hypertension, heart disease, insulin resistance, and high cholesterol.

Eating a diet high in complex carbohydrates is one of the easiest ways to stay healthy. Some complex carbohydrates should be limited though like potatoes and white bread. As researchers are learning more about complex carbohydrates, the definition of complex carbohydrates is evolving. The glycemic index and glycemic load are important in determining which carbohydrates are good and which carbohydrates are bad.

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