Carbohydrates: What They Are, Function & Types (2024)

What are carbohydrates?

Carbohydrates (carbs) are a type of macronutrient found in certain foods and drinks. Sugars, starches and fiber are carbohydrates.

Other macronutrients includefat and protein. Your body needs balanced macronutrients to stay healthy.

What do carbohydrates do?

Carbs are your body’s main source of fuel. They give you the energy you need to function. Here’s how the process works:

• When you eat carbs, your digestive system begins to break them down.
• Your bloodstream absorbs the carbs (now called glucose or blood sugar).
• Your body releases insulin, which directs the glucose to your cells for energy.
• If you have extra glucose, your body will store it in your muscles or liver. Once you max out glucose storage in those places, your body converts extra glucose to fat.

The amount of carbs you consume affects your blood sugar. Taking in a lot of carbs can raise blood sugar levels. High blood sugar (hyperglycemia) can put you at risk for diabetes. Some people who don’t consume enough carbs have low blood sugar (hypoglycemia).

Simple carbohydrates vs. complex carbohydrates: What’s the difference?

A food’s chemical structure — and how quickly your body digests it — determines whether a carb is complex or simple. It takes your body longer to break down complex carbs, so they’re less likely to cause spikes in blood sugar. They also contain vitamins, minerals and fiber that your body needs.

Simple carbs, on the other hand, digest quickly. So, they tend to spike your blood sugar. Too many simple carbs can contribute to weight gain. They can also increase your risk of diabetes, heart disease and high cholesterol.

Are simple carbs bad for you?

It might be tempting to think of carbs as “good” or “bad.” Simple carbs aren’t “bad” — but they don’t nourish your body the way complex carbs do. The best rule of thumb is to eat plenty of nutrient-rich complex carbs and eat simple carbs in moderation. Ask your healthcare provider for personalized nutrition recommendations.

What are the different types of carbohydrates?

Foods and drinks can have three types of carbohydrates:

1. Fiber.
2. Starches.
3. Sugars.

Fiber and starches are complex carbs, while sugars are simple carbs. You might also see the words, “total carbohydrates” on a food’s nutrient label. This refers to a combination of all three carb types.

Fiber

Plant-based foods — like fruits, vegetables and whole-grain products — containfiber. Animal products, including dairy products and meats, have no fiber.

Fiber is a complex healthy carbohydrate with two types — soluble and insoluble. Your body can’t break down fiber well, but soluble fiber can dissolve in water whereas insoluble fiber can’t. Corn is an example of insoluble fiber. Soluble and insoluble fiber pass through the intestines, stimulating and aiding digestion. Fiber also regulates blood sugar, lowerscholesteroland keeps you feeling full longer.

Experts recommend that adults consume 25 to 30 grams (g) of fiber every day. Most people get half that amount.

High-fiber foods include:

• Beans and legumes, like black beans, chickpeas, lentils, lima beans, peanuts and pinto beans.
• Fruits, especially those with edible skins (apples and peaches) or seeds (berries).
• Nuts and seeds, including almonds, walnuts, pumpkin seeds and sunflower seeds.
• Whole-grain products, like brown rice, oatmeal, quinoa, cereal and whole-wheat bread and pasta.
• Vegetables, like corn, broccoli, brussels sprouts and squash.

Starches

Starches are complex carbohydrates that also give your body vitamins and minerals (micronutrients). It takes your body longer to break down complex carbohydrates. As a result, blood sugar levels remain stable, and fullness lasts longer. Many starches (but not all) fit this category.

You can find starchy carbohydrates in:

• Beans and legumes, like black beans, chickpeas, lentils, lima beans and kidney beans.
• Fruits, like apples, berries and melons.
• Whole-grain products, like brown rice, oatmeal and whole-wheat bread and pasta.
• Vegetables, like corn, peas and potatoes.

Sugars

Sugars are a type of simple carbohydrate. Your body breaks down simple carbohydrates quickly. As a result, blood sugar levels rise — and then drop — quickly. After eating sugary foods, you may notice a burst of energy, followed by tiredness.

There are two types of sugars:

• Naturally occurring sugars, like those found in milk and fresh fruits.
• Added sugars, like those found in sweets, canned fruit, juice and soda. Sweets include things like cookies, candy bars and ice cream.

Sugar goes by many names. On food labels, you may see sugar listed as:

• Agave nectar.
• Cane syrup or corn syrup.
• Dextrose, fructose or sucrose.
• Honey.
• Molasses.
• Sugar.

Limiting sugar is essential to keep your blood sugar levels in the healthy range. Plus, sugary foods and drinks are often higher in calories which can contribute to weight gain. Limit refined foods and foods that contain added sugar, like white flour, desserts, candy, juices, fruit drinks, soda pop and sweetened beverages. The American Heart Association recommends:

• No more than 25 g (6 teaspoons or 100 calories) per day of added sugar for most people assigned female at birth (AFAB).
• No more than 36 g (9 teaspoons or 150 calories) per day of added sugar for most people assigned male at birth (AMAB).

What’s the recommended daily amount of carbohydrates?

There isn’t a set amount of recommended daily carbs. Your age, sex, medical conditions, activity level and weight goals all affect the amount that’s right for you.Counting carbshelps some people with diabetes manage their blood sugar.

For most people, the U.S. Department of Agriculture (USDA) recommends a healthy plate approach. You should fill:

• Half your plate with fruits and vegetables.
• One-quarter of your plate with whole grains.
• One-quarter of your plate with protein (meat, fish, beans, eggs or dairy).

Is a low- or no-carb meal plan healthy?

Some people cut their carb intake to promote weight loss. And some healthcare providers recommend theketo diet for epilepsy and other medical conditions.

These restrictions can be hard to follow over a long time. Some carb-restrictive meal plans include large amounts of animal fat and oils. These foods can increase your risk of heart disease. Talk to your healthcare provider before cutting carbs or making major changes to the foods you eat.

A note from Cleveland Clinic

Your body needs carbohydrates to stay healthy and work properly. The secret is to choose complex carbs more often than simple carbs. Your best bet is to choose mostly nutrient-dense foods with fiber, vitamins and minerals. Limit foods that have added sugars. Your healthcare provider can help determine the right amount of carbs for your needs.