Carbohydrates — fiber, starches and sugars — are essential food nutrients that your body turns into glucose to give you the energy to function. Complex carbs in fruits, vegetables and whole-grain products are less likely to spike blood sugar than simple carbs (sugars). Low-carb diets like keto can be high in fats.

What are carbohydrates?

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

Other macronutrients include fat and protein. Your body needs these macronutrients to stay healthy.


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How does the body process carbohydrates?

Your digestive system breaks down carbs into glucose or blood sugar. Your bloodstream absorbs glucose and uses it as energy to fuel your body.

The amount of carbs you consume affects 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).

What are total carbohydrates?

Foods and drinks can have three types of carbohydrates: starches, sugars and fiber. The words “total carbohydrates” on a food’s nutrient label refers to a combination of all three types.


What’s the difference between simple and complex carbohydrates?

A food’s chemical structure, and how quickly your body digests it, determine whether the food is a complex or simple carb. Complex carbs are less likely to cause spikes in blood sugar. They also contain vitamins, minerals and fiber that your body needs. (You may be familiar with the term “good carbohydrates," but it may be best to think of them as healthy carbohydrates. )

Too many simple carbs can contribute to weight gain. They can also increase your risk of diabetes, heart disease and high cholesterol.

What are starches?

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

You can find starchy carbohydrates in:

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

What is fiber?

Plant-based foods, such as fruits, vegetables and whole-grain products, contain fiber. Animal products, including dairy products and meats, have no fiber.

Fiber is a complex healthy carbohydrate. Your body can’t break down fiber. Most of it passes through the intestines, stimulating and aiding digestion. Fiber also regulates blood sugar, lowers cholesterol and keeps you feeling full longer.

Experts recommend that adults consume 25 to 30 grams of fiber every day. Most of us get half that amount.

High-fiber foods include:

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

What are 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 consuming sugary foods, you may notice a burst of energy, followed by feeling tired.

There are two types of sugars:

  • Naturally occurring sugars, such as those found in milk and fresh fruits.
  • Added sugars, such as those found in sweets, canned fruit, juice and soda. Sweets include things like bakery, candy bars and ice cream. Choose fruit canned in juice over other varieties. Note that sugar-free soda is available.

Your body processes all sugars the same. It can’t tell the difference between natural and added sugars. But along with energy, foods with natural sugars provide vitamins, minerals and sometimes fiber.

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

  • No more than 25g (6 teaspoons or 100 calories) per day of added sugar for most women.
  • No more than 36g (9 teaspoons or 150 calories) per day of added sugar for most men.

What is the recommended daily amount (RDA) for carbohydrates?

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

For most people, the U.S. Department of Agriculture (USDA) recommends a healthy plate or MyPlate 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 diet healthy?

Some people cut their carb intake to promote weight loss. Popular low-carb diets include the Atkins diet and the ketogenic (keto) diet. Some healthcare providers recommend the keto diet for epilepsy and other medical conditions.

Strict dietary restrictions can be hard to follow over a long time. Some carb-restrictive diets include large amounts of animal fat and oils. These foods can increase your risk of heart disease. Experts still aren’t sure if a low- or no-carb diet is healthy. Talk to your healthcare provider before trying a low- or no-carb diet.

A note from Cleveland Clinic

You may have been thinking of carbohydrates as either "good" or "bad." As with all foods, the secret with carbohydrates is to make smart decisions and limit the ones that aren’t as healthy for you. Your best bet is to choose nutrient-dense carbs that have fiber, vitamins and minerals. Eat foods that have added sugars in moderation. Your healthcare provider can help determine the right amount of carbs for your needs.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 02/08/2021.

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