Afraid of carbs? Don’t be. Not only do you need carbohydrates to perform at your best, new research confirms that eating the right ones can help keep you out of the doctor’s office — and even help prevent weight gain. So instead of looking at a bowl of hearty whole-wheat pasta or brown rice as a big diet no-no, consider it a source of healthy fuel.

Not convinced? Take a close look at the U.S. Department of Agriculture (USDA) 2015–2020 Dietary Guidelines for Americans, which states that 45 to 65 percent of your daily calories should come from carbohydrates. For example, if you eat 2,000 calories a day, 900 to 1,300 calories should come from eating carbohydrates. So rather than being the enemy, carbohydrates are an essential part of a healthy diet, and not banned by any means.

What Exactly Is a Carbohydrate?

There are two types of carbohydrates. Carbs with a simple chemical structure (one or two sugar molecules linked together) are called sugars, according to the National Institutes of Health. Complex carbs consist of starches and fiber. Fiber is unique in that it cannot be digested by the human body.

Both simple and complex carbs break down into glucose (blood sugar) in the body. But because simple carbs are shorter, they generally break down faster, leading to quicker release in the body.

What Role Do Carbohydrates Play in a Healthy Diet?

"Carbohydrate is one of the macronutrients that we need, primarily for energy," explains Sandra Meyerowitz, MPH, RD, owner of Nutrition Works in Louisville, Kentucky. "It's your body's first source of energy — that's what it likes to use."

Why Does the Body Like Carbs So Much?

The glucose from carbs is converted into the energy your brain and muscles need to function, Meyerowitz explains. Fats and protein are also necessary for energy, but they're more of a long-term fuel source, while carbohydrates fulfill the body's most immediate energy needs.

How Many Servings of Carbs Do I Need?

Between 50 and 60 percent of your daily calories should come from carbohydrates, according to Meyerowitz, most of which should be whole grains and other complex carbohydrates.

Is There a Problem With Cutting Back on Carbs?

If you don't get enough carbohydrates, you run the risk of depriving your body of the calories and nutrients it needs, or of replacing healthy carbs with unhealthy fats, Meyerowitz explains. Whole grains, complex carbs, dairy foods, and fruit contain valuable vitamins, minerals, and fiber that your body needs to function at its best. If you cut these foods out of your diet, you may develop a nutrient deficiency or constipation as a result.

Are All Carbs Created Equal?

No. Complex carbohydrates digest slowly. They require more work and take longer for your body to break down, so they deliver energy more steadily and help keep your blood sugar levels more stable, Meyerowitz explains.

Complex carbs are a top source of dietary fiber, and eating a fiber-rich diet cuts the risk of coronary heart disease, stroke, type 2 diabetes, and colorectal cancer by 16 to 24 percent, and is linked with a lower body weight, according to a review published January 10, 2019, in the journal The Lancet. which investigated 40 years of studies.

Simple carbohydrates, or refined carbohydrates, are broken down faster, which can trigger spikes in your blood sugar, and they don't contain as many vitamins, minerals, fiber, and other important phytonutrients as complex carbohydrates do. However, there’s an exception: Simple carbohydrates, including fructose and lactose, are also found naturally in nutritious whole fruits and dairy products. Fruit also contains good-for-you dietary fiber.

Overdoing simple carbs can also pack on pounds, according to a review published in August 2012 in the journal Food and Nutrition Research. The authors looked at 50 studies on diet and weight gain and found that, on average, the more simple carbs a person ate, the more weight they tended to gain.

Which Foods Contain Complex Carbs?

According to the Harvard T. H. Chan School of Public Health, top dietary sources of complex carbs include:

Unprocessed or minimally processed whole grains, like barley, bulgur, buckwheat, quinoa, and oats
Whole-wheat and other whole-grain breads
Brown rice
Whole-wheat pasta
Vegetables
Beans, lentils, and dried peas
Whole-grain cereals, like 100-percent bran

What Are Some Sources of Simple Carbs?

Simple carbs are found in fruit and dairy products, as well as highly processed or refined foods that have been stripped of fiber, including:

White bread
Pastries
Sugary soda and other drinks
Fruit juices
Candy bars

So Is Dessert Forbidden?

Not at all. Occasionally indulging in a sweet treat, like apple pie, ice cream, or other foods containing lots of simple carbohydrates, isn’t a problem. It just that those foods should be the exceptions instead of your everyday carbohydrate selections, Meyerowitz says.

At the same time, you should avoid overloading on complex carbohydrates or making them your primary source of calories. A diet too rich in even complex carbohydrates — or in any food — packs more calories into your body, which eventually leads to weight gain and other health problems.

In other words, as with many good things, moderation is the key to maintaining a strong and healthy body. This was borne out in another study, published August 16, 2018, in The Lancet, which found that the average life expectancy of moderate-carb eaters (someone who got 50 to 55 percent of their calories from carbs) was four years longer than low-carb eaters (those who got less than 40 percent of their calories from carbs). Moderate-carb eaters also lived one year longer than the average high-carb eater.

Carbohydrates: Your Body’s Most Important Source of Fuel