What Is a Complex Carbohydrate?

By: Lainey Younkin, M.S., R.D.

Carbs can get a bad rap. But not all carbs are created equally. We explain why complex carbs are better than others and how to incorporate them into your diet.

Recipe to Try: Creamy Fettuccine with Brussels Sprouts & Mushrooms

Carbohydrates have had their ups and downs lately. And carbs can be complicated. When you hear, "carbohydrates," you may envision white bread, rice and pasta, and think these are foods to limit or avoid. But have you heard the recent buzz about complex carbohydrates and how they can be part of a healthy diet?

Everyone needs carbohydrates; they're your body's preferred source of energy. Digested faster than protein and fat, they give your brain and muscles needed fuel so you can think and move. How many carbohydrates you need in a day depends on your individual needs. According to the Dietary Guidelines, carbohydrates should make up 45-65 percent of your daily calories. For example, if you eat 2,000 calories a day, about 900-1,300 calories should come from eating carbohydrates. This translates to about 225-325 grams of carbohydrates per day. And most of those carbs should come from healthy complex carbohydrate sources.

Related: What Does a Healthy Serving of Carbs Look Like?

What's the Difference between Simple and Complex Carbohydrates?

Honey

Simple carbohydrates (aka simple sugars) are broken down quickly by your body—they have just one or two sugar molecules linked together. Honey (fructose and glucose), table sugar (sucrose) and milk (lactose) all contain simple carbohydrates.

Complex carbohydrates have more nutrients and take longer for your body to digest, so they help fill you up and don't cause the same swings in blood sugars as simple carbs. "Complex carbohydrates are larger molecules than simple carbohydrates," says Molly Cleary, M.S., R.D., a registered dietitian in New York City. "This means it takes our body longer to digest and absorb them." Grains, beans, fruits and vegetables (yes, even potatoes) all contain complex carbohydrates. Many carb foods have a mix of carbohydrates; for example, fruit contains natural fruit sugar (fructose, a simple carb) as well as dietary fiber (also a type of carb). The most healthful carbohydrates—unrefined plant foods that are low in added sugars and high in fiber— are what we tend to call "complex carbohydrates" and what we could all use more of in our diet.

Apple-Cinnamon Quinoa Bowl

Recipe to Try: Apple-Cinnamon Quinoa Bowl

Why Are Complex Carbohydrates Better Than Simple Carbohydrates?

Sweet Potato Carbonara with Spinach & Mushooms

Recipe to Try: Sweet Potato Carbonara with Spinach & Mushooms

1. Complex carbs keep you full longer and keep blood sugar levels steady.

Foods that are mostly made up of simple carbohydrates—candy, pastries, soda—provide an instant source of energy, but they are digested quickly and spike your blood sugar. This leads to the post-sugar crash you may be familiar with, and feeling hungry again soon after. Complex carbohydrates take longer to break down since their molecular structure is larger. The best ones also have plenty of fiber, which moves slowly through the digestive tract. "Complex carbs digest more slowly and help us to feel more satiated and fuller for longer—so it can help with portion and eating control," says Isabel Smith, M.S., R.D., C.D.N., registered dietitian and founder of Isabel Smith Nutrition, Inc.

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2. Complex carbs have more nutrients.

"In addition [to regulating blood sugar], complex carbohydrates often also contain fiber, vitamins, minerals and antioxidants that simple carbohydrates do not," says Cleary. For example, a sweet potato is chock-full of vitamin A, fiber and antioxidants, whereas simple carbohydrates provide sugar but without the healthful nutrients.

3. Complex carbs are good for your heart and might help you lose weight.

Foods rich in soluble fiber—the kind found in complex carbohydrates like apples and oatmeal—can help lower your LDL or "bad" cholesterol. Eating 25-35 grams of fiber per day can help with not only losing weight but also keeping it off long-term. The average American only eats about 15 grams of fiber per day.

Ways to Eat More Complex Carbs

Recipe to Try: Italian Zucchini-Topped Baked Potato

Complex carbohydrates can be a healthy part of every meal and snack. Pair them with protein and healthy fats for extra energy and satiety. Here are easy ways to incorporate them.

Don't be afraid of potatoes: One medium potato has fewer calories than a cup of pasta and boasts a whopping 4 grams fiber, 4 grams protein and 25 percent of your daily value of potassium. If you are having potatoes at dinner, fill the rest of your plate with nonstarchy vegetables, like broccoli or Brussels sprouts, and protein.

Choose whole grains over refined: Quinoa, farro, amaranth, barley, soba noodles, whole-wheat pasta and brown rice are complex carbohydrates that not only fill you up with fiber but also deliver extra vitamins and minerals you won't usually get from refined grain products like white rice or white pasta.

Add more plants to your plate: "You can't underestimate the importance of eating more plants, and if you're looking for complex carbs then vegetables and beans/legumes are an obvious choice," says Allison Knott, M.S., R.D.N., a registered dietitian based in Brooklyn, New York. "Consider adding spiralized root vegetables like sweet potatoes or parsnips to pasta dishes, swap meat for beans in chili and burgers (or go half-and-half), or add cooked leafy greens to soups, egg scrambles, pastas and sandwiches," she suggests.

Simplify your snack with complex carbs: Your snacks can be simple to make but full of complex carbohydrates. A sliced apple or banana topped with peanut butter delivers healthy good-for-you carbs. Or think outside the box and grab beans. "Snack on high-fiber options such as roasted chickpeas or roasted broad beans," says Knott.

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Related:
30 Healthy Low-Carb Foods to Eat
Healthy Recipes with Whole Grains
7-Day Meal Plan: Healthy Carb Swaps